[RFC][PATCH 22/26] hwmon: Add JZ4740 ADC driver

[Lars-Peter Clausen <lars@metafoo.de>]

This patch adds support for the ADC module on JZ4740 SoCs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: lm-sensors@lm-sensors.org
---
 drivers/hwmon/Kconfig      |   11 ++
 drivers/hwmon/Makefile     |    1 +
 drivers/hwmon/jz4740-adc.c |  423 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/jz4740-adc.h |   25 +++
 4 files changed, 460 insertions(+), 0 deletions(-)
 create mode 100644 drivers/hwmon/jz4740-adc.c
 create mode 100644 include/linux/jz4740-adc.h

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index e19cf8e..da79ba9 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -446,6 +446,17 @@ config SENSORS_IT87
 	  This driver can also be built as a module.  If so, the module
 	  will be called it87.
 
+config SENSORS_JZ4740
+	tristate "Ingenic JZ4740 SoC ADC driver"
+	depends on MACH_JZ4740
+    help
+      If you say yes here you get support for the Ingenic JZ4740 SoC ADC core.
+      It is required for the JZ4740 battery and touchscreen driver and is used
+      to synchronize access to the adc module between those two.
+
+      This driver can also be build as a module. If so, the module will be
+      called jz4740-adc.
+
 config SENSORS_LM63
 	tristate "National Semiconductor LM63 and LM64"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 2138ceb..3e772aa 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
 obj-$(CONFIG_SENSORS_IBMAEM)	+= ibmaem.o
 obj-$(CONFIG_SENSORS_IBMPEX)	+= ibmpex.o
 obj-$(CONFIG_SENSORS_IT87)	+= it87.o
+obj-$(CONFIG_SENSORS_JZ4740)	+= jz4740-adc.o
 obj-$(CONFIG_SENSORS_K8TEMP)	+= k8temp.o
 obj-$(CONFIG_SENSORS_K10TEMP)	+= k10temp.o
 obj-$(CONFIG_SENSORS_LIS3LV02D) += lis3lv02d.o hp_accel.o
diff --git a/drivers/hwmon/jz4740-adc.c b/drivers/hwmon/jz4740-adc.c
new file mode 100644
index 0000000..635dfe9
--- /dev/null
+++ b/drivers/hwmon/jz4740-adc.c
@@ -0,0 +1,423 @@
+/*
+ * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
+ *		JZ4740 SoC ADC driver
+ *
+ * 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.
+ *
+ * You should have received a copy of the  GNU General Public License along
+ * with this program; if not, write  to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * This driver is meant to synchronize access to the adc core for the battery
+ * and touchscreen driver. Thus these drivers should use the adc driver as a
+ * parent.
+ */
+
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+
+#include <linux/clk.h>
+
+#include <linux/jz4740-adc.h>
+
+#define JZ_REG_ADC_ENABLE	0x00
+#define JZ_REG_ADC_CFG		0x04
+#define JZ_REG_ADC_CTRL		0x08
+#define JZ_REG_ADC_STATUS	0x0C
+#define JZ_REG_ADC_SAME		0x10
+#define JZ_REG_ADC_WAIT		0x14
+#define JZ_REG_ADC_TOUCH	0x18
+#define JZ_REG_ADC_BATTERY	0x1C
+#define JZ_REG_ADC_ADCIN	0x20
+
+#define JZ_ADC_ENABLE_TOUCH		BIT(2)
+#define JZ_ADC_ENABLE_BATTERY		BIT(1)
+#define JZ_ADC_ENABLE_ADCIN		BIT(0)
+
+#define JZ_ADC_CFG_SPZZ			BIT(31)
+#define JZ_ADC_CFG_EX_IN		BIT(30)
+#define JZ_ADC_CFG_DNUM_MASK		(0x7 << 16)
