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* [PATCH v5 3/4] iio: adc: Add Maxim max9611 ADC driver
From: Jacopo Mondi @ 2017-04-06 14:20 UTC (permalink / raw)
  To: geert-Td1EMuHUCqxL1ZNQvxDV9g,
	wsa+renesas-jBu1N2QxHDJrcw3mvpCnnVaTQe2KTcn/,
	magnus.damm-Re5JQEeQqe8AvxtiuMwx3w,
	laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw,
	jic23-DgEjT+Ai2ygdnm+yROfE0A, knaack.h-Mmb7MZpHnFY,
	lars-Qo5EllUWu/uELgA04lAiVw, pmeerw-jW+XmwGofnusTnJN9+BGXg,
	robh+dt-DgEjT+Ai2ygdnm+yROfE0A, mark.rutland-5wv7dgnIgG8
  Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA,
	linux-renesas-soc-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA
In-Reply-To: <1491488454-22468-1-git-send-email-jacopo+renesas-AW8dsiIh9cEdnm+yROfE0A@public.gmane.org>

Add iio driver for Maxim max9611 and max9612 current-sense amplifiers
with 12-bits ADC interface.

Datasheet publicly available at:
https://datasheets.maximintegrated.com/en/ds/MAX9611-MAX9612.pdf

Signed-off-by: Jacopo Mondi <jacopo+renesas-AW8dsiIh9cEdnm+yROfE0A@public.gmane.org>
---

Output of iio_info on Salvator-X board for max9611 chip installed on
VDD_0.8 lines.
The VDD_0.8 line powers the CPU cluster and on-board RAM.

        iio:device0: max9611
                5 channels found:
                        voltage0:  (input)
                        1 channel-specific attributes found:
                                attr 0: input value: 4.085000000
                        voltage1:  (input)
                        3 channel-specific attributes found:
                                attr 0: scale value: 14
                                attr 1: offset value: 1
                                attr 2: raw value: 59
                        power:  (input)
                        2 channel-specific attributes found:
                                attr 0: shunt_resistor value: 5.000
                                attr 1: input value: 663.404000000
                        current:  (input)
                        2 channel-specific attributes found:
                                attr 0: shunt_resistor value: 5.000
                                attr 1: input value: 817.000000000
                        temp:  (input)
                        2 channel-specific attributes found:
                                attr 0: scale value: 480.076812289
                                attr 1: raw value: 59

The collected information represent:

* voltage0 (current sense voltage) Vcsa
  voltage drop between RS+ and RS- input = 4,085 mV
* voltage1: (common input voltage) Vcim
  voltage at RS+ input = (59 - 1) * 14 = 812 mV
* current flowing on shunt resistor (Icsa)
  = Vcsa / Rshunt = 817 mA
* power load on the sensed line (Pload)
  = Vcim * Icsa = 663 m
* die temperature = (57 * 480.07) = 27360 milli Celsius

---
 drivers/iio/adc/Kconfig   |  10 +
 drivers/iio/adc/Makefile  |   1 +
 drivers/iio/adc/max9611.c | 585 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 596 insertions(+)
 create mode 100644 drivers/iio/adc/max9611.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index dedae7a..82f2e7b8 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -354,6 +354,16 @@ config MAX1363
 	  To compile this driver as a module, choose M here: the module will be
 	  called max1363.

+config	MAX9611
+	tristate "Maxim max9611/max9612 ADC driver"
+	depends on I2C
+	help
+	  Say yes here to build support for Maxim max9611/max9612 current sense
+	  amplifier with 12-bits ADC interface.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called max9611.
+
 config MCP320X
 	tristate "Microchip Technology MCP3x01/02/04/08"
 	depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index d001262..149f979 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_LTC2485) += ltc2485.o
 obj-$(CONFIG_MAX1027) += max1027.o
 obj-$(CONFIG_MAX11100) += max11100.o
 obj-$(CONFIG_MAX1363) += max1363.o
+obj-$(CONFIG_MAX9611) += max9611.o
 obj-$(CONFIG_MCP320X) += mcp320x.o
 obj-$(CONFIG_MCP3422) += mcp3422.o
 obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o
diff --git a/drivers/iio/adc/max9611.c b/drivers/iio/adc/max9611.c
new file mode 100644
index 0000000..f0b47fa
--- /dev/null
+++ b/drivers/iio/adc/max9611.c
@@ -0,0 +1,585 @@
+/*
+ * iio/adc/max9611.c
+ *
+ * Maxim max9611/max9612 high side current sense amplifier with
+ * 12-bit ADC interface.
+ *
+ * Copyright (C) 2017 Jacopo Mondi
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This driver supports input common-mode voltage, current-sense
+ * amplifier with programmable gains and die temperature reading from
+ * Maxim max9611/max9612.
+ *
+ * Op-amp, analog comparator, and watchdog functionalities are not
+ * supported by this driver.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+#define DRIVER_NAME			"max9611"
+
+/* max9611 register addresses */
+#define MAX9611_REG_CSA_DATA		0x00
+#define MAX9611_REG_RS_DATA		0x02
+#define MAX9611_REG_TEMP_DATA		0x08
+#define MAX9611_REG_CTRL1		0x0a
+#define MAX9611_REG_CTRL2		0x0b
+
+/* max9611 REG1 mux configuration options */
+#define MAX9611_MUX_MASK		GENMASK(3, 0)
+#define MAX9611_MUX_SENSE_1x		0x00
+#define MAX9611_MUX_SENSE_4x		0x01
+#define MAX9611_MUX_SENSE_8x		0x02
+#define MAX9611_INPUT_VOLT		0x03
+#define MAX9611_MUX_TEMP		0x06
+
+/* max9611 voltage (both csa and input) helper macros */
+#define MAX9611_VOLTAGE_SHIFT		0x04
+#define MAX9611_VOLTAGE_RAW(_r)		((_r) >> MAX9611_VOLTAGE_SHIFT)
+
+/*
+ * max9611 current sense amplifier voltage output:
+ * LSB and offset values depends on selected gain (1x, 4x, 8x)
+ *
+ * GAIN		LSB (nV)	OFFSET (LSB steps)
+ * 1x		107500		1
+ * 4x		26880		1
+ * 8x		13440		3
+ *
+ * The complete formula to calculate current sense voltage is:
+ *     (((adc_read >> 4) - offset) / ((1 / LSB) * 10^-3)
+ */
+#define MAX9611_CSA_1X_LSB_nV		107500
+#define MAX9611_CSA_4X_LSB_nV		26880
+#define MAX9611_CSA_8X_LSB_nV		13440
+
+#define MAX9611_CSA_1X_OFFS_RAW		1
+#define MAX9611_CSA_4X_OFFS_RAW		1
+#define MAX9611_CSA_8X_OFFS_RAW		3
+
+/*
+ * max9611 common input mode (CIM): LSB is 14mV, with 14mV offset at 25 C
+ *
+ * The complete formula to calculate input common voltage is:
+ *     (((adc_read >> 4) * 1000) - offset) / (1 / 14 * 1000)
+ */
+#define MAX9611_CIM_LSB_mV		14
+#define MAX9611_CIM_OFFSET_RAW		1
+
+/*
+ * max9611 temperature reading: LSB is 480 milli degrees Celsius
+ *
+ * The complete formula to calculate temperature is:
+ *     ((adc_read >> 7) * 1000) / (1 / 480 * 1000)
+ */
+#define MAX9611_TEMP_MAX_POS		0x7f80
+#define MAX9611_TEMP_MAX_NEG		0xff80
+#define MAX9611_TEMP_MIN_NEG		0xd980
+#define MAX9611_TEMP_MASK		GENMASK(7, 15)
+#define MAX9611_TEMP_SHIFT		0x07
+#define MAX9611_TEMP_RAW(_r)		((_r) >> MAX9611_TEMP_SHIFT)
+#define MAX9611_TEMP_SCALE_NUM		1000000
+#define MAX9611_TEMP_SCALE_DIV		2083
+
+struct max9611_dev {
+	struct device *dev;
+	struct i2c_client *i2c_client;
+	struct mutex lock;
+	unsigned int shunt_resistor_uohm;
+};
+
+enum max9611_conf_ids {
+	CONF_SENSE_1x,
+	CONF_SENSE_4x,
+	CONF_SENSE_8x,
+	CONF_IN_VOLT,
+	CONF_TEMP,
+};
+
+/**
+ * max9611_mux_conf - associate ADC mux configuration with register address
+ *		      where data shall be read from
+ */
+static const unsigned int max9611_mux_conf[][2] = {
+	/* CONF_SENSE_1x */
+	{ MAX9611_MUX_SENSE_1x, MAX9611_REG_CSA_DATA },
+	/* CONF_SENSE_4x */
+	{ MAX9611_MUX_SENSE_4x, MAX9611_REG_CSA_DATA },
+	/* CONF_SENSE_8x */
+	{ MAX9611_MUX_SENSE_8x, MAX9611_REG_CSA_DATA },
+	/* CONF_IN_VOLT */
+	{ MAX9611_INPUT_VOLT, MAX9611_REG_RS_DATA },
+	/* CONF_TEMP */
+	{ MAX9611_MUX_TEMP, MAX9611_REG_TEMP_DATA },
+};
+
+enum max9611_csa_gain {
+	CSA_GAIN_1x,
+	CSA_GAIN_4x,
+	CSA_GAIN_8x,
+};
+
+enum max9611_csa_gain_params {
+	CSA_GAIN_LSB_nV,
+	CSA_GAIN_OFFS_RAW,
+};
+
+/**
+ * max9611_csa_gain_conf - associate gain multiplier with LSB and
+ *			   offset values.
+ *
+ * Group together parameters associated with configurable gain
+ * on current sense amplifier path to ADC interface.
+ * Current sense read routine adjusts gain until it gets a meaningful
+ * value; use this structure to retrieve the correct LSB and offset values.
+ */
+static const unsigned int max9611_gain_conf[][2] = {
+	{ /* [0] CSA_GAIN_1x */
+		MAX9611_CSA_1X_LSB_nV,
+		MAX9611_CSA_1X_OFFS_RAW,
+	},
+	{ /* [1] CSA_GAIN_4x */
+		MAX9611_CSA_4X_LSB_nV,
+		MAX9611_CSA_4X_OFFS_RAW,
+	},
+	{ /* [2] CSA_GAIN_8x */
+		MAX9611_CSA_8X_LSB_nV,
+		MAX9611_CSA_8X_OFFS_RAW,
+	},
+};
+
+enum max9611_chan_addrs {
+	MAX9611_CHAN_VOLTAGE_INPUT,
+	MAX9611_CHAN_VOLTAGE_SENSE,
+	MAX9611_CHAN_TEMPERATURE,
+	MAX9611_CHAN_CURRENT_LOAD,
+	MAX9611_CHAN_POWER_LOAD,
+};
+
+static const struct iio_chan_spec max9611_channels[] = {
+	{
+	  .type			= IIO_TEMP,
+	  .info_mask_separate	= BIT(IIO_CHAN_INFO_RAW) |
+				  BIT(IIO_CHAN_INFO_SCALE),
+	  .address		= MAX9611_CHAN_TEMPERATURE,
+	},
+	{
+	  .type			= IIO_VOLTAGE,
+	  .info_mask_separate	= BIT(IIO_CHAN_INFO_PROCESSED),
+	  .address		= MAX9611_CHAN_VOLTAGE_SENSE,
+	  .indexed		= 1,
+	  .channel		= 0,
+	},
+	{
+	  .type			= IIO_VOLTAGE,
+	  .info_mask_separate	= BIT(IIO_CHAN_INFO_RAW)   |
+				  BIT(IIO_CHAN_INFO_SCALE) |
+				  BIT(IIO_CHAN_INFO_OFFSET),
+	  .address		= MAX9611_CHAN_VOLTAGE_INPUT,
+	  .indexed		= 1,
+	  .channel		= 1,
+	},
+	{
+	  .type			= IIO_CURRENT,
+	  .info_mask_separate	= BIT(IIO_CHAN_INFO_PROCESSED),
+	  .address		= MAX9611_CHAN_CURRENT_LOAD,
+	},
+	{
+	  .type			= IIO_POWER,
+	  .info_mask_separate	= BIT(IIO_CHAN_INFO_PROCESSED),
+	  .address		= MAX9611_CHAN_POWER_LOAD
+	},
+};
+
+/**
+ * max9611_read_single() - read a single value from ADC interface
+ *
+ * Data registers are 16 bit long, spread between two 8 bit registers
+ * with consecutive addresses.
+ * Configure ADC mux first, then read register at address "reg_addr".
+ * The smbus_read_word routine asks for 16 bits and the ADC is kind enough
+ * to return values from "reg_addr" and "reg_addr + 1" consecutively.
+ * Data are transmitted with big-endian ordering: MSB arrives first.
+ *
+ * @max9611: max9611 device
+ * @selector: index for mux and register configuration
+ * @raw_val: the value returned from ADC
+ */
+static int max9611_read_single(struct max9611_dev *max9611,
+			       enum max9611_conf_ids selector,
+			       u16 *raw_val)
+{
+	int ret;
+
+	u8 mux_conf = max9611_mux_conf[selector][0] & MAX9611_MUX_MASK;
+	u8 reg_addr = max9611_mux_conf[selector][1];
+
+	/*
+	 * Keep mutex lock held during read-write to avoid mux register
+	 * (CTRL1) re-configuration.
+	 */
+	mutex_lock(&max9611->lock);
+	ret = i2c_smbus_write_byte_data(max9611->i2c_client,
+					MAX9611_REG_CTRL1, mux_conf);
+	if (ret) {
+		dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
+			MAX9611_REG_CTRL1, mux_conf);
+		mutex_unlock(&max9611->lock);
+		return ret;
+	}
+
+	/*
+	 * need a delay here to make register configuration
+	 * stabilize. 1 msec at least, from empirical testing.
+	 */
+	usleep_range(1000, 2000);
+
+	ret = i2c_smbus_read_word_swapped(max9611->i2c_client, reg_addr);
+	if (ret < 0) {
+		dev_err(max9611->dev, "i2c read word from 0x%2x failed\n",
+			reg_addr);
+		mutex_unlock(&max9611->lock);
+		return ret;
+	}
+
+	*raw_val = ret;
+	mutex_unlock(&max9611->lock);
+
+	return 0;
+}
+
+/**
+ * max9611_read_csa_voltage() - read current sense amplifier output voltage
+ *
+ * Current sense amplifier output voltage is read through a configurable
+ * 1x, 4x or 8x gain.
+ * Start with plain 1x gain, and adjust gain control properly until a
+ * meaningful value is read from ADC output.
+ *
+ * @max9611: max9611 device
+ * @adc_raw: raw value read from ADC output
+ * @csa_gain: gain configuration option selector
+ */
+static int max9611_read_csa_voltage(struct max9611_dev *max9611,
+				    u16 *adc_raw,
+				    enum max9611_csa_gain *csa_gain)
+{
+	enum max9611_conf_ids gain_selectors[] = {
+		CONF_SENSE_1x,
+		CONF_SENSE_4x,
+		CONF_SENSE_8x
+	};
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < ARRAY_SIZE(gain_selectors); ++i) {
+		ret = max9611_read_single(max9611, gain_selectors[i], adc_raw);
+		if (ret)
+			return ret;
+
+		if (*adc_raw > 0) {
+			*csa_gain = gain_selectors[i];
+			return 0;
+		}
+	}
+
+	return -EIO;
+}
+
+static int max9611_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct max9611_dev *dev = iio_priv(indio_dev);
+	enum max9611_csa_gain gain_selector;
+	const unsigned int *csa_gain;
+	u16 adc_data;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+
+		switch (chan->address) {
+		case MAX9611_CHAN_TEMPERATURE:
+			ret = max9611_read_single(dev, CONF_TEMP,
+						  &adc_data);
+			if (ret)
+				return -EINVAL;
+
+			*val = MAX9611_TEMP_RAW(adc_data);
+			return IIO_VAL_INT;
+
+		case MAX9611_CHAN_VOLTAGE_INPUT:
+			ret = max9611_read_single(dev, CONF_IN_VOLT,
+						  &adc_data);
+			if (ret)
+				return -EINVAL;
+
+			*val = MAX9611_VOLTAGE_RAW(adc_data);
+			return IIO_VAL_INT;
+		}
+
+		break;
+
+	case IIO_CHAN_INFO_OFFSET:
+		/* MAX9611_CHAN_VOLTAGE_INPUT */
+		*val = MAX9611_CIM_OFFSET_RAW;
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+
+		switch (chan->address) {
+		case MAX9611_CHAN_TEMPERATURE:
+			*val = MAX9611_TEMP_SCALE_NUM;
+			*val2 = MAX9611_TEMP_SCALE_DIV;
+
+			return IIO_VAL_FRACTIONAL;
+
+		case MAX9611_CHAN_VOLTAGE_INPUT:
+			*val = MAX9611_CIM_LSB_mV;
+
+			return IIO_VAL_INT;
+		}
+
+		break;
+
+	case IIO_CHAN_INFO_PROCESSED:
+
+		switch (chan->address) {
+		case MAX9611_CHAN_VOLTAGE_SENSE:
+			/*
+			 * processed (mV): (raw - offset) * LSB (nV) / 10^6
+			 *
+			 * Even if max9611 can output raw csa voltage readings,
+			 * use a produced value as scale depends on gain.
+			 */
+			ret = max9611_read_csa_voltage(dev, &adc_data,
+						       &gain_selector);
+			if (ret)
+				return -EINVAL;
+
+			csa_gain = max9611_gain_conf[gain_selector];
+
+			adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
+			*val = MAX9611_VOLTAGE_RAW(adc_data) *
+			       csa_gain[CSA_GAIN_LSB_nV];
+			*val2 = 1000000;
+
+			return IIO_VAL_FRACTIONAL;
+
+		case MAX9611_CHAN_CURRENT_LOAD:
+			/* processed (mA): Vcsa (nV) / Rshunt (uOhm)  */
+			ret = max9611_read_csa_voltage(dev, &adc_data,
+						       &gain_selector);
+			if (ret)
+				return -EINVAL;
+
+			csa_gain = max9611_gain_conf[gain_selector];
+
+			adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
+			*val = MAX9611_VOLTAGE_RAW(adc_data) *
+			       csa_gain[CSA_GAIN_LSB_nV];
+			*val2 = dev->shunt_resistor_uohm;
+
+			return IIO_VAL_FRACTIONAL;
+
+		case MAX9611_CHAN_POWER_LOAD:
+			/*
+			 * processed (mW): Vin (mV) * Vcsa (uV) /
+			 *		   Rshunt (uOhm)
+			 */
+			ret = max9611_read_single(dev, CONF_IN_VOLT,
+						  &adc_data);
+			if (ret)
+				return -EINVAL;
+
+			adc_data -= MAX9611_CIM_OFFSET_RAW;
+			*val = MAX9611_VOLTAGE_RAW(adc_data) *
+			       MAX9611_CIM_LSB_mV;
+
+			ret = max9611_read_csa_voltage(dev, &adc_data,
+						       &gain_selector);
+			if (ret)
+				return -EINVAL;
+
+			csa_gain = max9611_gain_conf[gain_selector];
+
+			/* divide by 10^3 here to avoid 32bit overflow */
+			adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
+			*val *= MAX9611_VOLTAGE_RAW(adc_data) *
+				csa_gain[CSA_GAIN_LSB_nV] / 1000;
+			*val2 = dev->shunt_resistor_uohm;
+
+			return IIO_VAL_FRACTIONAL;
+		}
+
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t max9611_shunt_resistor_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct max9611_dev *max9611 = iio_priv(dev_to_iio_dev(dev));
+	unsigned int i, r;
+
+	i = max9611->shunt_resistor_uohm / 1000;
+	r = max9611->shunt_resistor_uohm % 1000;
+
+	return sprintf(buf, "%u.%03u\n", i, r);
+}
+
+static IIO_DEVICE_ATTR(in_power_shunt_resistor, 0444,
+		       max9611_shunt_resistor_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_current_shunt_resistor, 0444,
+		       max9611_shunt_resistor_show, NULL, 0);
+
+static struct attribute *max9611_attributes[] = {
+	&iio_dev_attr_in_power_shunt_resistor.dev_attr.attr,
+	&iio_dev_attr_in_current_shunt_resistor.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group max9611_attribute_group = {
+	.attrs = max9611_attributes,
+};
+
+static const struct iio_info indio_info = {
+	.driver_module	= THIS_MODULE,
+	.read_raw	= max9611_read_raw,
+	.attrs		= &max9611_attribute_group,
+};
+
+static int max9611_init(struct max9611_dev *max9611)
+{
+	struct i2c_client *client = max9611->i2c_client;
+	u16 regval;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_WRITE_BYTE	|
+				     I2C_FUNC_SMBUS_READ_WORD_DATA)) {
+		dev_err(max9611->dev,
+			"I2c adapter does not support smbus write_byte or read_word functionalities: aborting probe.\n");
+		return -EINVAL;
+	}
+
+	/* Make sure die temperature is in range to test communications. */
+	ret = max9611_read_single(max9611, CONF_TEMP, &regval);
+	if (ret)
+		return ret;
+
+	regval = ret & MAX9611_TEMP_MASK;
+
+	if ((regval > MAX9611_TEMP_MAX_POS &&
+	     regval < MAX9611_TEMP_MIN_NEG) ||
+	     regval > MAX9611_TEMP_MAX_NEG) {
+		dev_err(max9611->dev,
+			"Invalid value received from ADC 0x%4x: aborting\n",
+			regval);
+		return -EIO;
+	}
+
+	/* Mux shall be zeroed back before applying other configurations */
+	ret = i2c_smbus_write_byte_data(max9611->i2c_client,
+					MAX9611_REG_CTRL1, 0);
+	if (ret) {
+		dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
+			MAX9611_REG_CTRL1, 0);
+		return ret;
+	}
+
+	ret = i2c_smbus_write_byte_data(max9611->i2c_client,
+					MAX9611_REG_CTRL2, 0);
+	if (ret) {
+		dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
+			MAX9611_REG_CTRL2, 0);
+		return ret;
+	}
+	usleep_range(1000, 2000);
+
+	return 0;
+}
+
+static const struct of_device_id max9611_of_table[] = {
+	{.compatible = "maxim,max9611", .data = "max9611"},
+	{.compatible = "maxim,max9612", .data = "max9612"},
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, max9611_of_table);
+static int max9611_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	const char * const shunt_res_prop = "shunt-resistor-micro-ohms";
+	const struct device_node *of_node = client->dev.of_node;
+	const struct of_device_id *of_id =
+		of_match_device(max9611_of_table, &client->dev);
+	struct max9611_dev *max9611;
+	struct iio_dev *indio_dev;
+	unsigned int of_shunt;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*max9611));
+	if (IS_ERR(indio_dev))
+		return PTR_ERR(indio_dev);
+
+	i2c_set_clientdata(client, indio_dev);
+
+	max9611			= iio_priv(indio_dev);
+	max9611->dev		= &client->dev;
+	max9611->i2c_client	= client;
+	mutex_init(&max9611->lock);
+
+	ret = of_property_read_u32(of_node, shunt_res_prop, &of_shunt);
+	if (ret) {
+		dev_err(&client->dev,
+			"Missing %s property for %s node\n",
+			shunt_res_prop, of_node->full_name);
+		return ret;
+	}
+	max9611->shunt_resistor_uohm = of_shunt;
+
+	ret = max9611_init(max9611);
+	if (ret)
+		return ret;
+
+	indio_dev->dev.parent	= &client->dev;
+	indio_dev->dev.of_node	= client->dev.of_node;
+	indio_dev->name		= of_id->data;
+	indio_dev->modes	= INDIO_DIRECT_MODE;
+	indio_dev->info		= &indio_info;
+	indio_dev->channels	= max9611_channels;
+	indio_dev->num_channels	= ARRAY_SIZE(max9611_channels);
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static struct i2c_driver max9611_driver = {
+	.driver = {
+		   .name = DRIVER_NAME,
+		   .owner = THIS_MODULE,
+		   .of_match_table = max9611_of_table,
+	},
+	.probe = max9611_probe,
+};
+module_i2c_driver(max9611_driver);
+
+MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas-AW8dsiIh9cEdnm+yROfE0A@public.gmane.org>");
+MODULE_DESCRIPTION("Maxim max9611/12 current sense amplifier with 12bit ADC");
+MODULE_LICENSE("GPL v2");
--
2.7.4

