[PATCH v3] media: st-rc: Add ST remote control driver

[PATCH v3] media: st-rc: Add ST remote control driver

[Srinivas KANDAGATLA]

From: Srinivas Kandagatla <srinivas.kandagatla@st.com>

This patch adds support to ST RC driver, which is basically a IR/UHF
receiver and transmitter. This IP (IRB) is common across all the ST
parts for settop box platforms. IRB is embedded in ST COMMS IP block.
It supports both Rx & Tx functionality.

In this driver adds only Rx functionality via LIRC codec.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Acked-by: Sean Young <sean@mess.org>
---
Hi Chehab,

This is a very simple rc driver for IRB controller found in STi ARM CA9 SOCs.
STi ARM SOC support went in 3.11 recently.
This driver is a raw driver which feeds data to lirc codec for the user lircd
to decode the keys.

This patch is based on git://linuxtv.org/media_tree.git master branch.

If its not too late can you please consider this driver for 3.12.

Changes since v2:
	- Updated Kconfig dependencies as suggested by Sean and Chehab.
	- Fixed a logical check spoted by Sean.

Changes since v1:
	- Device tree bindings cleaned up as suggested by Mark and Pawel
	- use ir_raw_event_reset under overflow conditions as suggested by Sean.
	- call ir_raw_event_handle in interrupt handler as suggested by Sean.
	- correct allowed_protos flag with RC_BIT_ types as suggested by Sean.
	- timeout and rx resolution added as suggested by Sean.

Thankyou all for reviewing and commenting.

Thanks,
srini

 Documentation/devicetree/bindings/media/st-rc.txt |   24 ++
 drivers/media/rc/Kconfig                          |   10 +
 drivers/media/rc/Makefile                         |    1 +
 drivers/media/rc/st_rc.c                          |  396 +++++++++++++++++++++
 4 files changed, 431 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/media/st-rc.txt
 create mode 100644 drivers/media/rc/st_rc.c

diff --git a/Documentation/devicetree/bindings/media/st-rc.txt b/Documentation/devicetree/bindings/media/st-rc.txt
new file mode 100644
index 0000000..20fe264
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/st-rc.txt
@@ -0,0 +1,24 @@
+Device-Tree bindings for ST IRB IP
+
+Required properties:
+	- compatible: should be "st,comms-irb".
+	- reg: base physical address of the controller and length of memory
+	mapped  region.
+	- interrupts: interrupt number to the cpu. The interrupt specifier
+	format depends on the interrupt controller parent.
+
+Optional properties:
+	- rx-mode: can be "infrared" or "uhf".
+	- tx-mode: should be "infrared".
+	- pinctrl-names, pinctrl-0: the pincontrol settings to configure
+	muxing properly for IRB pins.
+	- clocks : phandle of clock.
+
+Example node:
+
+	rc: rc@fe518000 {
+		compatible	= "st,comms-irb";
+		reg		= <0xfe518000 0x234>;
+		interrupts	=  <0 203 0>;
+		rx-mode		= "infrared";
+	};
diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index 11e84bc..557afc5 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -322,4 +322,14 @@ config IR_GPIO_CIR
 	   To compile this driver as a module, choose M here: the module will
 	   be called gpio-ir-recv.
 
