mfd: TWL6030: add ADC driver

This driver takes the TWL4030 ADC driver as a template and implements
the ability to fetch a result from any channel on the mux.  It does
not implement the other features in the TWL4030 ADC driver.

Change-Id: If9150b2386e2c11754f40b1de7b28f1680a5730e
Signed-off-by: Marty Fouts <mfouts@sta.samsung.com>

4 files changed, 358 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 5a067aa..8206646 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -237,6 +237,16 @@ config TWL6030_POWEROFF
 	bool "TWL6030 device poweroff"
 	depends on TWL4030_CORE
 
+config TWL6030_MADC
+	tristate "Texas Instruments TWL6030 MADC"
+	depends on TWL4030_CORE
+	help
+	This driver provides support for TWL6030-MADC. The
+	driver supports both RT and SW conversion methods.
+
+	This driver can be built as a module. If so it will be
+	named twl6030-madc
+
 config TWL6040_CODEC
 	bool
 	depends on TWL4030_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 0b3517a..5a4688f 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_TWL4030_MADC)      += twl4030-madc.o
 obj-$(CONFIG_TWL4030_POWER)    += twl4030-power.o
 obj-$(CONFIG_TWL4030_CODEC)	+= twl4030-codec.o
 obj-$(CONFIG_TWL6030_PWM)	+= twl6030-pwm.o
+obj-$(CONFIG_TWL6030_MADC)	+= twl6030-madc.o
 obj-$(CONFIG_TWL6040_CODEC)	+= twl6040-codec.o twl6040-irq.o
 obj-$(CONFIG_TWL6030_POWEROFF)	+= twl6030-poweroff.o
 