^ permalink raw reply related

* [PATCH v5 2/4] iio: Documentation: Add max9611 sysfs documentation
From: Jacopo Mondi @ 2017-04-06 14:20 UTC (permalink / raw)
  To: geert, wsa+renesas, magnus.damm, laurent.pinchart, jic23,
	knaack.h, lars, pmeerw, robh+dt, mark.rutland
  Cc: linux-iio, linux-renesas-soc, devicetree
In-Reply-To: <1491488454-22468-1-git-send-email-jacopo+renesas@jmondi.org>

Add documentation for max9611 driver.
Document attributes describing value of shunt resistor installed between
RS+ and RS- voltage sense inputs.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 Documentation/ABI/testing/sysfs-bus-iio-adc-max9611 | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-max9611

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-max9611 b/Documentation/ABI/testing/sysfs-bus-iio-adc-max9611
new file mode 100644
index 0000000..6d2d2b0
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-max9611
@@ -0,0 +1,17 @@
+What:		/sys/bus/iio/devices/iio:deviceX/in_power_shunt_resistor
+Date:		March 2017
+KernelVersion:	4.12
+Contact:	linux-iio@vger.kernel.org
+Description: 	The value of the shunt resistor used to compute power drain on
+                common input voltage pin (RS+). In Ohms.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_current_shunt_resistor
+Date:		March 2017
+KernelVersion:	4.12
+Contact:	linux-iio@vger.kernel.org
+Description: 	The value of the shunt resistor used to compute current flowing
+                between RS+ and RS- voltage sense inputs. In Ohms.
+
+These attributes describe a single physical component, exposed as two distinct
+attributes as it is used to calculate two different values: power load and
+current flowing between RS+ and RS- inputs.
-- 
2.7.4

^ permalink raw reply related

* [PATCH v5 1/4] Documentation: dt-bindings: iio: Add max9611 ADC
From: Jacopo Mondi @ 2017-04-06 14:20 UTC (permalink / raw)
  To: geert-Td1EMuHUCqxL1ZNQvxDV9g,
	wsa+renesas-jBu1N2QxHDJrcw3mvpCnnVaTQe2KTcn/,
	magnus.damm-Re5JQEeQqe8AvxtiuMwx3w,
	laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw,
	jic23-DgEjT+Ai2ygdnm+yROfE0A, knaack.h-Mmb7MZpHnFY,
	lars-Qo5EllUWu/uELgA04lAiVw, pmeerw-jW+XmwGofnusTnJN9+BGXg,
	robh+dt-DgEjT+Ai2ygdnm+yROfE0A, mark.rutland-5wv7dgnIgG8
  Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA,
	linux-renesas-soc-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA
In-Reply-To: <1491488454-22468-1-git-send-email-jacopo+renesas-AW8dsiIh9cEdnm+yROfE0A@public.gmane.org>

Add device tree bindings documentation for Maxim max9611/max9612 current
sense amplifier.

Signed-off-by: Jacopo Mondi <jacopo+renesas-AW8dsiIh9cEdnm+yROfE0A@public.gmane.org>
---
 .../devicetree/bindings/iio/adc/max9611.txt        | 27 ++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/max9611.txt

diff --git a/Documentation/devicetree/bindings/iio/adc/max9611.txt b/Documentation/devicetree/bindings/iio/adc/max9611.txt
new file mode 100644
index 0000000..ffb046a
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/max9611.txt
@@ -0,0 +1,27 @@
+* Maxim max9611/max9612 current sense amplifier with 12-bits ADC interface
+
+Maxim max9611/max9612 is an high-side current sense amplifier with integrated
+12-bits ADC communicating over I2c bus.
+The device node for this driver shall be a child of a I2c controller.
+
+Required properties
+  - compatible: Should be "maxim,max9611" or "maxim,max9612"
+  - reg: The 7-bits long I2c address of the device
+  - shunt-resistor-micro-homs: Value, in micro Ohms, of the current sense shunt
+			        resistor
+
+Example:
+
+&i2c4 {
+	csa: adc@7c {
+		compatible = "maxim,max9611";
+		reg = <0x7c>;
+
+		shunt-resistor-micro-ohms = <5000>;
+	};
+};
+
+This device node describes a current sense amplifier sitting on I2c4 bus
+with address 0x7c (read address is 0xf9, write address is 0xf8).
+A sense resistor of 0,005 Ohm is installed between RS+ and RS- current-sensing
+inputs.
--
2.7.4

^ permalink raw reply related

* [PATCH v5 0/4] iio: adc: Maxim max9611 driver
From: Jacopo Mondi @ 2017-04-06 14:20 UTC (permalink / raw)
  To: geert-Td1EMuHUCqxL1ZNQvxDV9g,
	wsa+renesas-jBu1N2QxHDJrcw3mvpCnnVaTQe2KTcn/,
	magnus.damm-Re5JQEeQqe8AvxtiuMwx3w,
	laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw,
	jic23-DgEjT+Ai2ygdnm+yROfE0A, knaack.h-Mmb7MZpHnFY,
	lars-Qo5EllUWu/uELgA04lAiVw, pmeerw-jW+XmwGofnusTnJN9+BGXg,
	robh+dt-DgEjT+Ai2ygdnm+yROfE0A, mark.rutland-5wv7dgnIgG8
  Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA,
	linux-renesas-soc-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA

Hi there,
   fifth round for max9611/9612 ADC iio driver.

I have changed dt-bindings to use "shunt-resistor-micro-ohms" as ina2xx does,
and changed the sysfs attributes exposing the shunt resistor value to use Ohms
as units.