+config RC_ST
+	tristate "ST remote control receiver"
+	depends on ARCH_STI && RC_CORE
+	help
+	 Say Y here if you want support for ST remote control driver
+	 which allows both IR and UHF RX.
+	 The driver passes raw pluse and space information to the LIRC decoder.
+
+	 If you're not sure, select N here.
+
 endif #RC_DEVICES
diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
index 56bacf0..f4eb32c 100644
--- a/drivers/media/rc/Makefile
+++ b/drivers/media/rc/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_RC_LOOPBACK) += rc-loopback.o
 obj-$(CONFIG_IR_GPIO_CIR) += gpio-ir-recv.o
 obj-$(CONFIG_IR_IGUANA) += iguanair.o
 obj-$(CONFIG_IR_TTUSBIR) += ttusbir.o
+obj-$(CONFIG_RC_ST) += st_rc.o
diff --git a/drivers/media/rc/st_rc.c b/drivers/media/rc/st_rc.c
new file mode 100644
index 0000000..e2dad9c
--- /dev/null
+++ b/drivers/media/rc/st_rc.c
@@ -0,0 +1,396 @@
+/*
+ * Copyright (C) 2013 STMicroelectronics Limited
+ * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <media/rc-core.h>
+#include <linux/pinctrl/consumer.h>
+
+struct st_rc_device {
+	struct device			*dev;
+	int				irq;
+	int				irq_wake;
+	struct clk			*sys_clock;
+	void				*base;	/* Register base address */
+	void				*rx_base;/* RX Register base address */
+	struct rc_dev			*rdev;
+	bool				overclocking;
+	int				sample_mult;
+	int				sample_div;
+	bool				rxuhfmode;
+};
+
+/* Registers */
+#define IRB_SAMPLE_RATE_COMM	0x64	/* sample freq divisor*/
+#define IRB_CLOCK_SEL		0x70	/* clock select       */
+#define IRB_CLOCK_SEL_STATUS	0x74	/* clock status       */
+/* IRB IR/UHF receiver registers */
+#define IRB_RX_ON               0x40	/* pulse time capture */
+#define IRB_RX_SYS              0X44	/* sym period capture */
+#define IRB_RX_INT_EN           0x48	/* IRQ enable (R/W)   */
+#define IRB_RX_INT_STATUS       0x4C	/* IRQ status (R/W)   */
+#define IRB_RX_EN               0x50	/* Receive enablei    */
+#define IRB_MAX_SYM_PERIOD      0x54	/* max sym value      */
+#define IRB_RX_INT_CLEAR        0x58	/* overrun status     */
+#define IRB_RX_STATUS           0x6C	/* receive status     */
+#define IRB_RX_NOISE_SUPPR      0x5C	/* noise suppression  */
+#define IRB_RX_POLARITY_INV     0x68	/* polarity inverter  */
+
+/**
+ * IRQ set: Enable full FIFO                 1  -> bit  3;
+ *          Enable overrun IRQ               1  -> bit  2;
+ *          Enable last symbol IRQ           1  -> bit  1:
+ *          Enable RX interrupt              1  -> bit  0;
+ */
+#define IRB_RX_INTS		0x0f
+#define IRB_RX_OVERRUN_INT	0x04
+ /* maximum symbol period (microsecs),timeout to detect end of symbol train */
+#define MAX_SYMB_TIME		0x5000
+#define IRB_SAMPLE_FREQ		10000000
+#define	IRB_FIFO_NOT_EMPTY	0xff00
+#define IRB_OVERFLOW		0x4
+#define IRB_TIMEOUT		0xffff
+#define IR_ST_NAME "st-rc"
+
+static void st_rc_send_lirc_timeout(struct rc_dev *rdev)
+{
+	DEFINE_IR_RAW_EVENT(ev);
+	ev.timeout = true;
+	ir_raw_event_store(rdev, &ev);
+}
+
+/**
+ * RX graphical example to better understand the difference between ST IR block
+ * output and standard definition used by LIRC (and most of the world!)
+ *
+ *           mark                                     mark
+ *      |-IRB_RX_ON-|                            |-IRB_RX_ON-|
+ *      ___  ___  ___                            ___  ___  ___             _
+ *      | |  | |  | |                            | |  | |  | |             |
+ *      | |  | |  | |         space 0            | |  | |  | |   space 1   |
+ * _____| |__| |__| |____________________________| |__| |__| |_____________|
+ *
+ *      |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|
+ *
+ *      |------------- encoding bit 0 -----------|---- encoding bit 1 -----|
+ *
+ * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so
+ * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)
+ * The mark time represents the amount of time the carrier (usually 36-40kHz)
+ * is detected.The above examples shows Pulse Width Modulation encoding where
+ * bit 0 is represented by space>mark.
+ */
+
+static irqreturn_t st_rc_rx_interrupt(int irq, void *data)
+{
+	unsigned int symbol, mark = 0;
+	struct st_rc_device *dev = data;
+	int last_symbol = 0;
+	u32 status;
+	DEFINE_IR_RAW_EVENT(ev);
+
+	if (dev->irq_wake)
+		pm_wakeup_event(dev->dev, 0);
+
+	status  = readl(dev->rx_base + IRB_RX_STATUS);
+
+	while (status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)) {
+		u32 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);
+		if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {
+			/* discard the entire collection in case of errors!  */
+			ir_raw_event_reset(dev->rdev);
+			dev_info(dev->dev, "IR RX overrun\n");
+			writel(IRB_RX_OVERRUN_INT,
+					dev->rx_base + IRB_RX_INT_CLEAR);
+			continue;
+		}
+
+		symbol = readl(dev->rx_base + IRB_RX_SYS);
+		mark = readl(dev->rx_base + IRB_RX_ON);
+
+		if (symbol == IRB_TIMEOUT)
+			last_symbol = 1;
+
+		 /* Ignore any noise */
+		if ((mark > 2) && (symbol > 1)) {
+			symbol -= mark;
+			if (dev->overclocking) { /* adjustments to timings */
+				symbol *= dev->sample_mult;
+				symbol /= dev->sample_div;
+				mark *= dev->sample_mult;
+				mark /= dev->sample_div;
+			}
+
+			ev.duration = US_TO_NS(mark);
+			ev.pulse = true;
+			ir_raw_event_store(dev->rdev, &ev);
+
+			if (!last_symbol) {
+				ev.duration = US_TO_NS(symbol);
+				ev.pulse = false;
+				ir_raw_event_store(dev->rdev, &ev);
+			} else  {
+				st_rc_send_lirc_timeout(dev->rdev);
+			}
+
+		}
+		last_symbol = 0;
+		status  = readl(dev->rx_base + IRB_RX_STATUS);
+	}
+
+	writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR);
+
+	/* Empty software fifo */
+	ir_raw_event_handle(dev->rdev);
+	return IRQ_HANDLED;
+}
+
+static void st_rc_hardware_init(struct st_rc_device *dev)
+{
+	int baseclock, freqdiff;
+	unsigned int rx_max_symbol_per = MAX_SYMB_TIME;