+#define JZ_ADC_CFG_DMA_ENABLE		BIT(15)
+#define JZ_ADC_CFG_XYZ_MASK		(0x2 << 13)
+#define JZ_ADC_CFG_SAMPLE_NUM_MASK	(0x7 << 10)
+#define JZ_ADC_CFG_CLKDIV		(0xf << 5)
+#define JZ_ADC_CFG_BAT_MB		BIT(4)
+
+#define JZ_ADC_CFG_DNUM_OFFSET		16
+#define JZ_ADC_CFG_XYZ_OFFSET		13
+#define JZ_ADC_CFG_SAMPLE_NUM_OFFSET	10
+#define JZ_ADC_CFG_CLKDIV_OFFSET	5
+
+#define JZ_ADC_IRQ_PENDOWN		BIT(4)
+#define JZ_ADC_IRQ_PENUP		BIT(3)
+#define JZ_ADC_IRQ_TOUCH		BIT(2)
+#define JZ_ADC_IRQ_BATTERY		BIT(1)
+#define JZ_ADC_IRQ_ADCIN		BIT(0)
+
+#define JZ_ADC_TOUCH_TYPE1		BIT(31)
+#define JZ_ADC_TOUCH_DATA1_MASK		0xfff
+#define JZ_ADC_TOUCH_TYPE0		BIT(15)
+#define JZ_ADC_TOUCH_DATA0_MASK		0xfff
+
+#define JZ_ADC_BATTERY_MASK		0xfff
+
+#define JZ_ADC_ADCIN_MASK		0xfff
+
+struct jz4740_adc {
+	struct resource *mem;
+	void __iomem *base;
+
+	int irq;
+
+	struct clk *clk;
+	unsigned int clk_ref;
+
+	struct device *hwmon;
+
+	struct completion bat_completion;
+	struct completion adc_completion;
+
+	spinlock_t lock;
+};
+
+static irqreturn_t jz4740_adc_irq(int irq, void *data)
+{
+	struct jz4740_adc *adc = data;
+	uint8_t status;
+
+	status = readb(adc->base + JZ_REG_ADC_STATUS);
+
+	if (status & JZ_ADC_IRQ_BATTERY)
+		complete(&adc->bat_completion);
+	if (status & JZ_ADC_IRQ_ADCIN)
+		complete(&adc->adc_completion);
+
+	writeb(0xff, adc->base + JZ_REG_ADC_STATUS);
+
+	return IRQ_HANDLED;
+}
+
+static void jz4740_adc_enable_irq(struct jz4740_adc *adc, int irq)
+{
+	unsigned long flags;
+	uint8_t val;
+
+	spin_lock_irqsave(&adc->lock, flags);
+
+	val = readb(adc->base + JZ_REG_ADC_CTRL);
+	val &= ~irq;
+	writeb(val, adc->base + JZ_REG_ADC_CTRL);
+
+	spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+static void jz4740_adc_disable_irq(struct jz4740_adc *adc, int irq)
+{
+	unsigned long flags;
+	uint8_t val;
+
+	spin_lock_irqsave(&adc->lock, flags);
+
+	val = readb(adc->base + JZ_REG_ADC_CTRL);
+	val |= irq;
+	writeb(val, adc->base + JZ_REG_ADC_CTRL);
+
+	spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+static void jz4740_adc_enable_adc(struct jz4740_adc *adc, int engine)
+{
+	unsigned long flags;
+	uint8_t val;
+
+	spin_lock_irqsave(&adc->lock, flags);
+
+	val = readb(adc->base + JZ_REG_ADC_ENABLE);
+	val |= engine;
+	writeb(val, adc->base + JZ_REG_ADC_ENABLE);
+
+	spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+static void jz4740_adc_disable_adc(struct jz4740_adc *adc, int engine)
+{
+	unsigned long flags;
+	uint8_t val;
+
+	spin_lock_irqsave(&adc->lock, flags);
+
+	val = readb(adc->base + JZ_REG_ADC_ENABLE);
+	val &= ~engine;
+	writeb(val, adc->base + JZ_REG_ADC_ENABLE);
+
+	spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+static inline void jz4740_adc_set_cfg(struct jz4740_adc *adc, uint32_t mask,
+uint32_t val)
+{
+	unsigned long flags;
+	uint32_t cfg;
+
+	spin_lock_irqsave(&adc->lock, flags);
+
+	cfg = readl(adc->base + JZ_REG_ADC_CFG);
+
+	cfg &= ~mask;
+	cfg |= val;
+
+	writel(cfg, adc->base + JZ_REG_ADC_CFG);
+
+	spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&adc->lock, flags);
+	if (adc->clk_ref++ == 0)
+		clk_enable(adc->clk);