Output of iio_info on Salvator-X board for max9611 chip installed on
VDD_0.8 lines.
The VDD_0.8 line powers the CPU cluster and on-board RAM.

        iio:device0: max9611
                5 channels found:
                        voltage0:  (input)
                        1 channel-specific attributes found:
                                attr 0: input value: 4.085000000
                        voltage1:  (input)
                        3 channel-specific attributes found:
                                attr 0: scale value: 14
                                attr 1: offset value: 1
                                attr 2: raw value: 59
                        power:  (input)
                        2 channel-specific attributes found:
                                attr 0: shunt_resistor value: 5.000
                                attr 1: input value: 663.404000000
                        current:  (input)
                        2 channel-specific attributes found:
                                attr 0: shunt_resistor value: 5.000
                                attr 1: input value: 817.000000000
                        temp:  (input)
                        2 channel-specific attributes found:
                                attr 0: scale value: 480.076812289
                                attr 1: raw value: 59

The collected information represent:

* voltage0 (current sense voltage) Vcsa
  voltage drop between RS+ and RS- input = 4,085 mV
* voltage1: (common input voltage) Vcim
  voltage at RS+ input = (59 - 1) * 14 = 812 mV
* current flowing on shunt resistor (Icsa)
  = Vcsa / Rshunt = 817 mA
* power load on the sensed line (Pload)
  = Vcim * Icsa = 663 m
* die temperature = (57 * 480.07) = 27360 milli Celsius

v1 -> v2:
- Drop wildcard (max961x) in driver, documentation and dt-bindings. Use
  max9611 instead.
- Make 3 processed channels for csa voltage, csa current and power load
- Remove wrapper functions around i2c buffer access
- Add locking in read_raw()
- Make 2 separate attributes for shunt resistor: current and power
- Renamed shunt resistor attribute
- Fixed several review comments

v2 -> v3:
- Incorporated Geert's suggestions on using a more generic name for ADC nodes
  in device tree
- Changed "maxim,shunt-resistor-uohm" to "shunt-resistor-uohm"
- Update documentation accordingly to the two previous changes

v3 -> v4:
- Move all locking to read_single() function
- Re-structure read_raw() with Jonathan's and Peter's comments
- Rename some defines pre-pending MAX9611 prefix
- Use values from .comaptible entries for device name
- Change temperature scale to have a value in milli Celsius
- Simplify init routine using read_single

v4 -> v5:
- Change device tree property name for shunt resistor in
  "shunt-resistor-micro-ohms"
- Display shunt resistor value with Ohms as units in sysfs

Jacopo Mondi (4):
  Documentation: dt-bindings: iio: Add max9611 ADC
  iio: Documentation: Add max9611 sysfs documentation
  iio: adc: Add Maxim max9611 ADC driver
  arm64: dts: salvator-x: Add current sense amplifiers

 .../ABI/testing/sysfs-bus-iio-adc-max9611          |  17 +
 .../devicetree/bindings/iio/adc/max9611.txt        |  27 +
 arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dts |  18 +
 drivers/iio/adc/Kconfig                            |  10 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/max9611.c                          | 587 +++++++++++++++++++++
 6 files changed, 660 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-max9611
 create mode 100644 Documentation/devicetree/bindings/iio/adc/max9611.txt
 create mode 100644 drivers/iio/adc/max9611.c

--
2.7.4

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^ permalink raw reply

* Re: [PATCH] [media] imx: csi: retain current field order and colorimetry setting as default
From: Hans Verkuil @ 2017-04-06 14:20 UTC (permalink / raw)
  To: Philipp Zabel, Steve Longerbeam
  Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A, mark.rutland-5wv7dgnIgG8,
	shawnguo-DgEjT+Ai2ygdnm+yROfE0A, kernel-bIcnvbaLZ9MEGnE8C9+IrQ,
	fabio.estevam-3arQi8VN3Tc, linux-I+IVW8TIWO2tmTQ+vhA3Yw,
	mchehab-DgEjT+Ai2ygdnm+yROfE0A, nick-gcszYUEDH4VrovVCs/uTlw,
	markus.heiser-O6JHGLzbNUwb1SvskN2V4Q,
	laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw,
	bparrot-l0cyMroinI0, geert-Td1EMuHUCqxL1ZNQvxDV9g,
	arnd-r2nGTMty4D4, sudipm.mukherjee-Re5JQEeQqe8AvxtiuMwx3w,
	minghsiu.tsai-NuS5LvNUpcJWk0Htik3J/w,
	tiffany.lin-NuS5LvNUpcJWk0Htik3J/w,
	jean-christophe.trotin-qxv4g6HH51o,
	horms+renesas-/R6kz+dDXgpPR4JQBCEnsQ,
	niklas.soderlund+renesas-1zkq55x86MTxsAP9Fp7wbw,
	robert.jarzmik-GANU6spQydw, songjun.wu-UWL1GkI3JZL3oGB3hsPCZA,
	andrew-ct.chen-NuS5LvNUpcJWk0Htik3J/w,
	gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r,
	shuah-DgEjT+Ai2ygdnm+yROfE0A, sakari.ailus-VuQAYsv1563Yd54FQh9/CA,
	pavel-+ZI9xUNit7I, devicetree-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	linux-media-u79uwXL29TY76Z2rM5mHXA, devel
In-Reply-To: <1491486929.2392.29.camel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>

On 04/06/2017 03:55 PM, Philipp Zabel wrote:
> If the the field order is set to ANY in set_fmt, choose the currently
> set field order. If the colorspace is set to DEFAULT, choose the current
> colorspace.  If any of xfer_func, ycbcr_enc or quantization are set to
> DEFAULT, either choose the current setting, or the default setting for the
> new colorspace, if non-DEFAULT colorspace was given.
> 
> This allows to let field order and colorimetry settings be propagated
> from upstream by calling media-ctl on the upstream entity source pad,
> and then call media-ctl on the sink pad to manually set the input frame
> interval, without changing the already set field order and colorimetry
> information.
> 
> Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> ---
> This is based on imx-media-staging-md-v14, and it is supposed to allow
> configuring the pipeline with media-ctl like this:
> 
> 1) media-ctl --set-v4l2 "'tc358743 1-000f':0[fmt:UYVY8_1X16/1920x1080]"
> 2) media-ctl --set-v4l2 "'imx6-mipi-csi2':1[fmt:UYVY8_1X16/1920x108]"
> 3) media-ctl --set-v4l2 "'ipu1_csi0_mux':2[fmt:UYVY8_1X16/1920x1080]"
> 4) media-ctl --set-v4l2 "'ipu1_csi0':0[fmt:UYVY8_1X16/1920x1080@1/60]"
> 5) media-ctl --set-v4l2 "'ipu1_csi0':2[fmt:AYUV32/1920x1080@1/30]"
> 
> Without having step 4) overwrite the colorspace and field order set on
> 'ipu1_csi0':0 by the propagation in step 3).
> ---
>  drivers/staging/media/imx/imx-media-csi.c | 34 +++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
> index 64dc454f6b371..d94ce1de2bf05 100644
> --- a/drivers/staging/media/imx/imx-media-csi.c
> +++ b/drivers/staging/media/imx/imx-media-csi.c
> @@ -1325,6 +1325,40 @@ static int csi_set_fmt(struct v4l2_subdev *sd,
>  	csi_try_fmt(priv, sensor, cfg, sdformat, crop, compose, &cc);
>  
>  	fmt = __csi_get_fmt(priv, cfg, sdformat->pad, sdformat->which);
> +
> +	/* Retain current field setting as default */
> +	if (sdformat->format.field == V4L2_FIELD_ANY)
> +		sdformat->format.field = fmt->field;

sdformat->format.field should never be FIELD_ANY. If it is, then that's a
subdev bug and I'm pretty sure FIELD_NONE was intended.

> +
> +	/* Retain current colorspace setting as default */
> +	if (sdformat->format.colorspace == V4L2_COLORSPACE_DEFAULT) {
> +		sdformat->format.colorspace = fmt->colorspace;

No! Subdevs should never return COLORSPACE_DEFAULT. If they do, then fix
them. If this happens a lot (I'm not sure how reliably subdevs fill this
in) you could set it to COLORSPACE_RAW. Perhaps with a WARN_ON_ONCE.

> +		if (sdformat->format.xfer_func == V4L2_XFER_FUNC_DEFAULT)
> +			sdformat->format.xfer_func = fmt->xfer_func;
> +		if (sdformat->format.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT)
> +			sdformat->format.ycbcr_enc = fmt->ycbcr_enc;
> +		if (sdformat->format.quantization == V4L2_QUANTIZATION_DEFAULT)
> +			sdformat->format.quantization = fmt->quantization;

Nack. This is meaningless.

> +	} else {
> +		if (sdformat->format.xfer_func == V4L2_XFER_FUNC_DEFAULT) {
> +			sdformat->format.xfer_func =
> +				V4L2_MAP_XFER_FUNC_DEFAULT(
> +						sdformat->format.colorspace);
> +		}
> +		if (sdformat->format.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT) {
> +			sdformat->format.ycbcr_enc =
> +				V4L2_MAP_YCBCR_ENC_DEFAULT(
> +						sdformat->format.colorspace);
> +		}
> +		if (sdformat->format.quantization == V4L2_QUANTIZATION_DEFAULT) {
> +			sdformat->format.quantization =
> +				V4L2_MAP_QUANTIZATION_DEFAULT(
> +						cc->cs != IPUV3_COLORSPACE_YUV,
> +						sdformat->format.colorspace,
> +						sdformat->format.ycbcr_enc);
> +		}

This isn't wrong, but it is perfectly fine to keep the DEFAULT here and let
the application call V4L2_MAP_.

I get the feeling this patch is a workaround for subdev errors. Either that,
or the commit log doesn't give me enough information to really understand the
problem that's being addressed here.

Regards,

	Hans

> +	}
> +
>  	*fmt = sdformat->format;
>  
>  	if (sdformat->pad == CSI_SINK_PAD) {
> 

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^ permalink raw reply

* Re: [PATCH v3 0/9] Fix issues and factorize arm/arm64 capacity information code
From: Juri Lelli @ 2017-04-06 14:14 UTC (permalink / raw)
  To: linux-kernel-u79uwXL29TY76Z2rM5mHXA
  Cc: linux-pm-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	devicetree-u79uwXL29TY76Z2rM5mHXA, peterz-wEGCiKHe2LqWVfeAwA7xHQ,
	vincent.guittot-QSEj5FYQhm4dnm+yROfE0A,
	robh+dt-DgEjT+Ai2ygdnm+yROfE0A, mark.rutland-5wv7dgnIgG8,
	linux-lFZ/pmaqli7XmaaqVzeoHQ, sudeep.holla-5wv7dgnIgG8,
	lorenzo.pieralisi-5wv7dgnIgG8, catalin.marinas-5wv7dgnIgG8,
	will.deacon-5wv7dgnIgG8, morten.rasmussen-5wv7dgnIgG8,
	dietmar.eggemann-5wv7dgnIgG8, broonie-DgEjT+Ai2ygdnm+yROfE0A,
	gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r
In-Reply-To: <20170327131825.32134-1-juri.lelli-5wv7dgnIgG8@public.gmane.org>

Hi,

On 27/03/17 14:18, Juri Lelli wrote:
> Hi,
> 
> arm and arm64 topology.c share a lot of code related to parsing of capacity
> information. This is v3 of a solution [1] (based on Will's, Catalin's and
> Mark's off-line suggestions) to move such common code in a single place:
> drivers/base/arch_topology.c (by creating such file and conditionally compiling
> it for arm and arm64 only).
> 
> First 4 patches are actually fixes for the current code.
> 
> Patch 5 is the actual refactoring.
> 
> Patch 6 is a minor change suggested by Greg and can be squashed as needed.
> 
> Patch 7 removes one of the extern symbols by changing a bit the now common
> code.
> 
> Patch 8 removes the remaining externs (as required by Russell during v1 review)
> by creating a new header file include/linux/arch_topology.h and including that
> from arm, arm64 and drivers.
> 
> Last patch addresses Dietmar's comments to v1 and adds a 'atd_' prefix to
> interfaces exported by drivers code and used by arch (and potentially others in
> the future).
> 
> Changes from v2:
> 
>  - rebase on top of 4.11-rc4
>  - fix various problems pointed out by Greg, thanks for the review!
>    (see patch 5 for details)
> 

Thanks Vincent for your comments.

Everybody else, ping?

Thanks,

- Juri
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^ permalink raw reply

* Re: [PATCH 1/3] ASoC: cs35l35: Improve power down time
From: Brian Austin @ 2017-04-06 14:12 UTC (permalink / raw)
  To: Charles Keepax
  Cc: mark.rutland, devicetree, brian.austin, alsa-devel, patches,
	lgirdwood, Paul.Handrigan, robh+dt, broonie
In-Reply-To: <1491483134-28079-1-git-send-email-ckeepax@opensource.wolfsonmicro.com>

On Thu, 6 Apr 2017, Charles Keepax wrote:

> Shorten the time it takes to power down the amp by disabling the volume
> ramp whilst doing the final shutdown. The driver has already muted the
> amplifier at this stage so doing the volume ramp serves no purpose.
> 
> Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
For the series

Acked-by: Brian Austin <brian.austin@cirrus.com>

^ permalink raw reply

* Re: [PATCH 2/3] of/fdt: introduce of_scan_flat_dt_subnodes and of_get_flat_dt_phandle
From: Rob Herring @ 2017-04-06 14:09 UTC (permalink / raw)
  To: Nicholas Piggin
  Cc: Benjamin Herrenschmidt, Michael Ellerman,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linuxppc-dev,
	Frank Rowand
In-Reply-To: <20170406103829.67d462e1-a5aMA/AkCkgK5Ils6ZIQy0EOCMrvLtNR@public.gmane.org>

On Wed, Apr 5, 2017 at 7:38 PM, Nicholas Piggin <npiggin-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On Thu, 06 Apr 2017 06:58:01 +1000
> Benjamin Herrenschmidt <benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org> wrote:
>
>> On Wed, 2017-04-05 at 10:58 -0500, Rob Herring wrote:
>> > Well, I'd like to avoid expanding usage of flat DT parsing in the
>> > kernel. But you could just put this function into arch/powerpc and I'd
>> > never see it, but I like that even less. Mainly, I just wanted to
>> > raise the point.
>> >
>> > Your argument works until you need that setup in assembly code, then
>> > you are in the situation that you need to either handle the setup in
>> > bootloader/firmware or have an simple way to determine that condition.
>>
>> The main issue is that changing that is a very very invasive change in
>> an extremely fragile and rather nasty area of code shared by 32 and 64-
>> bit for which we don't even have easy access to all the machines to
>> test with anymore :)
>>
>> It's probably not impossible, but it would delay the new cpu feature
>> stuff that Nick is making by a lot, probably monthes, making it nearly
>> impossible to get back into distros etc...
>>
>> So while it might be something to consider, I would definitely keep
>> that as a separate unit of work to do later.
>
> Yeah, it's no longer a "drop in" replacement for existing features
> testing if we do this, which makes it hard to backport too (we will
> need this for compatibility with future firmware, so it will have to
> go into distro kernels.)
>
> Given that it's quite a small addition to of/fdt code, hopefully
> that gives you a reasonable justification to accept it.
>
> If you prefer not to, that's okay, but I think we would have to carry
> it in arch/powerpc at least for a time, because of the schedule we're
> working to for POWER9 enablement. As a longer term item I agree with you
> and Ben, it would be worth considering unflattening earlier.

As I mentioned, keeping it in arch/powerpc I like even less. So this is fine.

Rob
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* Re: [PATCH] [media] imx: csi: retain current field order and colorimetry setting as default
From: Russell King - ARM Linux @ 2017-04-06 14:05 UTC (permalink / raw)
  To: Philipp Zabel
  Cc: Steve Longerbeam, robh+dt, mark.rutland, shawnguo, kernel,
	fabio.estevam, mchehab, hverkuil, nick, markus.heiser,
	laurent.pinchart+renesas, bparrot, geert, arnd, sudipm.mukherjee,
	minghsiu.tsai, tiffany.lin, jean-christophe.trotin, horms+renesas,
	niklas.soderlund+renesas, robert.jarzmik, songjun.wu,
	andrew-ct.chen, gregkh, shuah, sakari.ailus, pavel, devicetree,
	linux-kernel, linux-arm-kernel, linux-media
In-Reply-To: <1491486929.2392.29.camel@pengutronix.de>

On Thu, Apr 06, 2017 at 03:55:29PM +0200, Philipp Zabel wrote:
> +
> +	/* Retain current field setting as default */
> +	if (sdformat->format.field == V4L2_FIELD_ANY)
> +		sdformat->format.field = fmt->field;
> +
> +	/* Retain current colorspace setting as default */
> +	if (sdformat->format.colorspace == V4L2_COLORSPACE_DEFAULT) {
> +		sdformat->format.colorspace = fmt->colorspace;
> +		if (sdformat->format.xfer_func == V4L2_XFER_FUNC_DEFAULT)
> +			sdformat->format.xfer_func = fmt->xfer_func;
> +		if (sdformat->format.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT)
> +			sdformat->format.ycbcr_enc = fmt->ycbcr_enc;
> +		if (sdformat->format.quantization == V4L2_QUANTIZATION_DEFAULT)
> +			sdformat->format.quantization = fmt->quantization;
> +	} else {
> +		if (sdformat->format.xfer_func == V4L2_XFER_FUNC_DEFAULT) {
> +			sdformat->format.xfer_func =
> +				V4L2_MAP_XFER_FUNC_DEFAULT(
> +						sdformat->format.colorspace);
> +		}
> +		if (sdformat->format.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT) {
> +			sdformat->format.ycbcr_enc =
> +				V4L2_MAP_YCBCR_ENC_DEFAULT(
> +						sdformat->format.colorspace);
> +		}
> +		if (sdformat->format.quantization == V4L2_QUANTIZATION_DEFAULT) {
> +			sdformat->format.quantization =
> +				V4L2_MAP_QUANTIZATION_DEFAULT(
> +						cc->cs != IPUV3_COLORSPACE_YUV,
> +						sdformat->format.colorspace,
> +						sdformat->format.ycbcr_enc);
> +		}
> +	}

Would it make sense for this to be a helper function?