+	unsigned int rx_sampling_freq_div;
+
+	clk_prepare_enable(dev->sys_clock);
+	baseclock = clk_get_rate(dev->sys_clock);
+
+	/* IRB input pins are inverted internally from high to low. */
+	writel(1, dev->rx_base + IRB_RX_POLARITY_INV);
+
+	rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ;
+	writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM);
+
+	freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ);
+	if (freqdiff) { /* over clocking, workout the adjustment factors */
+		dev->overclocking = true;
+		dev->sample_mult = 1000;
+		dev->sample_div = baseclock / (10000 * rx_sampling_freq_div);
+		rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div;
+	}
+
+	writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD);
+}
+
+static int st_rc_remove(struct platform_device *pdev)
+{
+	struct st_rc_device *rc_dev = platform_get_drvdata(pdev);
+	clk_disable_unprepare(rc_dev->sys_clock);
+	rc_unregister_device(rc_dev->rdev);
+	return 0;
+}
+
+static int st_rc_open(struct rc_dev *rdev)
+{
+	struct st_rc_device *dev = rdev->priv;
+	unsigned long flags;
+	local_irq_save(flags);
+	/* enable interrupts and receiver */
+	writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN);
+	writel(0x01, dev->rx_base + IRB_RX_EN);
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static void st_rc_close(struct rc_dev *rdev)
+{
+	struct st_rc_device *dev = rdev->priv;
+	/* disable interrupts and receiver */
+	writel(0x00, dev->rx_base + IRB_RX_EN);
+	writel(0x00, dev->rx_base + IRB_RX_INT_EN);
+}
+
+static int st_rc_probe(struct platform_device *pdev)
+{
+	int ret = -EINVAL;
+	struct rc_dev *rdev;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct st_rc_device *rc_dev;
+	struct device_node *np = pdev->dev.of_node;
+	const char *rx_mode;
+
+	rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL);
+
+	if (!rc_dev)
+		return -ENOMEM;
+
+	rdev = rc_allocate_device();
+
+	if (!rdev)
+		return -ENOMEM;
+
+	if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) {
+
+		if (!strcmp(rx_mode, "uhf")) {
+			rc_dev->rxuhfmode = true;
+		} else if (!strcmp(rx_mode, "infrared")) {
+			rc_dev->rxuhfmode = false;
+		} else {
+			dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode);
+			goto err;
+		}
+
+	} else {
+		goto err;
+	}
+
+	rc_dev->sys_clock = devm_clk_get(dev, NULL);
+	if (IS_ERR(rc_dev->sys_clock)) {
+		dev_err(dev, "System clock not found\n");
+		ret = PTR_ERR(rc_dev->sys_clock);
+		goto err;
+	}
+
+	rc_dev->irq = platform_get_irq(pdev, 0);
+	if (rc_dev->irq < 0) {
+		ret = rc_dev->irq;
+		goto clkerr;
+	}
+
+	ret = -ENODEV;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		goto clkerr;
+
+	rc_dev->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(rc_dev->base))
+		goto clkerr;
+
+	if (rc_dev->rxuhfmode)
+		rc_dev->rx_base = rc_dev->base + 0x40;
+	else
+		rc_dev->rx_base = rc_dev->base;
+
+	rc_dev->dev = dev;
+	platform_set_drvdata(pdev, rc_dev);
+	st_rc_hardware_init(rc_dev);
+
+	rdev->driver_type = RC_DRIVER_IR_RAW;
+	rdev->allowed_protos = RC_BIT_ALL;
+	/* rx sampling rate is 10Mhz */
+	rdev->rx_resolution = 100;
+	rdev->timeout = US_TO_NS(MAX_SYMB_TIME);
+	rdev->priv = rc_dev;
+	rdev->open = st_rc_open;
+	rdev->close = st_rc_close;
+	rdev->driver_name = IR_ST_NAME;
+	rdev->map_name = RC_MAP_LIRC;
+	rdev->input_name = "ST Remote Control Receiver";
+
+	/* enable wake via this device */
+	device_set_wakeup_capable(dev, true);
+	device_set_wakeup_enable(dev, true);
+
+	ret = rc_register_device(rdev);
+	if (ret < 0)
+		goto clkerr;
+
+	rc_dev->rdev = rdev;
+	if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt,
+			IRQF_NO_SUSPEND, IR_ST_NAME, rc_dev) < 0) {
+		dev_err(dev, "IRQ %d register failed\n", rc_dev->irq);
+		ret = -EINVAL;
+		goto rcerr;
+	}
+
+	/**
+	 * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW
+	 * lircd expects a long space first before a signal train to sync.
+	 */
+	st_rc_send_lirc_timeout(rdev);
+
+	dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR");
+
+	return ret;
+rcerr:
+	rc_unregister_device(rdev);
+	rdev = NULL;
+clkerr:
+	clk_disable_unprepare(rc_dev->sys_clock);
+err:
+	rc_free_device(rdev);
+	dev_err(dev, "Unable to register device (%d)\n", ret);
+	return ret;
+}
+
+#ifdef CONFIG_PM
+static int st_rc_suspend(struct device *dev)
+{
+	struct st_rc_device *rc_dev = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev)) {
+		if (!enable_irq_wake(rc_dev->irq))
+			rc_dev->irq_wake = 1;
+		else
+			return -EINVAL;
+	} else {
+		pinctrl_pm_select_sleep_state(dev);
+		writel(0x00, rc_dev->rx_base + IRB_RX_EN);
+		writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
+		clk_disable_unprepare(rc_dev->sys_clock);
+	}
+
+	return 0;
+}
+
+static int st_rc_resume(struct device *dev)
+{
+	struct st_rc_device *rc_dev = dev_get_drvdata(dev);
+	struct rc_dev	*rdev = rc_dev->rdev;
+
+	if (rc_dev->irq_wake) {
+		disable_irq_wake(rc_dev->irq);
+		rc_dev->irq_wake = 0;
+	} else {
+		pinctrl_pm_select_default_state(dev);
+		st_rc_hardware_init(rc_dev);
+		if (rdev->users) {
+			writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN);
+			writel(0x01, rc_dev->rx_base + IRB_RX_EN);
+		}
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume);
+#endif
+
+#ifdef CONFIG_OF
+static struct of_device_id st_rc_match[] = {
+	{ .compatible = "st,comms-irb", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, st_rc_match);
+#endif
+
+static struct platform_driver st_rc_driver = {
+	.driver = {
+		.name = IR_ST_NAME,
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(st_rc_match),
+#ifdef CONFIG_PM
+		.pm     = &st_rc_pm_ops,
+#endif
+	},
+	.probe = st_rc_probe,
+	.remove = st_rc_remove,
+};
+
+module_platform_driver(st_rc_driver);
+
+MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");
+MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");
+MODULE_LICENSE("GPL");
-- 
1.7.6.5