+	spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&adc->lock, flags);
+	if (--adc->clk_ref == 0)
+		clk_disable(adc->clk);
+	spin_unlock_irqrestore(&adc->lock, flags);
+}
+
+long jz4740_adc_read_battery_voltage(struct device *dev,
+						enum jz_adc_battery_scale scale)
+{
+	struct jz4740_adc *adc = dev_get_drvdata(dev);
+	unsigned long t;
+	long long voltage;
+	uint16_t val;
+
+	if (!adc)
+		return -ENODEV;
+
+	jz4740_adc_clk_enable(adc);
+
+	if (scale == JZ_ADC_BATTERY_SCALE_2V5)
+		jz4740_adc_set_cfg(adc, JZ_ADC_CFG_BAT_MB, JZ_ADC_CFG_BAT_MB);
+	else
+		jz4740_adc_set_cfg(adc, JZ_ADC_CFG_BAT_MB, 0);
+
+	jz4740_adc_enable_irq(adc, JZ_ADC_IRQ_BATTERY);
+	jz4740_adc_enable_adc(adc, JZ_ADC_ENABLE_BATTERY);
+
+	t = wait_for_completion_interruptible_timeout(&adc->bat_completion,
+							HZ);
+
+	jz4740_adc_disable_irq(adc, JZ_ADC_IRQ_BATTERY);
+
+	if (t <= 0) {
+		jz4740_adc_disable_adc(adc, JZ_ADC_ENABLE_BATTERY);
+		return t ? t : -ETIMEDOUT;
+	}
+
+	val = readw(adc->base + JZ_REG_ADC_BATTERY);
+
+	jz4740_adc_clk_disable(adc);
+
+	if (scale == JZ_ADC_BATTERY_SCALE_2V5)
+		voltage = (((long long)val) * 2500000LL) >> 12LL;
+	else
+		voltage = ((((long long)val) * 7395000LL) >> 12LL) + 33000LL;
+
+	return voltage;
+}
+EXPORT_SYMBOL_GPL(jz4740_adc_read_battery_voltage);
+
+static ssize_t jz4740_adc_read_adcin(struct device *dev,
+					struct device_attribute *dev_attr,
+					char *buf)
+{
+	struct jz4740_adc *adc = dev_get_drvdata(dev);
+	unsigned long t;
+	uint16_t val;
+
+	jz4740_adc_clk_enable(adc);
+
+	jz4740_adc_enable_irq(adc, JZ_ADC_IRQ_ADCIN);
+	jz4740_adc_enable_adc(adc, JZ_ADC_ENABLE_ADCIN);
+
+	t = wait_for_completion_interruptible_timeout(&adc->adc_completion,
+							HZ);
+
+	jz4740_adc_disable_irq(adc, JZ_ADC_IRQ_ADCIN);
+
+	if (t <= 0) {
+		jz4740_adc_disable_adc(adc, JZ_ADC_ENABLE_ADCIN);
+		return t ? t : -ETIMEDOUT;
+	}
+
+	val = readw(adc->base + JZ_REG_ADC_ADCIN);
+	jz4740_adc_clk_disable(adc);
+
+	return sprintf(buf, "%d\n", val);
+}
+
+static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, jz4740_adc_read_adcin, NULL, 0);
+
+static int __devinit jz4740_adc_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct jz4740_adc *adc;
+
+	adc = kmalloc(sizeof(*adc), GFP_KERNEL);
+
+	adc->irq = platform_get_irq(pdev, 0);
+
+	if (adc->irq < 0) {
+		ret = adc->irq;
+		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
+		goto err_free;
+	}
+
+	adc->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (!adc->mem) {
+		ret = -ENOENT;
+		dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
+		goto err_free;
+	}
+
+	adc->mem = request_mem_region(adc->mem->start, resource_size(adc->mem),
+					pdev->name);
+
+	if (!adc->mem) {
+		ret = -EBUSY;
+		dev_err(&pdev->dev, "Failed to request mmio memory region\n");
+		goto err_free;
+	}
+
+	adc->base = ioremap_nocache(adc->mem->start, resource_size(adc->mem));
+
+	if (!adc->base) {
+		ret = -EBUSY;
+		dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
+		goto err_release_mem_region;
+	}
+
+	adc->clk = clk_get(&pdev->dev, "adc");
+
+	if (IS_ERR(adc->clk)) {