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

^ permalink raw reply

* Re: [PATCH 3/4] pwm: tegra: Add DT binding details to configure pin in suspends/resume
From: Jon Hunter @ 2017-04-06 14:03 UTC (permalink / raw)
  To: Laxman Dewangan, Thierry Reding
  Cc: robh+dt, mark.rutland, linux-pwm, devicetree, linux-tegra,
	linux-kernel, Linus Walleij
In-Reply-To: <58E6405E.5020402@nvidia.com>


On 06/04/17 14:19, Laxman Dewangan wrote:
> 
> On Thursday 06 April 2017 06:33 PM, Thierry Reding wrote:
>> * PGP Signed by an unknown key
>>
>> On Thu, Apr 06, 2017 at 09:57:09AM +0100, Jon Hunter wrote:
>>> On 05/04/17 15:13, Laxman Dewangan wrote:
>>>> +state of the system. The configuration of pin is provided via the
>>>> pinctrl
>>>> +DT node as detailed in the pinctrl DT binding document
>>>> +    Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
>>>> +
>>>> +The PWM node will have following optional properties.
>>>> +pinctrl-names:    Pin state names. Must be "suspend" and "resume".
>>> Why not just use the pre-defined names here? There is a pre-defined name
>>> for "default", "idle" and "sleep" and then you can use the following
>>> APIs and avoid the lookup of the state ...
>>>
>>> pinctrl_pm_select_default_state()
>>> pinctrl_pm_select_idle_state()
>>> pinctrl_pm_select_sleep_state()
>>>
>>> Note for i2c [0][1], I used "default" as the active/on state (which I
>>> know is not that descriptive) and then used 'idle' as the suspended
>>> state. This way we don't need any custom names.
>> Agreed, I think that's how these states are meant to be used.
> I did quick grep for the pinctrl_pm_select_* functions in the code tree
> and found usage of these APIs in some of the places.
> I am taking the reference of i2c-st, i2c-nomadic and
> extcon/extcon-usb-gpio.c drivers and from this the interpretation is
> 
> default state: When interface active and transfer need to be done in IO
> interface.
> idle state: Active state of the system but interface is not active, put
> in non-active state of the interface.
> sleep state: When system entering into suspend and IO interface is going
> to be inactive.
> 
> So in PWM case, we will need the "default" and "sleep" state.
> 
> In suspend(), set the "sleep" state and in resume, set the "default" state.
> 
> + Linus W as I refereed his st/nomadik driver for reference.

I mis-spoke before, I used 'idle' for i2c as I am using it in the
context of the runtime-pm callbacks and not suspend. So sleep is fine
with me.

Jon

-- 
nvpublic

^ permalink raw reply

* Re: [PATCH] of: change fixup of dma-ranges size to error
From: Rob Herring @ 2017-04-06 14:03 UTC (permalink / raw)
  To: Frank Rowand
  Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
In-Reply-To: <1491459529-31391-1-git-send-email-frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

On Thu, Apr 6, 2017 at 1:18 AM,  <frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> From: Frank Rowand <frank.rowand-7U/KSKJipcs@public.gmane.org>
>
> of_dma_get_range() has workaround code to fixup a device tree that
> incorrectly specified a mask instead of a size for property
> dma-ranges.  That device tree was fixed a year ago in v4.6, so
> the workaround is no longer needed.  Leave a data validation
> check in place, but no longer do the fixup.  Move the check
> one level deeper in the call stack so that other possible users
> of dma-ranges will also be protected.
>
> The fix to the device tree was in
> commit c91cb9123cdd ("dtb: amd: Fix DMA ranges in device tree").

NACK. This was by design. You can't represent a size of 2^64 or 2^32.
Well, technically you can for the latter, but then you have to grow
#size-cells to 2 for an otherwise all 32-bit system which seems kind
of pointless and wasteful. You could further restrict this to only
allow ~0 and not just any case with bit 0 set.

I'm pretty sure AMD is not the only system. There were 32-bit systems too.

Rob
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^ permalink raw reply

* Re: [PATCH v5 7/9] clk: hi6220: add debug APB clock
From: Leo Yan @ 2017-04-06 13:59 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Michael Turquette, Mathieu Poirier, Guodong Xu, John Stultz,
	linux-doc-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	linux-arm-msm-u79uwXL29TY76Z2rM5mHXA,
	linux-soc-u79uwXL29TY76Z2rM5mHXA,
	linux-clk-u79uwXL29TY76Z2rM5mHXA,
	mike.leach-QSEj5FYQhm4dnm+yROfE0A, Suzuki.Poulose-5wv7dgnIgG8,
	sudeep.holla-5wv7dgnIgG8
In-Reply-To: <20170404215109.GH18246-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

On Tue, Apr 04, 2017 at 02:51:09PM -0700, Stephen Boyd wrote:
> On 03/26, Leo Yan wrote:
> > The debug APB clock is absent in hi6220 driver, so this patch is to add
> > support for it.
> > 
> > Signed-off-by: Leo Yan <leo.yan-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> > ---
> 
> Applied to clk-next.

Thanks a lot :)

> I suspect we don't need a topic branch for
> the DT header because arm-soc won't be taking the dts side of the
> changes?

I think this question is leaving for maintainers.

Thanks,
Leo Yan
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^ permalink raw reply

* Re: [PATCH V10 06/12] of: device: Fix overflow of coherent_dma_mask
From: Rob Herring @ 2017-04-06 13:56 UTC (permalink / raw)
  To: Robin Murphy
  Cc: Catalin Marinas, Will Deacon, Sinan Kaya, Frank Rowand,
	linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Tomasz Nowicki,
	linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Len Brown,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Arnd Bergmann,
	linux-arm-msm, bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Greg Kroah-Hartman, Rafael J. Wysocki,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linux IOMMU,
	Sudeep Holla <sudeep.holla>
In-Reply-To: <b081f333-084d-ffa5-635f-f7f1c0232ac3-5wv7dgnIgG8@public.gmane.org>

On Thu, Apr 6, 2017 at 5:24 AM, Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org> wrote:
> On 06/04/17 08:01, Frank Rowand wrote:
>> On 04/04/17 03:18, Sricharan R wrote:
>>> Size of the dma-range is calculated as coherent_dma_mask + 1
>>> and passed to arch_setup_dma_ops further. It overflows when
>>> the coherent_dma_mask is set for full 64 bits 0xFFFFFFFFFFFFFFFF,
>>> resulting in size getting passed as 0 wrongly. Fix this by
>>> passsing in max(mask, mask + 1). Note that in this case
>>> when the mask is set to full 64bits, we will be passing the mask
>>> itself to arch_setup_dma_ops instead of the size. The real fix
>>> for this should be to make arch_setup_dma_ops receive the
>>> mask and handle it, to be done in the future.
>>>
>>> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
>>> ---
>>>  drivers/of/device.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/of/device.c b/drivers/of/device.c
>>> index c17c19d..c2ae6bb 100644
>>> --- a/drivers/of/device.c
>>> +++ b/drivers/of/device.c
>>> @@ -107,7 +107,7 @@ void of_dma_configure(struct device *dev, struct device_node *np)
>>>      ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
>>>      if (ret < 0) {
>>>              dma_addr = offset = 0;
>>> -            size = dev->coherent_dma_mask + 1;
>>> +            size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
>>>      } else {
>>>              offset = PFN_DOWN(paddr - dma_addr);
>>>              dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
>>>
>>
>> NACK.
>>
>> Passing an invalid size to arch_setup_dma_ops() is only part of the problem.
>> size is also used in of_dma_configure() before calling arch_setup_dma_ops():
>>
>>         dev->coherent_dma_mask = min(dev->coherent_dma_mask,
>>                                      DMA_BIT_MASK(ilog2(dma_addr + size)));
>>         *dev->dma_mask = min((*dev->dma_mask),
>>                              DMA_BIT_MASK(ilog2(dma_addr + size)));
>>
>> which would be incorrect for size == 0xffffffffffffffffULL when
>> dma_addr != 0.  So the proposed fix really is not papering over
>> the base problem very well.
>
> I'm not sure I agree there. Granted, there exist many more problematic
> aspects than are dealt with here (I've got more patches cooking to sort
> out some of the other issues we have with dma-ranges), but considering
> size specifically:
>
> - It is not possible to explicitly specify a range with a size of 2^64
> in DT. If someone does specify a size of 0, they've done a silly thing
> and should not be surprised that it ends badly.

And because of this, we allow ~0 (both 32 and 64 bit) in DT dma-ranges
and fix these up as 2^32 and 2^64 sizes.

Rob

^ permalink raw reply

* [PATCH] [media] imx: csi: retain current field order and colorimetry setting as default
From: Philipp Zabel @ 2017-04-06 13:55 UTC (permalink / raw)
  To: Steve Longerbeam
  Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A, mark.rutland-5wv7dgnIgG8,
	shawnguo-DgEjT+Ai2ygdnm+yROfE0A, kernel-bIcnvbaLZ9MEGnE8C9+IrQ,
	fabio.estevam-3arQi8VN3Tc, linux-I+IVW8TIWO2tmTQ+vhA3Yw,
	mchehab-DgEjT+Ai2ygdnm+yROfE0A, hverkuil-qWit8jRvyhVmR6Xm/wNWPw,
	nick-gcszYUEDH4VrovVCs/uTlw, markus.heiser-O6JHGLzbNUwb1SvskN2V4Q,
	laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw,
	bparrot-l0cyMroinI0, geert-Td1EMuHUCqxL1ZNQvxDV9g,
	arnd-r2nGTMty4D4, sudipm.mukherjee-Re5JQEeQqe8AvxtiuMwx3w,
	minghsiu.tsai-NuS5LvNUpcJWk0Htik3J/w,
	tiffany.lin-NuS5LvNUpcJWk0Htik3J/w,
	jean-christophe.trotin-qxv4g6HH51o,
	horms+renesas-/R6kz+dDXgpPR4JQBCEnsQ,
	niklas.soderlund+renesas-1zkq55x86MTxsAP9Fp7wbw,
	robert.jarzmik-GANU6spQydw, songjun.wu-UWL1GkI3JZL3oGB3hsPCZA,
	andrew-ct.chen-NuS5LvNUpcJWk0Htik3J/w,
	gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r,
	shuah-DgEjT+Ai2ygdnm+yROfE0A, sakari.ailus-VuQAYsv1563Yd54FQh9/CA,
	pavel-+ZI9xUNit7I, devicetree-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	linux-media-u79uwXL29TY76Z2rM5mHXA
In-Reply-To: <1490661656-10318-22-git-send-email-steve_longerbeam-nmGgyN9QBj3QT0dZR+AlfA@public.gmane.org>

If the the field order is set to ANY in set_fmt, choose the currently
set field order. If the colorspace is set to DEFAULT, choose the current
colorspace.  If any of xfer_func, ycbcr_enc or quantization are set to
DEFAULT, either choose the current setting, or the default setting for the
new colorspace, if non-DEFAULT colorspace was given.

This allows to let field order and colorimetry settings be propagated
from upstream by calling media-ctl on the upstream entity source pad,
and then call media-ctl on the sink pad to manually set the input frame
interval, without changing the already set field order and colorimetry
information.

Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
This is based on imx-media-staging-md-v14, and it is supposed to allow
configuring the pipeline with media-ctl like this:

1) media-ctl --set-v4l2 "'tc358743 1-000f':0[fmt:UYVY8_1X16/1920x1080]"
2) media-ctl --set-v4l2 "'imx6-mipi-csi2':1[fmt:UYVY8_1X16/1920x108]"
3) media-ctl --set-v4l2 "'ipu1_csi0_mux':2[fmt:UYVY8_1X16/1920x1080]"
4) media-ctl --set-v4l2 "'ipu1_csi0':0[fmt:UYVY8_1X16/1920x1080@1/60]"
5) media-ctl --set-v4l2 "'ipu1_csi0':2[fmt:AYUV32/1920x1080@1/30]"

Without having step 4) overwrite the colorspace and field order set on
'ipu1_csi0':0 by the propagation in step 3).
---
 drivers/staging/media/imx/imx-media-csi.c | 34 +++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
index 64dc454f6b371..d94ce1de2bf05 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c
@@ -1325,6 +1325,40 @@ static int csi_set_fmt(struct v4l2_subdev *sd,
 	csi_try_fmt(priv, sensor, cfg, sdformat, crop, compose, &cc);
 
 	fmt = __csi_get_fmt(priv, cfg, sdformat->pad, sdformat->which);
+
+	/* Retain current field setting as default */
+	if (sdformat->format.field == V4L2_FIELD_ANY)
+		sdformat->format.field = fmt->field;
+
+	/* Retain current colorspace setting as default */
+	if (sdformat->format.colorspace == V4L2_COLORSPACE_DEFAULT) {
+		sdformat->format.colorspace = fmt->colorspace;
+		if (sdformat->format.xfer_func == V4L2_XFER_FUNC_DEFAULT)
+			sdformat->format.xfer_func = fmt->xfer_func;
+		if (sdformat->format.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT)
+			sdformat->format.ycbcr_enc = fmt->ycbcr_enc;
+		if (sdformat->format.quantization == V4L2_QUANTIZATION_DEFAULT)
+			sdformat->format.quantization = fmt->quantization;
+	} else {
+		if (sdformat->format.xfer_func == V4L2_XFER_FUNC_DEFAULT) {
+			sdformat->format.xfer_func =
+				V4L2_MAP_XFER_FUNC_DEFAULT(
+						sdformat->format.colorspace);
+		}
+		if (sdformat->format.ycbcr_enc == V4L2_YCBCR_ENC_DEFAULT) {
+			sdformat->format.ycbcr_enc =
+				V4L2_MAP_YCBCR_ENC_DEFAULT(
+						sdformat->format.colorspace);
+		}
+		if (sdformat->format.quantization == V4L2_QUANTIZATION_DEFAULT) {
+			sdformat->format.quantization =
+				V4L2_MAP_QUANTIZATION_DEFAULT(
+						cc->cs != IPUV3_COLORSPACE_YUV,
+						sdformat->format.colorspace,
+						sdformat->format.ycbcr_enc);
+		}
+	}
+
 	*fmt = sdformat->format;
 
 	if (sdformat->pad == CSI_SINK_PAD) {
-- 
2.11.0


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^ permalink raw reply related

* [PATCH 1/1] gpio: core: Decouple open drain/source flag with active low/high
From: Laxman Dewangan @ 2017-04-06 13:35 UTC (permalink / raw)
  To: linus.walleij, gnurou, robh+dt
  Cc: mark.rutland, frowand.list, linux-gpio, linux-kernel, devicetree,
	Laxman Dewangan

Currently, the GPIO interface is said to Open Drain if it is Single
Ended and active LOW. Similarly, it is said as Open Source if it is
Single Ended and active HIGH.