Re: [PATCH v3] media: st-rc: Add ST remote control driver

[Mark Rutland]

On Thu, Aug 29, 2013 at 01:06:52PM +0100, Srinivas KANDAGATLA wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla-qxv4g6HH51o@public.gmane.org>
> 
> This patch adds support to ST RC driver, which is basically a IR/UHF
> receiver and transmitter. This IP (IRB) is common across all the ST
> parts for settop box platforms. IRB is embedded in ST COMMS IP block.
> It supports both Rx & Tx functionality.
> 
> In this driver adds only Rx functionality via LIRC codec.
> 
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla-qxv4g6HH51o@public.gmane.org>
> Acked-by: Sean Young <sean-hENCXIMQXOg@public.gmane.org>
> ---
> Hi Chehab,
> 
> This is a very simple rc driver for IRB controller found in STi ARM CA9 SOCs.
> STi ARM SOC support went in 3.11 recently.
> This driver is a raw driver which feeds data to lirc codec for the user lircd
> to decode the keys.
> 
> This patch is based on git://linuxtv.org/media_tree.git master branch.
> 
> If its not too late can you please consider this driver for 3.12.
> 
> Changes since v2:
>         - Updated Kconfig dependencies as suggested by Sean and Chehab.
>         - Fixed a logical check spoted by Sean.
> 
> Changes since v1:
>         - Device tree bindings cleaned up as suggested by Mark and Pawel
>         - use ir_raw_event_reset under overflow conditions as suggested by Sean.
>         - call ir_raw_event_handle in interrupt handler as suggested by Sean.
>         - correct allowed_protos flag with RC_BIT_ types as suggested by Sean.
>         - timeout and rx resolution added as suggested by Sean.
> 
> Thankyou all for reviewing and commenting.
> 
> Thanks,
> srini
> 
>  Documentation/devicetree/bindings/media/st-rc.txt |   24 ++
>  drivers/media/rc/Kconfig                          |   10 +
>  drivers/media/rc/Makefile                         |    1 +
>  drivers/media/rc/st_rc.c                          |  396 +++++++++++++++++++++
>  4 files changed, 431 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/media/st-rc.txt
>  create mode 100644 drivers/media/rc/st_rc.c
> 
> diff --git a/Documentation/devicetree/bindings/media/st-rc.txt b/Documentation/devicetree/bindings/media/st-rc.txt
> new file mode 100644
> index 0000000..20fe264
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/st-rc.txt
> @@ -0,0 +1,24 @@
> +Device-Tree bindings for ST IRB IP
> +
> +Required properties:
> +       - compatible: should be "st,comms-irb".

This should probably say "should contain" rather than "should be". There
may be future vairants of this device, which will also have a more
specific compatible string.

> +       - reg: base physical address of the controller and length of memory
> +       mapped  region.
> +       - interrupts: interrupt number to the cpu. The interrupt specifier
> +       format depends on the interrupt controller parent.

I don't like the phrase "interrupt number to the cpu". We already have
the term interrupt-specifier to precisely define this. How about:

- interrupts: interrupt-specifier for the sole interrupt generated by
              the device.

> +
> +Optional properties:
> +       - rx-mode: can be "infrared" or "uhf".
> +       - tx-mode: should be "infrared".

Are these required to use rx/tx?

If you don't have a tx-mode or rx-mode, I assume you can't do
anything...