+		ret = PTR_ERR(adc->clk);
+		dev_err(&pdev->dev, "Failed to get clock: %d\n", ret);
+		goto err_iounmap;
+	}
+
+	init_completion(&adc->bat_completion);
+	init_completion(&adc->adc_completion);
+
+	spin_lock_init(&adc->lock);
+
+	adc->clk_ref = 0;
+
+	platform_set_drvdata(pdev, adc);
+
+	ret = request_irq(adc->irq, jz4740_adc_irq, 0, pdev->name, adc);
+
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
+		goto err_clk_put;
+	}
+
+	ret = device_create_file(&pdev->dev, &sensor_dev_attr_in0_input.dev_attr);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to create sysfs file: %d\n", ret);
+		goto err_free_irq;
+	}
+
+	adc->hwmon = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(adc->hwmon)) {
+		ret = PTR_ERR(adc->hwmon);
+		goto err_remove_file;
+	}
+
+	writeb(0x00, adc->base + JZ_REG_ADC_ENABLE);
+	writeb(0xff, adc->base + JZ_REG_ADC_CTRL);
+
+	return 0;
+
+err_remove_file:
+	device_remove_file(&pdev->dev, &sensor_dev_attr_in0_input.dev_attr);
+err_free_irq:
+	free_irq(adc->irq, adc);
+err_clk_put:
+	clk_put(adc->clk);
+err_iounmap:
+	platform_set_drvdata(pdev, NULL);
+	iounmap(adc->base);
+err_release_mem_region:
+	release_mem_region(adc->mem->start, resource_size(adc->mem));
+err_free:
+	kfree(adc);
+
+	return ret;
+}
+
+static int __devexit jz4740_adc_remove(struct platform_device *pdev)
+{
+	struct jz4740_adc *adc = platform_get_drvdata(pdev);
+
+	hwmon_device_unregister(adc->hwmon);
+	device_remove_file(&pdev->dev, &sensor_dev_attr_in0_input.dev_attr);
+
+	free_irq(adc->irq, adc);
+
+	iounmap(adc->base);
+	release_mem_region(adc->mem->start, resource_size(adc->mem));
+
+	clk_put(adc->clk);
+
+	platform_set_drvdata(pdev, NULL);
+
+	kfree(adc);
+
+	return 0;
+}
+
+struct platform_driver jz4740_adc_driver = {
+	.probe	= jz4740_adc_probe,
+	.remove = __devexit_p(jz4740_adc_remove),
+	.driver = {
+		.name = "jz4740-adc",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init jz4740_adc_init(void)
+{
+	return platform_driver_register(&jz4740_adc_driver);
+}
+module_init(jz4740_adc_init);
+
+static void __exit jz4740_adc_exit(void)
+{
+	platform_driver_unregister(&jz4740_adc_driver);
+}
+module_exit(jz4740_adc_exit);
+
+MODULE_DESCRIPTION("JZ4740 SoC ADC driver");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:jz4740-adc");
diff --git a/include/linux/jz4740-adc.h b/include/linux/jz4740-adc.h
new file mode 100644
index 0000000..59cfe63
--- /dev/null
+++ b/include/linux/jz4740-adc.h
@@ -0,0 +1,25 @@
+
+#ifndef __LINUX_JZ4740_ADC
+#define __LINUX_JZ4740_ADC
+
+#include <linux/device.h>
+
+enum jz_adc_battery_scale {
+	JZ_ADC_BATTERY_SCALE_2V5, /* Mesures voltages up to 2.5V */
+	JZ_ADC_BATTERY_SCALE_7V5, /* Mesures voltages up to 7.5V */
+};
+
+/*
+ * jz4740_adc_read_battery_voltage - Read battery voltage from the ADC PBAT pin
+ * @dev: Pointer to a jz4740-adc device
+ * @scale: Whether to use 2.5V or 7.5V scale
+ *
+ * Returns: Battery voltage in mircovolts
+ *
+ * Context: Process
+*/
+long jz4740_adc_read_battery_voltage(struct device *dev,
+					enum jz_adc_battery_scale scale);
+
+
+#endif
-- 
1.5.6.5