The active HIGH/LOW is used in the interface for setting the pin
state to HIGH or LOW when enabling/disabling the interface.

In Open Drain interface, pin is set to HIGH by putting pin in
high impedance and LOW by driving to the LOW.

In Open Source interface, pin is set to HIGH by driving pin to
HIGH and set to LOW by putting pin in high impedance.

With above, the Open Drain/Source is unrelated to the active LOW/HIGH
in interface. There is interface where the enable/disable of interface
is ether active LOW or HIGH but it is Open Drain type.

Hence decouple the Open Drain with Single Ended + Active LOW and
Open Source with Single Ended + Active HIGH.

Adding different flag for the Open Drain/Open Source which is valid
only when Single ended flag is enabled.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/gpio/gpiolib-of.c       |  2 +-
 drivers/gpio/gpiolib.c          |  4 +++-
 include/dt-bindings/gpio/gpio.h | 12 ++++++++----
 include/linux/of_gpio.h         |  1 +
 4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 975b9f6..b13b7c7 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -147,7 +147,7 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 		*flags |= GPIO_ACTIVE_LOW;
 
 	if (of_flags & OF_GPIO_SINGLE_ENDED) {
-		if (of_flags & OF_GPIO_ACTIVE_LOW)
+		if (of_flags & OF_GPIO_OPEN_DRAIN)
 			*flags |= GPIO_OPEN_DRAIN;
 		else
 			*flags |= GPIO_OPEN_SOURCE;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 4aa1e78..c22e572 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3333,6 +3333,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 	unsigned long lflags = 0;
 	bool active_low = false;
 	bool single_ended = false;
+	bool open_drain = false;
 	int ret;
 
 	if (!fwnode)
@@ -3346,6 +3347,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 		if (!IS_ERR(desc)) {
 			active_low = flags & OF_GPIO_ACTIVE_LOW;
 			single_ended = flags & OF_GPIO_SINGLE_ENDED;
+			open_drain = flags & OF_GPIO_OPEN_DRAIN;
 		}
 	} else if (is_acpi_node(fwnode)) {
 		struct acpi_gpio_info info;
@@ -3366,7 +3368,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
 		lflags |= GPIO_ACTIVE_LOW;
 
 	if (single_ended) {
-		if (active_low)
+		if (open_drain)
 			lflags |= GPIO_OPEN_DRAIN;
 		else
 			lflags |= GPIO_OPEN_SOURCE;
diff --git a/include/dt-bindings/gpio/gpio.h b/include/dt-bindings/gpio/gpio.h
index c673d2c..b4f54da 100644
--- a/include/dt-bindings/gpio/gpio.h
+++ b/include/dt-bindings/gpio/gpio.h
@@ -17,11 +17,15 @@
 #define GPIO_PUSH_PULL 0
 #define GPIO_SINGLE_ENDED 2
 
+/* Bit 2 express Open drain or open source */
+#define GPIO_LINE_OPEN_SOURCE 0
+#define GPIO_LINE_OPEN_DRAIN 4
+
 /*
- * Open Drain/Collector is the combination of single-ended active low,
- * Open Source/Emitter is the combination of single-ended active high.
+ * Open Drain/Collector is the combination of single-ended open drain interface.
+ * Open Source/Emitter is the combination of single-ended open source interface.
  */
-#define GPIO_OPEN_DRAIN (GPIO_SINGLE_ENDED | GPIO_ACTIVE_LOW)
-#define GPIO_OPEN_SOURCE (GPIO_SINGLE_ENDED | GPIO_ACTIVE_HIGH)
+#define GPIO_OPEN_DRAIN (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_DRAIN)
+#define GPIO_OPEN_SOURCE (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_SOURCE)
 
 #endif
diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index 3f87ea5..1e089d5 100644
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -30,6 +30,7 @@ struct device_node;
 enum of_gpio_flags {
 	OF_GPIO_ACTIVE_LOW = 0x1,
 	OF_GPIO_SINGLE_ENDED = 0x2,
+	OF_GPIO_OPEN_DRAIN = 0x4,
 };
 
 #ifdef CONFIG_OF_GPIO
-- 
2.1.4


^ permalink raw reply related

* [PATCH v6 8/8] arm64: dts: qcom: msm8916: Add debug unit
From: Leo Yan @ 2017-04-06 13:31 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd, linux-doc,
	linux-kernel, devicetree, linux-arm-kernel, linux-arm-msm,
	linux-soc, Mike Leach, Sudeep Holla
  Cc: Leo Yan
In-Reply-To: <1491485461-22800-1-git-send-email-leo.yan@linaro.org>

Add debug unit on Qualcomm msm8916 based platforms, including the
DragonBoard 410c board.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 arch/arm64/boot/dts/qcom/msm8916.dtsi | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/msm8916.dtsi b/arch/arm64/boot/dts/qcom/msm8916.dtsi
index 68a8e67..3af814b 100644
--- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
@@ -1104,6 +1104,38 @@
 			};
 		};
 
+		debug@850000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0x850000 0x1000>;
+			clocks = <&rpmcc RPM_QDSS_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&CPU0>;
+		};
+
+		debug@852000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0x852000 0x1000>;
+			clocks = <&rpmcc RPM_QDSS_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&CPU1>;
+		};
+
+		debug@854000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0x854000 0x1000>;
+			clocks = <&rpmcc RPM_QDSS_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&CPU2>;
+		};
+
+		debug@856000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0x856000 0x1000>;
+			clocks = <&rpmcc RPM_QDSS_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&CPU3>;
+		};
+
 		etm@85c000 {
 			compatible = "arm,coresight-etm4x", "arm,primecell";
 			reg = <0x85c000 0x1000>;
-- 
2.7.4

^ permalink raw reply related

* [PATCH v6 7/8] arm64: dts: hi6220: register debug module
From: Leo Yan @ 2017-04-06 13:31 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd, linux-doc,
	linux-kernel, devicetree, linux-arm-kernel, linux-arm-msm,
	linux-soc, Mike Leach, Sudeep Holla
  Cc: Leo Yan
In-Reply-To: <1491485461-22800-1-git-send-email-leo.yan@linaro.org>

Bind debug module driver for Hi6220.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 arch/arm64/boot/dts/hisilicon/hi6220.dtsi | 64 +++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/arch/arm64/boot/dts/hisilicon/hi6220.dtsi b/arch/arm64/boot/dts/hisilicon/hi6220.dtsi
index 470461d..467aa15 100644
--- a/arch/arm64/boot/dts/hisilicon/hi6220.dtsi
+++ b/arch/arm64/boot/dts/hisilicon/hi6220.dtsi
@@ -913,5 +913,69 @@
 				};
 			};
 		};
+
+		debug@f6590000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0 0xf6590000 0 0x1000>;
+			clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&cpu0>;
+		};
+
+		debug@f6592000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0 0xf6592000 0 0x1000>;
+			clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&cpu1>;
+		};
+
+		debug@f6594000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0 0xf6594000 0 0x1000>;
+			clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&cpu2>;
+		};
+
+		debug@f6596000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0 0xf6596000 0 0x1000>;
+			clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&cpu3>;
+		};
+
+		debug@f65d0000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0 0xf65d0000 0 0x1000>;
+			clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&cpu4>;
+		};
+
+		debug@f65d2000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0 0xf65d2000 0 0x1000>;
+			clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&cpu5>;
+		};
+
+		debug@f65d4000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0 0xf65d4000 0 0x1000>;
+			clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&cpu6>;
+		};
+
+		debug@f65d6000 {
+			compatible = "arm,coresight-cpu-debug","arm,primecell";
+			reg = <0 0xf65d6000 0 0x1000>;
+			clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+			clock-names = "apb_pclk";
+			cpu = <&cpu7>;
+		};
 	};
 };
-- 
2.7.4


^ permalink raw reply related

* [PATCH v6 6/8] coresight: add support for CPU debug module
From: Leo Yan @ 2017-04-06 13:30 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd,
	linux-doc-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	linux-arm-msm-u79uwXL29TY76Z2rM5mHXA,
	linux-soc-u79uwXL29TY76Z2rM5mHXA, Mike Leach, Sudeep Holla
  Cc: Leo Yan
In-Reply-To: <1491485461-22800-1-git-send-email-leo.yan-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

Coresight includes debug module and usually the module connects with CPU
debug logic. ARMv8 architecture reference manual (ARM DDI 0487A.k) has
description for related info in "Part H: External Debug".

Chapter H7 "The Sample-based Profiling Extension" introduces several
sampling registers, e.g. we can check program counter value with
combined CPU exception level, secure state, etc. So this is helpful for
analysis CPU lockup scenarios, e.g. if one CPU has run into infinite
loop with IRQ disabled. In this case the CPU cannot switch context and
handle any interrupt (including IPIs), as the result it cannot handle
SMP call for stack dump.

This patch is to enable coresight debug module, so firstly this driver
is to bind apb clock for debug module and this is to ensure the debug
module can be accessed from program or external debugger. And the driver
uses sample-based registers for debug purpose, e.g. when system triggers
panic, the driver will dump program counter and combined context
registers (EDCIDSR, EDVIDSR); by parsing context registers so can
quickly get to know CPU secure state, exception level, etc.

Some of the debug module registers are located in CPU power domain, so
this requires the CPU power domain stays on when access related debug
registers, but the power management for CPU power domain is quite
dependent on SoC integration for power management. For the platforms
which with sane power controller implementations, this driver follows
the method to set EDPRCR to try to pull the CPU out of low power state
and then set 'no power down request' bit so the CPU has no chance to
lose power.

If the SoC has not followed up this design well for power management
controller, the user should use the command line parameter or sysfs
to constrain all or partial idle states to ensure the CPU power
domain is enabled and access coresight CPU debug component safely.

Signed-off-by: Leo Yan <leo.yan-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 drivers/hwtracing/coresight/Kconfig               |  14 +
 drivers/hwtracing/coresight/Makefile              |   1 +
 drivers/hwtracing/coresight/coresight-cpu-debug.c | 667 ++++++++++++++++++++++
 3 files changed, 682 insertions(+)
 create mode 100644 drivers/hwtracing/coresight/coresight-cpu-debug.c

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 130cb21..8d55d6d 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -89,4 +89,18 @@ config CORESIGHT_STM
 	  logging useful software events or data coming from various entities
 	  in the system, possibly running different OSs
 