> +       - pinctrl-names, pinctrl-0: the pincontrol settings to configure
> +       muxing properly for IRB pins.

If we're expecting names, the names we expect should be defined.

> +       - clocks : phandle of clock.

This is not just a phandle. This is a phandle + clock-specifier pair.

Cheers,
Mark.

> +
> +Example node:
> +
> +       rc: rc@fe518000 {
> +               compatible      = "st,comms-irb";
> +               reg             = <0xfe518000 0x234>;
> +               interrupts      =  <0 203 0>;
> +               rx-mode         = "infrared";
> +       };
> diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
> index 11e84bc..557afc5 100644
> --- a/drivers/media/rc/Kconfig
> +++ b/drivers/media/rc/Kconfig
> @@ -322,4 +322,14 @@ config IR_GPIO_CIR
>            To compile this driver as a module, choose M here: the module will
>            be called gpio-ir-recv.
> 
> +config RC_ST
> +       tristate "ST remote control receiver"
> +       depends on ARCH_STI && RC_CORE
> +       help
> +        Say Y here if you want support for ST remote control driver
> +        which allows both IR and UHF RX.
> +        The driver passes raw pluse and space information to the LIRC decoder.
> +
> +        If you're not sure, select N here.
> +
>  endif #RC_DEVICES
> diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
> index 56bacf0..f4eb32c 100644
> --- a/drivers/media/rc/Makefile
> +++ b/drivers/media/rc/Makefile
> @@ -30,3 +30,4 @@ obj-$(CONFIG_RC_LOOPBACK) += rc-loopback.o
>  obj-$(CONFIG_IR_GPIO_CIR) += gpio-ir-recv.o
>  obj-$(CONFIG_IR_IGUANA) += iguanair.o
>  obj-$(CONFIG_IR_TTUSBIR) += ttusbir.o
> +obj-$(CONFIG_RC_ST) += st_rc.o
> diff --git a/drivers/media/rc/st_rc.c b/drivers/media/rc/st_rc.c
> new file mode 100644
> index 0000000..e2dad9c
> --- /dev/null
> +++ b/drivers/media/rc/st_rc.c
> @@ -0,0 +1,396 @@
> +/*
> + * Copyright (C) 2013 STMicroelectronics Limited
> + * Author: Srinivas Kandagatla <srinivas.kandagatla-qxv4g6HH51o@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 as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +#include <linux/kernel.h>
> +#include <linux/clk.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <media/rc-core.h>
> +#include <linux/pinctrl/consumer.h>
> +
> +struct st_rc_device {
> +       struct device                   *dev;
> +       int                             irq;
> +       int                             irq_wake;
> +       struct clk                      *sys_clock;
> +       void                            *base;  /* Register base address */
> +       void                            *rx_base;/* RX Register base address */
> +       struct rc_dev                   *rdev;
> +       bool                            overclocking;
> +       int                             sample_mult;
> +       int                             sample_div;
> +       bool                            rxuhfmode;
> +};
> +
> +/* Registers */
> +#define IRB_SAMPLE_RATE_COMM   0x64    /* sample freq divisor*/
> +#define IRB_CLOCK_SEL          0x70    /* clock select       */
> +#define IRB_CLOCK_SEL_STATUS   0x74    /* clock status       */
> +/* IRB IR/UHF receiver registers */
> +#define IRB_RX_ON               0x40   /* pulse time capture */
> +#define IRB_RX_SYS              0X44   /* sym period capture */
> +#define IRB_RX_INT_EN           0x48   /* IRQ enable (R/W)   */
> +#define IRB_RX_INT_STATUS       0x4C   /* IRQ status (R/W)   */
> +#define IRB_RX_EN               0x50   /* Receive enablei    */
> +#define IRB_MAX_SYM_PERIOD      0x54   /* max sym value      */
> +#define IRB_RX_INT_CLEAR        0x58   /* overrun status     */
> +#define IRB_RX_STATUS           0x6C   /* receive status     */
> +#define IRB_RX_NOISE_SUPPR      0x5C   /* noise suppression  */
> +#define IRB_RX_POLARITY_INV     0x68   /* polarity inverter  */
> +
> +/**
> + * IRQ set: Enable full FIFO                 1  -> bit  3;
> + *          Enable overrun IRQ               1  -> bit  2;
> + *          Enable last symbol IRQ           1  -> bit  1:
> + *          Enable RX interrupt              1  -> bit  0;
> + */
> +#define IRB_RX_INTS            0x0f
> +#define IRB_RX_OVERRUN_INT     0x04
> + /* maximum symbol period (microsecs),timeout to detect end of symbol train */
> +#define MAX_SYMB_TIME          0x5000
> +#define IRB_SAMPLE_FREQ                10000000
> +#define        IRB_FIFO_NOT_EMPTY      0xff00
> +#define IRB_OVERFLOW           0x4
> +#define IRB_TIMEOUT            0xffff
> +#define IR_ST_NAME "st-rc"
> +
> +static void st_rc_send_lirc_timeout(struct rc_dev *rdev)
> +{
> +       DEFINE_IR_RAW_EVENT(ev);
> +       ev.timeout = true;
> +       ir_raw_event_store(rdev, &ev);
> +}
> +
> +/**
> + * RX graphical example to better understand the difference between ST IR block
> + * output and standard definition used by LIRC (and most of the world!)
> + *
> + *           mark                                     mark
> + *      |-IRB_RX_ON-|                            |-IRB_RX_ON-|
> + *      ___  ___  ___                            ___  ___  ___             _
> + *      | |  | |  | |                            | |  | |  | |             |
> + *      | |  | |  | |         space 0            | |  | |  | |   space 1   |
> + * _____| |__| |__| |____________________________| |__| |__| |_____________|
> + *
> + *      |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|
> + *