+config CORESIGHT_CPU_DEBUG
+	tristate "CoreSight CPU Debug driver"
+	depends on ARM || ARM64
+	depends on DEBUG_FS
+	help
+	  This driver provides support for coresight debugging module. This
+	  is primarily used to dump sample-based profiling registers when
+	  system triggers panic, the driver will parse context registers so
+	  can quickly get to know program counter (PC), secure state,
+	  exception level, etc. Before use debugging functionality, platform
+	  needs to ensure the clock domain and power domain are enabled
+	  properly, please refer Documentation/trace/coresight-cpu-debug.txt
+	  for detailed description and the example for usage.
+
 endif
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index af480d9..433d590 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \
 					coresight-etm4x-sysfs.o
 obj-$(CONFIG_CORESIGHT_QCOM_REPLICATOR) += coresight-replicator-qcom.o
 obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
+obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c
new file mode 100644
index 0000000..8470e31
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c
@@ -0,0 +1,667 @@
+/*
+ * Copyright (c) 2017 Linaro Limited. All rights reserved.
+ *
+ * Author: Leo Yan <leo.yan-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <linux/amba/bus.h>
+#include <linux/coresight.h>
+#include <linux/cpu.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/pm_qos.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include "coresight-priv.h"
+
+#define EDPCSR				0x0A0
+#define EDCIDSR				0x0A4
+#define EDVIDSR				0x0A8
+#define EDPCSR_HI			0x0AC
+#define EDOSLAR				0x300
+#define EDPRCR				0x310
+#define EDPRSR				0x314
+#define EDDEVID1			0xFC4
+#define EDDEVID				0xFC8
+
+#define EDPCSR_PROHIBITED		0xFFFFFFFF
+
+/* bits definition for EDPCSR */
+#define EDPCSR_THUMB			BIT(0)
+#define EDPCSR_ARM_INST_MASK		GENMASK(31, 2)
+#define EDPCSR_THUMB_INST_MASK		GENMASK(31, 1)
+
+/* bits definition for EDPRCR */
+#define EDPRCR_COREPURQ			BIT(3)
+#define EDPRCR_CORENPDRQ		BIT(0)
+
+/* bits definition for EDPRSR */
+#define EDPRSR_DLK			BIT(6)
+#define EDPRSR_PU			BIT(0)
+
+/* bits definition for EDVIDSR */
+#define EDVIDSR_NS			BIT(31)
+#define EDVIDSR_E2			BIT(30)
+#define EDVIDSR_E3			BIT(29)
+#define EDVIDSR_HV			BIT(28)
+#define EDVIDSR_VMID			GENMASK(7, 0)
+
+/*
+ * bits definition for EDDEVID1:PSCROffset
+ *
+ * NOTE: armv8 and armv7 have different definition for the register,
+ * so consolidate the bits definition as below:
+ *
+ * 0b0000 - Sample offset applies based on the instruction state, we
+ *          rely on EDDEVID to check if EDPCSR is implemented or not
+ * 0b0001 - No offset applies.
+ * 0b0010 - No offset applies, but do not use in AArch32 mode
+ *
+ */
+#define EDDEVID1_PCSR_OFFSET_MASK	GENMASK(3, 0)
+#define EDDEVID1_PCSR_OFFSET_INS_SET	(0x0)
+#define EDDEVID1_PCSR_NO_OFFSET_DIS_AARCH32	(0x2)
+
+/* bits definition for EDDEVID */
+#define EDDEVID_PCSAMPLE_MODE		GENMASK(3, 0)
+#define EDDEVID_IMPL_EDPCSR		(0x1)
+#define EDDEVID_IMPL_EDPCSR_EDCIDSR	(0x2)
+#define EDDEVID_IMPL_FULL		(0x3)
+
+#define DEBUG_WAIT_SLEEP		1000
+#define DEBUG_WAIT_TIMEOUT		32000
+
+struct debug_drvdata {
+	void __iomem	*base;
+	struct device	*dev;
+	int		cpu;
+
+	bool		edpcsr_present;
+	bool		edcidsr_present;
+	bool		edvidsr_present;
+	bool		pc_has_offset;
+
+	u32		edpcsr;
+	u32		edpcsr_hi;
+	u32		edprsr;
+	u32		edvidsr;
+	u32		edcidsr;
+};
+
+static DEFINE_MUTEX(debug_lock);
+static DEFINE_PER_CPU(struct debug_drvdata *, debug_drvdata);
+static int debug_count;
+static struct dentry *debug_debugfs_dir;
+
+static bool debug_enable;
+module_param_named(enable, debug_enable, bool, 0600);
+MODULE_PARM_DESC(enable, "Knob to enable debug functionality "
+		 "(default is 0, which means is disabled by default)");
+
+static void debug_os_unlock(struct debug_drvdata *drvdata)
+{
+	/* Unlocks the debug registers */
+	writel_relaxed(0x0, drvdata->base + EDOSLAR);
+	wmb();
+}
+
+/*
+ * According to ARM DDI 0487A.k, before access external debug
+ * registers should firstly check the access permission; if any
+ * below condition has been met then cannot access debug
+ * registers to avoid lockup issue:
+ *
+ * - CPU power domain is powered off;
+ * - The OS Double Lock is locked;
+ *
+ * By checking EDPRSR can get to know if meet these conditions.
+ */
+static bool debug_access_permitted(struct debug_drvdata *drvdata)
+{
+	/* CPU is powered off */
+	if (!(drvdata->edprsr & EDPRSR_PU))
+		return false;
+
+	/* The OS Double Lock is locked */
+	if (drvdata->edprsr & EDPRSR_DLK)
+		return false;
+
+	return true;
+}
+
+static void debug_force_cpu_powered_up(struct debug_drvdata *drvdata)
+{
+	bool retried = false;
+	u32 edprcr;
+
+try_again:
+
+	/*
+	 * Send request to power management controller and assert
+	 * DBGPWRUPREQ signal; if power management controller has
+	 * sane implementation, it should enable CPU power domain
+	 * in case CPU is in low power state.
+	 */
+	edprcr = readl_relaxed(drvdata->base + EDPRCR);
+	edprcr |= EDPRCR_COREPURQ;
+	writel_relaxed(edprcr, drvdata->base + EDPRCR);
+
+	/* Wait for CPU to be powered up (timeout~=32ms) */
+	if (readx_poll_timeout_atomic(readl_relaxed, drvdata->base + EDPRSR,
+			drvdata->edprsr, (drvdata->edprsr & EDPRSR_PU),
+			DEBUG_WAIT_SLEEP, DEBUG_WAIT_TIMEOUT)) {
+		/*
+		 * Unfortunately the CPU cannot be powered up, so return
+		 * back and later has no permission to access other
+		 * registers. For this case, should disable CPU low power
+		 * states to ensure CPU power domain is enabled!
+		 */
+		pr_err("%s: power up request for CPU%d failed\n",
+			__func__, drvdata->cpu);
+		return;
+	}
+
+	/*
+	 * At this point the CPU is powered up, so set the no powerdown
+	 * request bit so we don't lose power and emulate power down.
+	 */
+	edprcr = readl_relaxed(drvdata->base + EDPRCR);
+	edprcr |= EDPRCR_COREPURQ | EDPRCR_CORENPDRQ;
+	writel_relaxed(edprcr, drvdata->base + EDPRCR);
+
+	drvdata->edprsr = readl_relaxed(drvdata->base + EDPRSR);
+
+	/* Bail out if CPU is powered up */
+	if (likely(drvdata->edprsr & EDPRSR_PU))
+		return;
+
+	/*
+	 * Handle race condition if CPU has been waken up but it sleeps
+	 * again if EDPRCR_CORENPDRQ has been flipped, so try to run
+	 * waken flow one more time.
+	 */
+	if (!retried) {
+		retried = true;
+		goto try_again;
+	}
+}
+
+static void debug_read_regs(struct debug_drvdata *drvdata)
+{
+	u32 save_edprcr;
+
+	CS_UNLOCK(drvdata->base);
+
+	/* Unlock os lock */
+	debug_os_unlock(drvdata);
+
+	/* Save EDPRCR register */
+	save_edprcr = readl_relaxed(drvdata->base + EDPRCR);
+
+	/*
+	 * Ensure CPU power domain is enabled to let registers
+	 * are accessiable.
+	 */
+	debug_force_cpu_powered_up(drvdata);
+
+	if (!debug_access_permitted(drvdata))
+		goto out;
+
+	drvdata->edpcsr = readl_relaxed(drvdata->base + EDPCSR);
+
+	/*
+	 * As described in ARM DDI 0487A.k, if the processing
+	 * element (PE) is in debug state, or sample-based
+	 * profiling is prohibited, EDPCSR reads as 0xFFFFFFFF;
+	 * EDCIDSR, EDVIDSR and EDPCSR_HI registers also become
+	 * UNKNOWN state. So directly bail out for this case.
+	 */
+	if (drvdata->edpcsr == EDPCSR_PROHIBITED)
+		goto out;
+
+	/*
+	 * A read of the EDPCSR normally has the side-effect of
+	 * indirectly writing to EDCIDSR, EDVIDSR and EDPCSR_HI;
+	 * at this point it's safe to read value from them.
+	 */
+	if (IS_ENABLED(CONFIG_64BIT))
+		drvdata->edpcsr_hi = readl_relaxed(drvdata->base + EDPCSR_HI);
+
+	if (drvdata->edcidsr_present)
+		drvdata->edcidsr = readl_relaxed(drvdata->base + EDCIDSR);
+
+	if (drvdata->edvidsr_present)
+		drvdata->edvidsr = readl_relaxed(drvdata->base + EDVIDSR);
+
+out:
+	/* Restore EDPRCR register */
+	writel_relaxed(save_edprcr, drvdata->base + EDPRCR);
+
+	CS_LOCK(drvdata->base);
+}
+
+static unsigned long debug_adjust_pc(struct debug_drvdata *drvdata)
+{
+	unsigned long arm_inst_offset = 0, thumb_inst_offset = 0;
+	unsigned long pc;
+
+	if (IS_ENABLED(CONFIG_64BIT))
+		return (unsigned long)drvdata->edpcsr_hi << 32 |
+		       (unsigned long)drvdata->edpcsr;
+
+	pc = (unsigned long)drvdata->edpcsr;
+
+	if (drvdata->pc_has_offset) {
+		arm_inst_offset = 8;
+		thumb_inst_offset = 4;
+	}
+
+	/* Handle thumb instruction */
+	if (pc & EDPCSR_THUMB) {
+		pc = (pc & EDPCSR_THUMB_INST_MASK) - thumb_inst_offset;
+		return pc;
+	}
+
+	/*
+	 * Handle arm instruction offset, if the arm instruction
+	 * is not 4 byte alignment then it's possible the case
+	 * for implementation defined; keep original value for this
+	 * case and print info for notice.
+	 */
+	if (pc & BIT(1))
+		pr_emerg("Instruction offset is implementation defined\n");
+	else
+		pc = (pc & EDPCSR_ARM_INST_MASK) - arm_inst_offset;
+
+	return pc;
+}
+
+static void debug_dump_regs(struct debug_drvdata *drvdata)
+{
+	unsigned long pc;
+
+	pr_emerg("\tEDPRSR:  %08x (Power:%s DLK:%s)\n", drvdata->edprsr,
+		 drvdata->edprsr & EDPRSR_PU ? "On" : "Off",
+		 drvdata->edprsr & EDPRSR_DLK ? "Lock" : "Unlock");
+
+	if (!debug_access_permitted(drvdata)) {
+		pr_emerg("No permission to access debug registers!\n");
+		return;
+	}
+
+	if (drvdata->edpcsr == EDPCSR_PROHIBITED) {
+		pr_emerg("CPU is in Debug state or profiling is prohibited!\n");
+		return;
+	}
+
+	pc = debug_adjust_pc(drvdata);
+	pr_emerg("\tEDPCSR:  [<%p>] %pS\n", (void *)pc, (void *)pc);
+
+	if (drvdata->edcidsr_present)
+		pr_emerg("\tEDCIDSR: %08x\n", drvdata->edcidsr);
+
+	if (drvdata->edvidsr_present)
+		pr_emerg("\tEDVIDSR: %08x (State:%s Mode:%s Width:%dbits VMID:%x)\n",
+			 drvdata->edvidsr,
+			 drvdata->edvidsr & EDVIDSR_NS ? "Non-secure" : "Secure",
+			 drvdata->edvidsr & EDVIDSR_E3 ? "EL3" :
+				(drvdata->edvidsr & EDVIDSR_E2 ? "EL2" : "EL1/0"),
+			 drvdata->edvidsr & EDVIDSR_HV ? 64 : 32,
+			 drvdata->edvidsr & (u32)EDVIDSR_VMID);
+}
+
+static void debug_init_arch_data(void *info)
+{
+	struct debug_drvdata *drvdata = info;
+	u32 mode, pcsr_offset;
+	u32 eddevid, eddevid1;
+
+	CS_UNLOCK(drvdata->base);
+
+	/* Read device info */
+	eddevid  = readl_relaxed(drvdata->base + EDDEVID);
+	eddevid1 = readl_relaxed(drvdata->base + EDDEVID1);
+
+	CS_LOCK(drvdata->base);
+
+	/* Parse implementation feature */
+	mode = eddevid & EDDEVID_PCSAMPLE_MODE;
+	pcsr_offset = eddevid1 & EDDEVID1_PCSR_OFFSET_MASK;
+
+	drvdata->edpcsr_present  = false;
+	drvdata->edcidsr_present = false;
+	drvdata->edvidsr_present = false;
+	drvdata->pc_has_offset   = false;
+
+	switch (mode) {
+	case EDDEVID_IMPL_FULL:
+		drvdata->edvidsr_present = true;
+		/* Fall through */
+	case EDDEVID_IMPL_EDPCSR_EDCIDSR:
+		drvdata->edcidsr_present = true;
+		/* Fall through */
+	case EDDEVID_IMPL_EDPCSR:
+		/*
+		 * In ARM DDI 0487A.k, the EDDEVID1.PCSROffset is used to
+		 * define if has the offset for PC sampling value; if read
+		 * back EDDEVID1.PCSROffset == 0x2, then this means the debug
+		 * module does not sample the instruction set state when
+		 * armv8 CPU in AArch32 state.
+		 */
+		drvdata->edpcsr_present = (IS_ENABLED(CONFIG_64BIT) ||
+			(pcsr_offset != EDDEVID1_PCSR_NO_OFFSET_DIS_AARCH32));
+
+		drvdata->pc_has_offset =
+			(pcsr_offset == EDDEVID1_PCSR_OFFSET_INS_SET);
+		break;
+	default:
+		break;
+	}
+}
+
+/*
+ * Dump out information on panic.
+ */
+static int debug_notifier_call(struct notifier_block *self,
+			       unsigned long v, void *p)
+{
+	int cpu;
+	struct debug_drvdata *drvdata;
+
+	pr_emerg("ARM external debug module:\n");
+
+	for_each_possible_cpu(cpu) {
+		drvdata = per_cpu(debug_drvdata, cpu);
+		if (!drvdata)
+			continue;
+
+		pr_emerg("CPU[%d]:\n", drvdata->cpu);
+
+		debug_read_regs(drvdata);
+		debug_dump_regs(drvdata);
+	}
+
+	return 0;
+}
+
+static struct notifier_block debug_notifier = {
+	.notifier_call = debug_notifier_call,
+};
+
+static int debug_enable_func(void)
+{
+	struct debug_drvdata *drvdata;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		drvdata = per_cpu(debug_drvdata, cpu);
+		if (!drvdata)
+			continue;
+
+		pm_runtime_get_sync(drvdata->dev);
+	}
+
+	return atomic_notifier_chain_register(&panic_notifier_list,
+					      &debug_notifier);
+}
+
+static int debug_disable_func(void)
+{
+	struct debug_drvdata *drvdata;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		drvdata = per_cpu(debug_drvdata, cpu);
+		if (!drvdata)
+			continue;
+
+		pm_runtime_put(drvdata->dev);
+	}
+
+	return atomic_notifier_chain_unregister(&panic_notifier_list,
+						&debug_notifier);
+}
+
+static ssize_t debug_func_knob_write(struct file *f,
+		const char __user *buf, size_t count, loff_t *ppos)
+{
+	u8 val;
+	int ret;
+
+	ret = kstrtou8_from_user(buf, count, 2, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&debug_lock);
+
+	if (val == debug_enable)
+		goto out;
+
+	if (val)
+		ret = debug_enable_func();
+	else
+		ret = debug_disable_func();
+
+	if (ret) {
+		pr_err("%s: unable to %s debug function: %d\n",
+		       __func__, val ? "enable" : "disable", ret);
+		goto err;
+	}
+
+	debug_enable = val;
+out:
+	ret = count;
+err:
+	mutex_unlock(&debug_lock);
+	return ret;
+}
+
+static ssize_t debug_func_knob_read(struct file *f,
+		char __user *ubuf, size_t count, loff_t *ppos)
+{
+	ssize_t ret;
+	char buf[2];
+
+	mutex_lock(&debug_lock);
+
+	buf[0] = '0' + debug_enable;
+	buf[1] = '\n';
+	ret = simple_read_from_buffer(ubuf, count, ppos, buf, sizeof(buf));
+
+	mutex_unlock(&debug_lock);
+	return ret;
+}
+
+static const struct file_operations debug_func_knob_fops = {
+	.open	= simple_open,
+	.read	= debug_func_knob_read,
+	.write	= debug_func_knob_write,
+};
+
+static int debug_func_init(void)
+{
+	struct dentry *file;
+	int ret;
+
+	/* Create debugfs node */
+	debug_debugfs_dir = debugfs_create_dir("coresight_cpu_debug", NULL);
+	if (!debug_debugfs_dir) {
+		pr_err("%s: unable to create debugfs directory\n", __func__);
+		return -ENOMEM;
+	}
+
+	file = debugfs_create_file("enable", S_IRUGO | S_IWUSR,
+			debug_debugfs_dir, NULL, &debug_func_knob_fops);
+	if (!file) {
+		pr_err("%s: unable to create enable knob file\n", __func__);
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	/* Use sysfs node to enable functionality */
+	if (!debug_enable)
+		return 0;
+
+	/* Register function to be called for panic */
+	ret = atomic_notifier_chain_register(&panic_notifier_list,
+					     &debug_notifier);
+	if (ret) {
+		pr_err("%s: unable to register notifier: %d\n",
+		       __func__, ret);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	debugfs_remove_recursive(debug_debugfs_dir);
+	return ret;
+}
+
+static void debug_func_exit(void)
+{
+	debugfs_remove_recursive(debug_debugfs_dir);
+
+	/* Unregister panic notifier callback */
+	if (debug_enable)
+		atomic_notifier_chain_unregister(&panic_notifier_list,
+						 &debug_notifier);
+}
+
+static int debug_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	void __iomem *base;
+	struct device *dev = &adev->dev;
+	struct debug_drvdata *drvdata;
+	struct resource *res = &adev->res;
+	struct device_node *np = adev->dev.of_node;
+	int ret;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->cpu = np ? of_coresight_get_cpu(np) : 0;
+	if (per_cpu(debug_drvdata, drvdata->cpu)) {
+		dev_err(dev, "CPU%d drvdata has been initialized\n",
+			drvdata->cpu);
+		return -EBUSY;
+	}
+
+	drvdata->dev = &adev->dev;
+	amba_set_drvdata(adev, drvdata);
+
+	/* Validity for the resource is already checked by the AMBA core */
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	drvdata->base = base;
+
+	get_online_cpus();
+	per_cpu(debug_drvdata, drvdata->cpu) = drvdata;
+	ret = smp_call_function_single(drvdata->cpu,
+				debug_init_arch_data, drvdata, 1);
+	put_online_cpus();
+
+	if (ret) {
+		dev_err(dev, "CPU%d debug arch init failed\n", drvdata->cpu);
+		goto err;
+	}
+
+	if (!drvdata->edpcsr_present) {
+		dev_err(dev, "CPU%d sample-based profiling isn't implemented\n",
+			drvdata->cpu);
+		ret = -ENXIO;
+		goto err;
+	}
+
+	if (!debug_count++) {
+		ret = debug_func_init();
+		if (ret)
+			goto err_func_init;
+	}
+
+	if (!debug_enable)
+		pm_runtime_put(dev);
+
+	dev_info(dev, "Coresight debug-CPU%d initialized\n", drvdata->cpu);
+	return 0;
+
+err_func_init:
+	debug_count--;
+err:
+	per_cpu(debug_drvdata, drvdata->cpu) = NULL;
+	return ret;
+}
+
+static int debug_remove(struct amba_device *adev)
+{
+	struct device *dev = &adev->dev;
+	struct debug_drvdata *drvdata = amba_get_drvdata(adev);
+
+	per_cpu(debug_drvdata, drvdata->cpu) = NULL;
+
+	if (debug_enable)
+		pm_runtime_put(dev);
+
+	if (!--debug_count)
+		debug_func_exit();
+
+	return 0;
+}
+
+static struct amba_id debug_ids[] = {
+	{       /* Debug for Cortex-A53 */
+		.id	= 0x000bbd03,
+		.mask	= 0x000fffff,
+	},
+	{       /* Debug for Cortex-A57 */
+		.id	= 0x000bbd07,
+		.mask	= 0x000fffff,
+	},
+	{       /* Debug for Cortex-A72 */
+		.id	= 0x000bbd08,
+		.mask	= 0x000fffff,
+	},
+	{ 0, 0 },
+};
+
+static struct amba_driver debug_driver = {
+	.drv = {
+		.name   = "coresight-cpu-debug",
+		.suppress_bind_attrs = true,
+	},
+	.probe		= debug_probe,
+	.remove		= debug_remove,
+	.id_table	= debug_ids,
+};
+
+module_amba_driver(debug_driver);
+
+MODULE_AUTHOR("Leo Yan <leo.yan-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>");
+MODULE_DESCRIPTION("ARM Coresight CPU Debug Driver");
+MODULE_LICENSE("GPL");
-- 
2.7.4