> + *      |------------- encoding bit 0 -----------|---- encoding bit 1 -----|
> + *
> + * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so
> + * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)
> + * The mark time represents the amount of time the carrier (usually 36-40kHz)
> + * is detected.The above examples shows Pulse Width Modulation encoding where
> + * bit 0 is represented by space>mark.
> + */
> +
> +static irqreturn_t st_rc_rx_interrupt(int irq, void *data)
> +{
> +       unsigned int symbol, mark = 0;
> +       struct st_rc_device *dev = data;
> +       int last_symbol = 0;
> +       u32 status;
> +       DEFINE_IR_RAW_EVENT(ev);
> +
> +       if (dev->irq_wake)
> +               pm_wakeup_event(dev->dev, 0);
> +
> +       status  = readl(dev->rx_base + IRB_RX_STATUS);
> +
> +       while (status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)) {
> +               u32 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);
> +               if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {
> +                       /* discard the entire collection in case of errors!  */
> +                       ir_raw_event_reset(dev->rdev);
> +                       dev_info(dev->dev, "IR RX overrun\n");
> +                       writel(IRB_RX_OVERRUN_INT,
> +                                       dev->rx_base + IRB_RX_INT_CLEAR);
> +                       continue;
> +               }
> +
> +               symbol = readl(dev->rx_base + IRB_RX_SYS);
> +               mark = readl(dev->rx_base + IRB_RX_ON);
> +
> +               if (symbol == IRB_TIMEOUT)
> +                       last_symbol = 1;
> +
> +                /* Ignore any noise */
> +               if ((mark > 2) && (symbol > 1)) {
> +                       symbol -= mark;
> +                       if (dev->overclocking) { /* adjustments to timings */
> +                               symbol *= dev->sample_mult;
> +                               symbol /= dev->sample_div;
> +                               mark *= dev->sample_mult;
> +                               mark /= dev->sample_div;
> +                       }
> +
> +                       ev.duration = US_TO_NS(mark);
> +                       ev.pulse = true;
> +                       ir_raw_event_store(dev->rdev, &ev);
> +
> +                       if (!last_symbol) {
> +                               ev.duration = US_TO_NS(symbol);
> +                               ev.pulse = false;
> +                               ir_raw_event_store(dev->rdev, &ev);
> +                       } else  {
> +                               st_rc_send_lirc_timeout(dev->rdev);
> +                       }
> +
> +               }
> +               last_symbol = 0;
> +               status  = readl(dev->rx_base + IRB_RX_STATUS);
> +       }
> +
> +       writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR);
> +
> +       /* Empty software fifo */
> +       ir_raw_event_handle(dev->rdev);
> +       return IRQ_HANDLED;
> +}
> +
> +static void st_rc_hardware_init(struct st_rc_device *dev)
> +{
> +       int baseclock, freqdiff;
> +       unsigned int rx_max_symbol_per = MAX_SYMB_TIME;
> +       unsigned int rx_sampling_freq_div;
> +
> +       clk_prepare_enable(dev->sys_clock);
> +       baseclock = clk_get_rate(dev->sys_clock);
> +
> +       /* IRB input pins are inverted internally from high to low. */
> +       writel(1, dev->rx_base + IRB_RX_POLARITY_INV);
> +
> +       rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ;
> +       writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM);
> +
> +       freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ);
> +       if (freqdiff) { /* over clocking, workout the adjustment factors */
> +               dev->overclocking = true;
> +               dev->sample_mult = 1000;
> +               dev->sample_div = baseclock / (10000 * rx_sampling_freq_div);
> +               rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div;
> +       }
> +
> +       writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD);
> +}
> +
> +static int st_rc_remove(struct platform_device *pdev)
> +{
> +       struct st_rc_device *rc_dev = platform_get_drvdata(pdev);
> +       clk_disable_unprepare(rc_dev->sys_clock);
> +       rc_unregister_device(rc_dev->rdev);
> +       return 0;
> +}
> +
> +static int st_rc_open(struct rc_dev *rdev)
> +{
> +       struct st_rc_device *dev = rdev->priv;
> +       unsigned long flags;
> +       local_irq_save(flags);
> +       /* enable interrupts and receiver */
> +       writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN);
> +       writel(0x01, dev->rx_base + IRB_RX_EN);
> +       local_irq_restore(flags);
> +
> +       return 0;
> +}
> +
> +static void st_rc_close(struct rc_dev *rdev)
> +{
> +       struct st_rc_device *dev = rdev->priv;
> +       /* disable interrupts and receiver */
> +       writel(0x00, dev->rx_base + IRB_RX_EN);
> +       writel(0x00, dev->rx_base + IRB_RX_INT_EN);
> +}
> +
> +static int st_rc_probe(struct platform_device *pdev)
> +{
> +       int ret = -EINVAL;
> +       struct rc_dev *rdev;
> +       struct device *dev = &pdev->dev;
> +       struct resource *res;
> +       struct st_rc_device *rc_dev;
> +       struct device_node *np = pdev->dev.of_node;
> +       const char *rx_mode;
> +
> +       rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL);
> +
> +       if (!rc_dev)
> +               return -ENOMEM;
> +