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^ permalink raw reply related

* [PATCH v6 5/8] coresight: use const for device_node structures
From: Leo Yan @ 2017-04-06 13:30 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd, linux-doc,
	linux-kernel, devicetree, linux-arm-kernel, linux-arm-msm,
	linux-soc, Mike Leach, Sudeep Holla
  Cc: Leo Yan
In-Reply-To: <1491485461-22800-1-git-send-email-leo.yan@linaro.org>

Almost low level functions from open firmware have used const to
qualify device_node structures, so add const for device_node
parameters in of_coresight related functions.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 drivers/hwtracing/coresight/of_coresight.c | 6 +++---
 include/linux/coresight.h                  | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/of_coresight.c b/drivers/hwtracing/coresight/of_coresight.c
index 78d2399..46eec0f 100644
--- a/drivers/hwtracing/coresight/of_coresight.c
+++ b/drivers/hwtracing/coresight/of_coresight.c
@@ -52,7 +52,7 @@ of_coresight_get_endpoint_device(struct device_node *endpoint)
 			       endpoint, of_dev_node_match);
 }
 
-static void of_coresight_get_ports(struct device_node *node,
+static void of_coresight_get_ports(const struct device_node *node,
 				   int *nr_inport, int *nr_outport)
 {
 	struct device_node *ep = NULL;
@@ -101,7 +101,7 @@ static int of_coresight_alloc_memory(struct device *dev,
 	return 0;
 }
 
-int of_coresight_get_cpu(struct device_node *node)
+int of_coresight_get_cpu(const struct device_node *node)
 {
 	int cpu;
 	bool found;
@@ -128,7 +128,7 @@ int of_coresight_get_cpu(struct device_node *node)
 EXPORT_SYMBOL_GPL(of_coresight_get_cpu);
 
 struct coresight_platform_data *of_get_coresight_platform_data(
-				struct device *dev, struct device_node *node)
+			struct device *dev, const struct device_node *node)
 {
 	int i = 0, ret = 0;
 	struct coresight_platform_data *pdata;
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index bf96678..4915254 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -263,13 +263,13 @@ static inline int coresight_timeout(void __iomem *addr, u32 offset,
 #endif
 
 #ifdef CONFIG_OF
-extern int of_coresight_get_cpu(struct device_node *node);
+extern int of_coresight_get_cpu(const struct device_node *node);
 extern struct coresight_platform_data *of_get_coresight_platform_data(
-				struct device *dev, struct device_node *node);
+	struct device *dev, const struct device_node *node);
 #else
-static inline int of_coresight_get_cpu(struct device_node *node) { return 0; }
+static inline int of_coresight_get_cpu(const struct device_node *node) { return 0; }
 static inline struct coresight_platform_data *of_get_coresight_platform_data(
-	struct device *dev, struct device_node *node) { return NULL; }
+	struct device *dev, const struct device_node *node) { return NULL; }
 #endif
 
 #ifdef CONFIG_PID_NS
-- 
2.7.4


^ permalink raw reply related

* [PATCH v6 4/8] coresight: refactor with function of_coresight_get_cpu
From: Leo Yan @ 2017-04-06 13:30 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd, linux-doc,
	linux-kernel, devicetree, linux-arm-kernel, linux-arm-msm,
	linux-soc, Mike Leach, Sudeep Holla
  Cc: Leo Yan
In-Reply-To: <1491485461-22800-1-git-send-email-leo.yan@linaro.org>

This is refactor to add function of_coresight_get_cpu(), so it's used to
retrieve CPU id for coresight component. Finally can use it as a common
function for multiple places.

Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 drivers/hwtracing/coresight/of_coresight.c | 43 +++++++++++++++++++-----------
 include/linux/coresight.h                  |  2 ++
 2 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/drivers/hwtracing/coresight/of_coresight.c b/drivers/hwtracing/coresight/of_coresight.c
index 1a77280..78d2399 100644
--- a/drivers/hwtracing/coresight/of_coresight.c
+++ b/drivers/hwtracing/coresight/of_coresight.c
@@ -101,15 +101,39 @@ static int of_coresight_alloc_memory(struct device *dev,
 	return 0;
 }
 
+int of_coresight_get_cpu(struct device_node *node)
+{
+	int cpu;
+	bool found;
+	struct device_node *dn, *np;
+
+	dn = of_parse_phandle(node, "cpu", 0);
+
+	/* Affinity defaults to CPU0 */
+	if (!dn)
+		return 0;
+
+	for_each_possible_cpu(cpu) {
+		np = of_cpu_device_node_get(cpu);
+		found = (dn == np);
+		of_node_put(np);
+		if (found)
+			break;
+	}
+	of_node_put(dn);
+
+	/* Affinity to CPU0 if no cpu nodes are found */
+	return found ? cpu : 0;
+}
+EXPORT_SYMBOL_GPL(of_coresight_get_cpu);
+
 struct coresight_platform_data *of_get_coresight_platform_data(
 				struct device *dev, struct device_node *node)
 {
-	int i = 0, ret = 0, cpu;
+	int i = 0, ret = 0;
 	struct coresight_platform_data *pdata;
 	struct of_endpoint endpoint, rendpoint;
 	struct device *rdev;
-	bool found;
-	struct device_node *dn, *np;
 	struct device_node *ep = NULL;
 	struct device_node *rparent = NULL;
 	struct device_node *rport = NULL;
@@ -176,18 +200,7 @@ struct coresight_platform_data *of_get_coresight_platform_data(
 		} while (ep);
 	}
 
-	dn = of_parse_phandle(node, "cpu", 0);
-	for_each_possible_cpu(cpu) {
-		np = of_cpu_device_node_get(cpu);
-		found = (dn == np);
-		of_node_put(np);
-		if (found)
-			break;
-	}
-	of_node_put(dn);
-
-	/* Affinity to CPU0 if no cpu nodes are found */
-	pdata->cpu = found ? cpu : 0;
+	pdata->cpu = of_coresight_get_cpu(node);
 
 	return pdata;
 }
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 2a5982c..bf96678 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -263,9 +263,11 @@ static inline int coresight_timeout(void __iomem *addr, u32 offset,
 #endif
 
 #ifdef CONFIG_OF
+extern int of_coresight_get_cpu(struct device_node *node);
 extern struct coresight_platform_data *of_get_coresight_platform_data(
 				struct device *dev, struct device_node *node);
 #else
+static inline int of_coresight_get_cpu(struct device_node *node) { return 0; }
 static inline struct coresight_platform_data *of_get_coresight_platform_data(
 	struct device *dev, struct device_node *node) { return NULL; }
 #endif
-- 
2.7.4

^ permalink raw reply related

* [PATCH v6 3/8] coresight: of_get_coresight_platform_data: Add missing of_node_put
From: Leo Yan @ 2017-04-06 13:30 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd, linux-doc,
	linux-kernel, devicetree, linux-arm-kernel, linux-arm-msm,
	linux-soc, Mike Leach, Sudeep Holla
  Cc: Leo Yan
In-Reply-To: <1491485461-22800-1-git-send-email-leo.yan@linaro.org>

From: Suzuki K Poulose <suzuki.poulose@arm.com>

The of_get_coresight_platform_data iterates over the possible CPU nodes
to find a given cpu phandle. However it does not drop the reference
to the node pointer returned by the of_get_coresight_platform_data.

This patch also introduces another minor fix is to use
of_cpu_device_node_get() to replace of_get_cpu_node().

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[Leo: minor tweaks for of_get_coresight_platform_data]
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 drivers/hwtracing/coresight/of_coresight.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/of_coresight.c b/drivers/hwtracing/coresight/of_coresight.c
index 629e031..1a77280 100644
--- a/drivers/hwtracing/coresight/of_coresight.c
+++ b/drivers/hwtracing/coresight/of_coresight.c
@@ -108,7 +108,8 @@ struct coresight_platform_data *of_get_coresight_platform_data(
 	struct coresight_platform_data *pdata;
 	struct of_endpoint endpoint, rendpoint;
 	struct device *rdev;
-	struct device_node *dn;
+	bool found;
+	struct device_node *dn, *np;
 	struct device_node *ep = NULL;
 	struct device_node *rparent = NULL;
 	struct device_node *rport = NULL;
@@ -175,17 +176,19 @@ struct coresight_platform_data *of_get_coresight_platform_data(
 		} while (ep);
 	}
 
-	/* Affinity defaults to CPU0 */
-	pdata->cpu = 0;
 	dn = of_parse_phandle(node, "cpu", 0);
-	for (cpu = 0; dn && cpu < nr_cpu_ids; cpu++) {
-		if (dn == of_get_cpu_node(cpu, NULL)) {
-			pdata->cpu = cpu;
+	for_each_possible_cpu(cpu) {
+		np = of_cpu_device_node_get(cpu);
+		found = (dn == np);
+		of_node_put(np);
+		if (found)
 			break;
-		}
 	}
 	of_node_put(dn);
 
+	/* Affinity to CPU0 if no cpu nodes are found */
+	pdata->cpu = found ? cpu : 0;
+
 	return pdata;
 }
 EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);
-- 
2.7.4

^ permalink raw reply related

* [PATCH v6 2/8] doc: Add documentation for Coresight CPU debug
From: Leo Yan @ 2017-04-06 13:30 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd, linux-doc,
	linux-kernel, devicetree, linux-arm-kernel, linux-arm-msm,
	linux-soc, Mike Leach, Sudeep Holla
  Cc: Leo Yan
In-Reply-To: <1491485461-22800-1-git-send-email-leo.yan@linaro.org>

Update kernel-parameters.txt to add new parameter:
coresight_cpu_debug.enable is a knob to enable debugging at boot time.

Add detailed documentation, which contains the implementation, Mike
Leach excellent summary for "clock and power domain". At the end some
examples on how to enable the debugging functionality are provided.

Suggested-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 Documentation/admin-guide/kernel-parameters.txt |   7 +
 Documentation/trace/coresight-cpu-debug.txt     | 173 ++++++++++++++++++++++++
 2 files changed, 180 insertions(+)
 create mode 100644 Documentation/trace/coresight-cpu-debug.txt

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index facc20a..cf90146 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -650,6 +650,13 @@
 			/proc/<pid>/coredump_filter.
 			See also Documentation/filesystems/proc.txt.
 
+	coresight_cpu_debug.enable
+			[ARM,ARM64]
+			Format: <bool>
+			Enable/disable the CPU sampling based debugging.
+			0: default value, disable debugging
+			1: enable debugging at boot time
+
 	cpuidle.off=1	[CPU_IDLE]
 			disable the cpuidle sub-system
 
diff --git a/Documentation/trace/coresight-cpu-debug.txt b/Documentation/trace/coresight-cpu-debug.txt
new file mode 100644
index 0000000..e7ad05e
--- /dev/null
+++ b/Documentation/trace/coresight-cpu-debug.txt
@@ -0,0 +1,173 @@
+		Coresight CPU Debug Module
+		==========================
+
+   Author:   Leo Yan <leo.yan@linaro.org>
+   Date:     April 5th, 2017
+
+Introduction
+------------
+
+Coresight CPU debug module is defined in ARMv8-a architecture reference manual
+(ARM DDI 0487A.k) Chapter 'Part H: External debug', the CPU can integrate
+debug module and it is mainly used for two modes: self-hosted debug and
+external debug. Usually the external debug mode is well known as the external
+debugger connects with SoC from JTAG port; on the other hand the program can
+explore debugging method which rely on self-hosted debug mode, this document
+is to focus on this part.
+
+The debug module provides sample-based profiling extension, which can be used
+to sample CPU program counter, secure state and exception level, etc; usually
+every CPU has one dedicated debug module to be connected. Based on self-hosted
+debug mechanism, Linux kernel can access these related registers from mmio
+region when the kernel panic happens. The callback notifier for kernel panic
+will dump related registers for every CPU; finally this is good for assistant
+analysis for panic.
+
+
+Implementation
+--------------
+
+- During driver registration, use EDDEVID and EDDEVID1 two device ID
+  registers to decide if sample-based profiling is implemented or not. On some
+  platforms this hardware feature is fully or partialy implemented; and if
+  this feature is not supported then registration will fail.
+
+- When write this doc, the debug driver mainly relies on three sampling
+  registers. The kernel panic callback notifier gathers info from EDPCSR
+  EDVIDSR and EDCIDSR; from EDPCSR we can get program counter, EDVIDSR has
+  information for secure state, exception level, bit width, etc; EDCIDSR is
+  context ID value which contains the sampled value of CONTEXTIDR_EL1.
+
+- The driver supports CPU running mode with either AArch64 or AArch32. The
+  registers naming convention is a bit different between them, AArch64 uses
+  'ED' for register prefix (ARM DDI 0487A.k, chapter H9.1) and AArch32 uses
+  'DBG' as prefix (ARM DDI 0487A.k, chapter G5.1). The driver is unified to
+  use AArch64 naming convention.
+
+- ARMv8-a (ARM DDI 0487A.k) and ARMv7-a (ARM DDI 0406C.b) have different
+  register bits definition. So the driver consolidates two difference:
+
+  If PCSROffset=0b0000. ARMv8-a doesn't apply offset on PCSR, but ARMv7-a
+  defines "PCSR samples are offset by a value that depends on the instruction
+  set state". For ARMv7-a, the driver checks furthermore if CPU runs with ARM
+  or thumb instruction set and calibrate PCSR value, the detailed description
+  for offset is in ARMv7-a ARM (ARM DDI 0406C.b) chapter C11.11.34 "DBGPCSR,
+  Program Counter Sampling Register".
+
+  If PCSROffset=0b0010, ARMv8-a defines "EDPCSR implemented, and samples have
+  no offset applied and do not sample the instruction set state in AArch32
+  state". So for the case when CPU runs with AArch32 state and PCSROffset=
+  0b0010, the driver considers PCSR doesn't really work.
+
+
+Clock and power domain
+----------------------
+
+Before accessing debug registers, we should ensure the clock and power domain
+have been enabled properly. In ARMv8-a ARM (ARM DDI 0487A.k) chapter 'H9.1
+Debug registers', the debug registers are spread into two domains: the debug
+domain and the CPU domain.
+
+                                +---------------+
+                                |               |
+                                |               |
+                     +----------+--+            |
+          dbg_clk -->|          |**|            |<-- cpu_clk
+                     |    Debug |**|   CPU      |
+           dbg_pd -->|          |**|            |<-- cpu_pd
+                     +----------+--+            |
+                                |               |
+                                |               |
+                                +---------------+
+
+For debug domain, the user uses DT binding "clocks" and "power-domains" to
+specify the corresponding clock source and power supply for the debug logic.
+The driver calls the pm_runtime_{put|get} operations as needed to handle the
+debug power domain.
+
+For CPU domain, the different SoC designs have different power management
+schemes and finally this heavily impacts external debug module. So we can
+divide into below cases:
+
+- On systems with a sane power controller which can behave correctly with
+  respect to CPU power domain, the CPU power domain can be controlled by
+  register EDPRCR in driver. The driver firstly writes bit EDPRCR.COREPURQ
+  to power up the CPU, and then writes bit EDPRCR.CORENPDRQ for emulation
+  of CPU power down. As result, this can ensure the CPU power domain is
+  powered on properly during the period when access debug related registers;
+
+- Some designs will power down an entire cluster if all CPUs on the cluster
+  are powered down - including the parts of the debug registers that should
+  remain powered in the debug power domain. The bits in EDPRCR are not
+  respected in these cases, so these designs do not really support debug over
+  power down in the way that the CoreSight / Debug designers anticipated.
+  This means that even checking EDPRSR has the potential to cause a bus hang
+  if the target register is unpowered.
+
+  In this case, accessing to the debug registers while they are not powered
+  is a recipe for disaster; so we need preventing CPU low power states at boot
+  time or when user enable module at the run time. Please see chapter
+  "How to use the module" for detailed usage info for this.
+
+
+Device Tree Bindings
+--------------------
+
+See Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt for details.
+
+
+How to use the module
+---------------------
+
+If you want to enable debugging functionality at boot time, you can add
+"coresight_cpu_debug.enable=1" to the kernel command line parameter.
+
+The driver also can work as module, so can enable the debugging when insmod
+module:
+# insmod coresight_cpu_debug.ko debug=1
+
+When boot time or insmod module you have not enabled the debugging, the driver
+uses the debugfs file system to provide a knob to dynamically enable or disable
+debugging:
+
+To enable it, write a '1' into /sys/kernel/debug/coresight_cpu_debug/enable:
+# echo 1 > /sys/kernel/debug/coresight_cpu_debug/enable
+
+To disable it, write a '0' into /sys/kernel/debug/coresight_cpu_debug/enable:
+# echo 0 > /sys/kernel/debug/coresight_cpu_debug/enable
+
+As explained in chapter "Clock and power domain", if you are working on one
+platform which has idle states to power off debug logic and the power
+controller cannot work well for the request from EDPRCR, then you should
+firstly constraint CPU idle states before enable CPU debugging feature; so can
+ensure the accessing to debug logic.
+
+If you want to limit idle states at boot time, you can use "nohlt" or
+"cpuidle.off=1" in the kernel command line.
+
+At the runtime you can disable idle states with below methods:
+
+Set latency request to /dev/cpu_dma_latency to disable all CPUs specific idle
+states (if latency = 0uS then disable all idle states):
+# echo "what_ever_latency_you_need_in_uS" > /dev/cpu_dma_latency
+
+Disable specific CPU's specific idle state:
+# echo 1 > /sys/devices/system/cpu/cpu$cpu/cpuidle/state$state/disable
+
+
+Output format
+-------------
+
+Here is an example of the debugging output format:
+
+ARM external debug module:
+CPU[0]:
+ EDPRSR:  0000000b (Power:On DLK:Unlock)
+ EDPCSR:  [<ffff00000808eb54>] handle_IPI+0xe4/0x150
+ EDCIDSR: 00000000
+ EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0)
+CPU[1]:
+ EDPRSR:  0000000b (Power:On DLK:Unlock)
+ EDPCSR:  [<ffff0000087a64c0>] debug_notifier_call+0x108/0x288
+ EDCIDSR: 00000000
+ EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0)
-- 
2.7.4