> +       rdev = rc_allocate_device();
> +
> +       if (!rdev)
> +               return -ENOMEM;
> +
> +       if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) {
> +
> +               if (!strcmp(rx_mode, "uhf")) {
> +                       rc_dev->rxuhfmode = true;
> +               } else if (!strcmp(rx_mode, "infrared")) {
> +                       rc_dev->rxuhfmode = false;
> +               } else {
> +                       dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode);
> +                       goto err;
> +               }
> +
> +       } else {
> +               goto err;
> +       }
> +
> +       rc_dev->sys_clock = devm_clk_get(dev, NULL);
> +       if (IS_ERR(rc_dev->sys_clock)) {
> +               dev_err(dev, "System clock not found\n");
> +               ret = PTR_ERR(rc_dev->sys_clock);
> +               goto err;
> +       }
> +
> +       rc_dev->irq = platform_get_irq(pdev, 0);
> +       if (rc_dev->irq < 0) {
> +               ret = rc_dev->irq;
> +               goto clkerr;
> +       }
> +
> +       ret = -ENODEV;
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (!res)
> +               goto clkerr;
> +
> +       rc_dev->base = devm_ioremap_resource(dev, res);
> +       if (IS_ERR(rc_dev->base))
> +               goto clkerr;
> +
> +       if (rc_dev->rxuhfmode)
> +               rc_dev->rx_base = rc_dev->base + 0x40;
> +       else
> +               rc_dev->rx_base = rc_dev->base;
> +
> +       rc_dev->dev = dev;
> +       platform_set_drvdata(pdev, rc_dev);
> +       st_rc_hardware_init(rc_dev);
> +
> +       rdev->driver_type = RC_DRIVER_IR_RAW;
> +       rdev->allowed_protos = RC_BIT_ALL;
> +       /* rx sampling rate is 10Mhz */
> +       rdev->rx_resolution = 100;
> +       rdev->timeout = US_TO_NS(MAX_SYMB_TIME);
> +       rdev->priv = rc_dev;
> +       rdev->open = st_rc_open;
> +       rdev->close = st_rc_close;
> +       rdev->driver_name = IR_ST_NAME;
> +       rdev->map_name = RC_MAP_LIRC;
> +       rdev->input_name = "ST Remote Control Receiver";
> +
> +       /* enable wake via this device */
> +       device_set_wakeup_capable(dev, true);
> +       device_set_wakeup_enable(dev, true);
> +
> +       ret = rc_register_device(rdev);
> +       if (ret < 0)
> +               goto clkerr;
> +
> +       rc_dev->rdev = rdev;
> +       if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt,
> +                       IRQF_NO_SUSPEND, IR_ST_NAME, rc_dev) < 0) {
> +               dev_err(dev, "IRQ %d register failed\n", rc_dev->irq);
> +               ret = -EINVAL;
> +               goto rcerr;
> +       }
> +
> +       /**
> +        * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW
> +        * lircd expects a long space first before a signal train to sync.
> +        */
> +       st_rc_send_lirc_timeout(rdev);
> +
> +       dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR");
> +
> +       return ret;
> +rcerr:
> +       rc_unregister_device(rdev);
> +       rdev = NULL;
> +clkerr:
> +       clk_disable_unprepare(rc_dev->sys_clock);
> +err:
> +       rc_free_device(rdev);
> +       dev_err(dev, "Unable to register device (%d)\n", ret);
> +       return ret;
> +}
> +
> +#ifdef CONFIG_PM
> +static int st_rc_suspend(struct device *dev)
> +{
> +       struct st_rc_device *rc_dev = dev_get_drvdata(dev);
> +
> +       if (device_may_wakeup(dev)) {
> +               if (!enable_irq_wake(rc_dev->irq))
> +                       rc_dev->irq_wake = 1;
> +               else
> +                       return -EINVAL;
> +       } else {
> +               pinctrl_pm_select_sleep_state(dev);
> +               writel(0x00, rc_dev->rx_base + IRB_RX_EN);
> +               writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
> +               clk_disable_unprepare(rc_dev->sys_clock);
> +       }
> +
> +       return 0;
> +}
> +
> +static int st_rc_resume(struct device *dev)
> +{
> +       struct st_rc_device *rc_dev = dev_get_drvdata(dev);
> +       struct rc_dev   *rdev = rc_dev->rdev;
> +
> +       if (rc_dev->irq_wake) {
> +               disable_irq_wake(rc_dev->irq);
> +               rc_dev->irq_wake = 0;
> +       } else {
> +               pinctrl_pm_select_default_state(dev);
> +               st_rc_hardware_init(rc_dev);
> +               if (rdev->users) {
> +                       writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN);
> +                       writel(0x01, rc_dev->rx_base + IRB_RX_EN);
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume);
> +#endif
> +
> +#ifdef CONFIG_OF
> +static struct of_device_id st_rc_match[] = {
> +       { .compatible = "st,comms-irb", },
> +       {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, st_rc_match);
> +#endif
> +
> +static struct platform_driver st_rc_driver = {
> +       .driver = {
> +               .name = IR_ST_NAME,
> +               .owner  = THIS_MODULE,
> +               .of_match_table = of_match_ptr(st_rc_match),
> +#ifdef CONFIG_PM
> +               .pm     = &st_rc_pm_ops,
> +#endif
> +       },
> +       .probe = st_rc_probe,
> +       .remove = st_rc_remove,
> +};
> +
> +module_platform_driver(st_rc_driver);
> +
> +MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");
> +MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");
> +MODULE_LICENSE("GPL");
> --
> 1.7.6.5
> 
> 
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Re: [PATCH v3] media: st-rc: Add ST remote control driver