^ permalink raw reply related

* [PATCH v6 1/8] coresight: bindings for CPU debug module
From: Leo Yan @ 2017-04-06 13:30 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd, linux-doc,
	linux-kernel, devicetree, linux-arm-kernel, linux-arm-msm,
	linux-soc, Mike Leach, Sudeep Holla
  Cc: Leo Yan
In-Reply-To: <1491485461-22800-1-git-send-email-leo.yan@linaro.org>

According to ARMv8 architecture reference manual (ARM DDI 0487A.k)
Chapter 'Part H: External debug', the CPU can integrate debug module
and it can support self-hosted debug and external debug. Especially
for supporting self-hosted debug, this means the program can access
the debug module from mmio region; and usually the mmio region is
integrated with coresight.

So add document for binding debug component, includes binding to APB
clock; and also need specify the CPU node which the debug module is
dedicated to specific CPU.

Suggested-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 .../bindings/arm/coresight-cpu-debug.txt           | 49 ++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt

diff --git a/Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt b/Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt
new file mode 100644
index 0000000..2982912
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt
@@ -0,0 +1,49 @@
+* CoreSight CPU Debug Component:
+
+CoreSight CPU debug component are compliant with the ARMv8 architecture
+reference manual (ARM DDI 0487A.k) Chapter 'Part H: External debug'. The
+external debug module is mainly used for two modes: self-hosted debug and
+external debug, and it can be accessed from mmio region from Coresight
+and eventually the debug module connects with CPU for debugging. And the
+debug module provides sample-based profiling extension, which can be used
+to sample CPU program counter, secure state and exception level, etc;
+usually every CPU has one dedicated debug module to be connected.
+
+Required properties:
+
+- compatible : should be "arm,coresight-cpu-debug"; supplemented with
+               "arm,primecell" since this driver is using the AMBA bus
+	       interface.
+
+- reg : physical base address and length of the register set.
+
+- clocks : the clock associated to this component.
+
+- clock-names : the name of the clock referenced by the code. Since we are
+                using the AMBA framework, the name of the clock providing
+		the interconnect should be "apb_pclk" and the clock is
+		mandatory. The interface between the debug logic and the
+		processor core is clocked by the internal CPU clock, so it
+		is enabled with CPU clock by default.
+
+- cpu : the CPU phandle the debug module is affined to. When omitted
+	the module is considered to belong to CPU0.
+
+Optional properties:
+
+- power-domains: a phandle to the debug power domain. We use "power-domains"
+                 binding to turn on the debug logic if it has own dedicated
+		 power domain and if necessary to use "cpuidle.off=1" or
+		 "nohlt" in the kernel command line or sysfs node to
+		 constrain idle states to ensure registers in the CPU power
+		 domain are accessible.
+
+Example:
+
+	debug@f6590000 {
+		compatible = "arm,coresight-cpu-debug","arm,primecell";
+		reg = <0 0xf6590000 0 0x1000>;
+		clocks = <&sys_ctrl HI6220_DAPB_CLK>;
+		clock-names = "apb_pclk";
+		cpu = <&cpu0>;
+	};
-- 
2.7.4

^ permalink raw reply related

* [PATCH v6 0/8] coresight: enable debug module
From: Leo Yan @ 2017-04-06 13:30 UTC (permalink / raw)
  To: Jonathan Corbet, Rob Herring, Mark Rutland, Wei Xu,
	Catalin Marinas, Will Deacon, Andy Gross, David Brown,
	Mathieu Poirier, Suzuki K Poulose, Stephen Boyd,
	linux-doc-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	linux-arm-msm-u79uwXL29TY76Z2rM5mHXA,
	linux-soc-u79uwXL29TY76Z2rM5mHXA, Mike Leach, Sudeep Holla
  Cc: Leo Yan

ARMv8 architecture reference manual (ARM DDI 0487A.k) Chapter H7 "The
Sample-based Profiling Extension" has description for sampling
registers, we can utilize these registers to check program counter
value with combined CPU exception level, secure state, etc. So this is
helpful for CPU lockup bugs, e.g. if one CPU has run into infinite loop
with IRQ disabled; the 'hang' CPU cannot switch context and handle any
interrupt, so it cannot handle SMP call for stack dump, etc.

This patch series is to enable coresight debug module with sample-based
registers and register call back notifier for PCSR register dumping
when panic happens, so we can see below dumping info for panic; and
this patch series has considered the conditions for access permission
for debug registers self, so this can avoid access debug registers when
CPU power domain is off; the driver also try to figure out the CPU is
in secure or non-secure state.

Patch 0001 is to document the dt binding; patch 0002 is to document
boot parameters used in kernel command line and add one detailed
document to describe the Coresight debug module implementation, the
clock and power domain impaction on the driver, some examples for
usage.

Patch 0003 is used to fix the func of_get_coresight_platform_data()
doesn't properly drop the reference to the CPU node pointer; and
patch 0004 is refactor to add new function of_coresight_get_cpu().
Patch 0005 is to add const quality to structure device_node.

Patch 0006 is the driver for CPU debug module.

Patch 0007 in this series are to enable debug unit on 96boards Hikey,
Patch 0008 is to enable debug on 96boards DB410c. Have verified on both
two boards.

We can enable debugging with two methods, adding parameters into kernel
command line for build-in module:
  coresight_cpu_debug.enable=1

Or we can wait the system has booted up to use debugfs nodes to enable
debugging:
  # echo 1 > /sys/kernel/debug/coresight_cpu_debug/enable

As result we can get below log after input command:
echo c > /proc/sysrq-trigger:

ARM external debug module:
CPU[0]:
 EDPRSR:  0000000b (Power:On DLK:Unlock)
 EDPCSR:  [<ffff00000808eb54>] handle_IPI+0xe4/0x150
 EDCIDSR: 00000000
 EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0)
CPU[1]:
 EDPRSR:  0000000b (Power:On DLK:Unlock)
 EDPCSR:  [<ffff0000087a64c0>] debug_notifier_call+0x108/0x288
 EDCIDSR: 00000000
 EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0)

[...]

Changes from v5:
* According to Suzuki and Mathieu suggestions, refined debug module
  driver to drop unused structure members, refactored initialization
  code to distinguish hardware implementation features, refactored
  flow for forcing CPU powered up, supported pm_runtime operations.
* Added one new doc file: Documentation/trace/coresight-cpu-debug.txt,
  which is used to describe detailed info for implementation, clock
  and power domain impaction on debug module, and exmaples for common
  usage.
* Removed "idle constraints" from debug driver.

Changes from v4:
* This version is mainly credit to ARM colleagues many contribution
  ideas for better quality (Thanks a lot Suzuki, Mike and Sudeep!).
* According to Suzuki suggestion, refined debug module driver to avoid
  memory leak for drvdata struct, handle PCSAMPLE_MODE=1, use flag
  drvdata.pc_has_offset to indicate if PCSR has offset, minor fixes.
* According to Mathieu suggestion, refined dt binding description.
* Changed driver to support module mode;
* According to Mike suggestion and very appreciate the pseudo code,
  added support to force CPU powered up with register EDPRCR;
* According to discussions, added command line and debugfs nodes to
  support enabling debugging for boot time, or later can dynamically
  enable/disable debugging by debugfs.
* According to Rob Herring suggestion, one minor fixes in DT binding.
* According to Stephen Boyd suggestion, add const quality to structure
  device_node. And used use of_cpu_device_node_get() to replace
  of_get_cpu_node() in patch 0003.

Changes from v3:
* Added Suzuki K Poulose's patch to fix issue for the func
  of_get_coresight_platform_data() doesn't properly drop the reference
  to the CPU node pointer.
* According to Suzuki suggestion, added code to handl the corner case
  for ARMv8 CPU with aarch32 mode.
* According to Suzuki suggestion, changed compatible string to
  "arm,coresight-cpu-debug".
* According to Mathieu suggestion, added "power-domains" as optional
  properties.

Changes from v2:
* According to Mathieu Poirier suggestion, applied some minor fixes.
* Added two extra patches for enabling debug module on Hikey.

Changes from v1:
* According to Mike Leach suggestion, removed the binding for debug
  module clocks which have been directly provided by CPU clocks.
* According to Mathieu Poirier suggestion, added function
  of_coresight_get_cpu() and some minor refactors for debug module
  driver.

Changes from RFC:
* According to Mike Leach suggestion, added check for EDPRSR to avoid
  lockup; added supporting EDVIDSR and EDCIDSR registers.
* According to Mark Rutland and Mathieu Poirier suggestion, rewrote
  the documentation for DT binding.
* According to Mark and Mathieu suggestion, refined debug driver.


Leo Yan (7):
  coresight: bindings for CPU debug module
  doc: Add documentation for Coresight CPU debug
  coresight: refactor with function of_coresight_get_cpu
  coresight: use const for device_node structures
  coresight: add support for CPU debug module
  arm64: dts: hi6220: register debug module
  arm64: dts: qcom: msm8916: Add debug unit

Suzuki K Poulose (1):
  coresight: of_get_coresight_platform_data: Add missing of_node_put

 Documentation/admin-guide/kernel-parameters.txt    |   7 +
 .../bindings/arm/coresight-cpu-debug.txt           |  49 ++
 Documentation/trace/coresight-cpu-debug.txt        | 173 ++++++
 arch/arm64/boot/dts/hisilicon/hi6220.dtsi          |  64 ++
 arch/arm64/boot/dts/qcom/msm8916.dtsi              |  32 +
 drivers/hwtracing/coresight/Kconfig                |  14 +
 drivers/hwtracing/coresight/Makefile               |   1 +
 drivers/hwtracing/coresight/coresight-cpu-debug.c  | 667 +++++++++++++++++++++
 drivers/hwtracing/coresight/of_coresight.c         |  44 +-
 include/linux/coresight.h                          |   6 +-
 10 files changed, 1041 insertions(+), 16 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt
 create mode 100644 Documentation/trace/coresight-cpu-debug.txt
 create mode 100644 drivers/hwtracing/coresight/coresight-cpu-debug.c

-- 
2.7.4

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^ permalink raw reply

* Re: [PATCH 3/4] pwm: tegra: Add DT binding details to configure pin in suspends/resume
From: Laxman Dewangan @ 2017-04-06 13:19 UTC (permalink / raw)
  To: Thierry Reding, Jon Hunter
  Cc: robh+dt, mark.rutland, linux-pwm, devicetree, linux-tegra,
	linux-kernel, Linus Walleij
In-Reply-To: <20170406130315.GB7784@ulmo.ba.sec>


On Thursday 06 April 2017 06:33 PM, Thierry Reding wrote:
> * PGP Signed by an unknown key
>
> On Thu, Apr 06, 2017 at 09:57:09AM +0100, Jon Hunter wrote:
>> On 05/04/17 15:13, Laxman Dewangan wrote:
>>> +state of the system. The configuration of pin is provided via the pinctrl
>>> +DT node as detailed in the pinctrl DT binding document
>>> +	Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
>>> +
>>> +The PWM node will have following optional properties.
>>> +pinctrl-names:	Pin state names. Must be "suspend" and "resume".
>> Why not just use the pre-defined names here? There is a pre-defined name
>> for "default", "idle" and "sleep" and then you can use the following
>> APIs and avoid the lookup of the state ...
>>
>> pinctrl_pm_select_default_state()
>> pinctrl_pm_select_idle_state()
>> pinctrl_pm_select_sleep_state()
>>
>> Note for i2c [0][1], I used "default" as the active/on state (which I
>> know is not that descriptive) and then used 'idle' as the suspended
>> state. This way we don't need any custom names.
> Agreed, I think that's how these states are meant to be used.
I did quick grep for the pinctrl_pm_select_* functions in the code tree 
and found usage of these APIs in some of the places.
I am taking the reference of i2c-st, i2c-nomadic and 
extcon/extcon-usb-gpio.c drivers and from this the interpretation is

default state: When interface active and transfer need to be done in IO 
interface.
idle state: Active state of the system but interface is not active, put 
in non-active state of the interface.
sleep state: When system entering into suspend and IO interface is going 
to be inactive.

So in PWM case, we will need the "default" and "sleep" state.

In suspend(), set the "sleep" state and in resume, set the "default" state.

+ Linus W as I refereed his st/nomadik driver for reference.

^ permalink raw reply


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