[Srinivas KANDAGATLA]

Thanks Mark,

On 16/09/13 15:10, Mark Rutland wrote:
>> +
>> > +Required properties:
>> > +       - compatible: should be "st,comms-irb".
> This should probably say "should contain" rather than "should be". There
> may be future vairants of this device, which will also have a more
> specific compatible string.
Ok, will change it to the suggest.
> 
>> > +       - reg: base physical address of the controller and length of memory
>> > +       mapped  region.
>> > +       - interrupts: interrupt number to the cpu. The interrupt specifier
>> > +       format depends on the interrupt controller parent.
> I don't like the phrase "interrupt number to the cpu". We already have
> the term interrupt-specifier to precisely define this. How about:
> 
> - interrupts: interrupt-specifier for the sole interrupt generated by
>               the device.
> 
TBH, I did copy them from one of the existing bindings docs.
I will change it.
>> > +
>> > +Optional properties:
>> > +       - rx-mode: can be "infrared" or "uhf".
>> > +       - tx-mode: should be "infrared".
> Are these required to use rx/tx?
Yes, these are required for driver to be in rx/tx mode.

One of them can be optional depending on the board setup.
So, Is it ok to move such properties to required properties section?
> 
> If you don't have a tx-mode or rx-mode, I assume you can't do
> anything...
Yes, driver errs out.
> 
>> > +       - pinctrl-names, pinctrl-0: the pincontrol settings to configure
>> > +       muxing properly for IRB pins.
> If we're expecting names, the names we expect should be defined.
> 
>> > +       - clocks : phandle of clock.
> This is not just a phandle. This is a phandle + clock-specifier pair.
Yep, will change it.

Thanks,
srini
> 
> Cheers,

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Re: [PATCH v3] media: st-rc: Add ST remote control driver

[Mark Rutland]

On Wed, Sep 18, 2013 at 11:11:29AM +0100, Srinivas KANDAGATLA wrote:
> Thanks Mark,
> 
> On 16/09/13 15:10, Mark Rutland wrote:
> >> +
> >> > +Required properties:
> >> > +       - compatible: should be "st,comms-irb".
> > This should probably say "should contain" rather than "should be". There
> > may be future vairants of this device, which will also have a more
> > specific compatible string.
> Ok, will change it to the suggest.
> > 
> >> > +       - reg: base physical address of the controller and length of memory
> >> > +       mapped  region.
> >> > +       - interrupts: interrupt number to the cpu. The interrupt specifier
> >> > +       format depends on the interrupt controller parent.
> > I don't like the phrase "interrupt number to the cpu". We already have
> > the term interrupt-specifier to precisely define this. How about:
> > 
> > - interrupts: interrupt-specifier for the sole interrupt generated by
> >               the device.
> > 
> TBH, I did copy them from one of the existing bindings docs.
> I will change it.

There's a lot of inconsistency with existing docs, it would be nice to
use consistent, correct terminology going forward :)

> >> > +
> >> > +Optional properties:
> >> > +       - rx-mode: can be "infrared" or "uhf".
> >> > +       - tx-mode: should be "infrared".
> > Are these required to use rx/tx?
> Yes, these are required for driver to be in rx/tx mode.
> 
> One of them can be optional depending on the board setup.
> So, Is it ok to move such properties to required properties section?

I'd probably just make a note on each stating what they mean (i.e. that
rx-mode should be present iff the rx pins are wired up).

> > 
> > If you don't have a tx-mode or rx-mode, I assume you can't do
> > anything...
> Yes, driver errs out.
> > 
> >> > +       - pinctrl-names, pinctrl-0: the pincontrol settings to configure
> >> > +       muxing properly for IRB pins.
> > If we're expecting names, the names we expect should be defined.
> > 
> >> > +       - clocks : phandle of clock.
> > This is not just a phandle. This is a phandle + clock-specifier pair.
> Yep, will change it.

Cheers.

Mark.
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