diff --git a/drivers/mfd/twl6030-madc.c b/drivers/mfd/twl6030-madc.c
new file mode 100644
index 0000000..b1dcf30
--- /dev/null
+++ b/drivers/mfd/twl6030-madc.c
@@ -0,0 +1,261 @@
+/*
+ *
+ * TWL6030 MADC module driver-This driver only implements the ADC read
+ * functions
+ *
+ * Copyright (C) 2011 Samsung Telecommunications of America
+ *
+ * Based on twl4030-madc.c
+ * Copyright (C) 2008 Nokia Corporation
+ * Mikko Ylinen <mikko.k.ylinen@nokia.com>
+ *
+ * Amit Kucheria <amit.kucheria@canonical.com>
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/i2c/twl.h>
+#include <linux/i2c/twl6030-madc.h>
+#include <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/mutex.h>
+#include <linux/bitops.h>
+#include <linux/jiffies.h>
+#include <linux/types.h>
+#include <linux/gfp.h>
+#include <linux/err.h>
+
+#define GPADCS		(1 << 1)
+#define REG_TOGGLE1	0x90
+
+/*
+ * struct twl6030_madc_data - a container for madc info
+ * @dev - pointer to device structure for madc
+ * @lock - mutex protecting this data structure
+ */
+struct twl6030_madc_data {
+	struct device *dev;
+	struct mutex lock;
+};
+
+static struct twl6030_madc_data *twl6030_madc;
+
+static inline int twl6030_madc_start_conversion(struct twl6030_madc_data *madc)
+{
+	int ret;
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, GPADCS, REG_TOGGLE1);
+	if (ret) {
+		dev_err(madc->dev, "unable to write register 0x%X\n",
+			REG_TOGGLE1);
+		return ret;
+	}
+
+	ret = twl_i2c_write_u8(TWL_MODULE_MADC, TWL6030_MADC_SP2,
+				TWL6030_MADC_CTRL_P2);
+	if (ret) {
+		dev_err(madc->dev, "unable to write register 0x%X\n",
+			TWL6030_MADC_CTRL_P2);
+		return ret;
+	}
+	return 0;
+}
+
+/*
+ * Function that waits for conversion to be ready
+ * @madc - pointer to twl4030_madc_data struct
+ * @timeout_ms - timeout value in milliseconds
+ * @status_reg - ctrl register
+ * returns 0 if succeeds else a negative error value
+ */
+static int twl6030_madc_wait_conversion_ready(struct twl6030_madc_data *madc,
+					      unsigned int timeout_ms,
+					      u8 status_reg)
+{
+	unsigned long timeout;
+	int ret;
+
+	timeout = jiffies + msecs_to_jiffies(timeout_ms);
+	do {
+		u8 reg;
+
+		ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &reg, status_reg);
+		if (ret) {
+			dev_err(madc->dev,
+				"unable to read status register 0x%X\n",
+				status_reg);
+			return ret;
+		}
+		if (!(reg & TWL6030_MADC_BUSY) && (reg & TWL6030_MADC_EOCP1))
+			return 0;
+		usleep_range(500, 2000);
+	} while (!time_after(jiffies, timeout));
+	dev_err(madc->dev, "conversion timeout!\n");
+
+	return -EAGAIN;
+}
+
+/*
+ * Function to read a particular channel value.
+ * @madc - pointer to struct twl6030_madc_data
+ * @reg - lsb of ADC Channel
+ * If the i2c read fails it returns an error else returns 0.
+ */
+static int twl6030_madc_channel_raw_read(struct twl6030_madc_data *madc,
+					u8 reg)
+{
+	u8 msb, lsb;
+	int ret;
+	u8 ctrl_p1;
+
+	mutex_lock(&madc->lock);
+	ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &ctrl_p1,
+			TWL6030_MADC_CTRL_P1);
+	if (ret) {
+		dev_err(madc->dev, "unable to read control register.");
+		goto unlock;
+	}
+
+	if ((ctrl_p1 & TWL6030_MADC_CTRL_P1) != TWL6030_MADC_CTRL_P1) {
+		ctrl_p1 |= TWL6030_MADC_SP1;
+		ret = twl_i2c_write_u8(TWL6030_MODULE_MADC, ctrl_p1,
+				TWL6030_MADC_CTRL_P1);
+		if (ret) {
+			dev_err(madc->dev,
+				"unable to write control register.");
+			goto unlock;
+		}
+	}
+
+	(void)twl6030_madc_start_conversion(twl6030_madc);
+	ret = twl6030_madc_wait_conversion_ready(twl6030_madc, 5,
+						TWL6030_MADC_CTRL_P1);
+	if (ret)
+		goto unlock;
+
+	/*
+	 * For each ADC channel, we have MSB and LSB register
+	 * pair. MSB address is always LSB address+1. reg parameter is
+	 * the address of LSB register
+	 */
+	ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &msb, reg + 1);
+	if (ret) {
+		dev_err(madc->dev, "unable to read MSB register 0x%X\n",
+			reg + 1);
+		goto unlock;
+	}
+	ret = twl_i2c_read_u8(TWL6030_MODULE_MADC, &lsb, reg);
+	if (ret) {
+		dev_err(madc->dev, "unable to read LSB register 0x%X\n", reg);
+		goto unlock;
+	}
+	ret = (int)((msb << 8) | lsb);
+unlock:
+	mutex_unlock(&madc->lock);
+	return ret;
+}
+
+/*
+ * Return channel value
+ * Or < 0 on failure.
+ */
+int twl6030_get_madc_conversion(int channel_no)
+{
+	u8 reg = TWL6030_MADC_GPCH0_LSB + (2 * channel_no);
+	if (!twl6030_madc) {
+		pr_err("%s: No ADC device\n", __func__);
+		return -EINVAL;
+	}
+	if (channel_no >= TWL6030_MADC_MAX_CHANNELS) {
+		dev_err(twl6030_madc->dev,
+			"%s: Channel number (%d) exceeds max (%d)\n",
+			__func__, channel_no, TWL6030_MADC_MAX_CHANNELS);
+		return -EINVAL;
+	}
+
+	return twl6030_madc_channel_raw_read(twl6030_madc, reg);
+}
+EXPORT_SYMBOL_GPL(twl6030_get_madc_conversion);
+
+/*
+ * Initialize MADC
+ */
+static int __devinit twl6030_madc_probe(struct platform_device *pdev)
+{
+	struct twl6030_madc_data *madc;
+	struct twl4030_madc_platform_data *pdata = pdev->dev.platform_data;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "platform_data not available\n");
+		return -EINVAL;
+	}
+	madc = kzalloc(sizeof(*madc), GFP_KERNEL);
+	if (!madc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, madc);
+	mutex_init(&madc->lock);
+	twl6030_madc = madc;
+	return 0;
+}
+
+static int __devexit twl6030_madc_remove(struct platform_device *pdev)
+{
+	struct twl6030_madc_data *madc = platform_get_drvdata(pdev);
+
+	mutex_destroy(&madc->lock);
+	free_irq(platform_get_irq(pdev, 0), madc);
+	platform_set_drvdata(pdev, NULL);
+	twl6030_madc = NULL;
+	kfree(madc);
+
+	return 0;
+}
+
+static struct platform_driver twl6030_madc_driver = {
+	.probe = twl6030_madc_probe,
+	.remove = __exit_p(twl6030_madc_remove),
+	.driver = {
+		   .name = "twl6030_madc",
+		   .owner = THIS_MODULE,
+		   },
+};
+
+static int __init twl6030_madc_init(void)
+{
+	return platform_driver_register(&twl6030_madc_driver);
+}
+
+module_init(twl6030_madc_init);
+
+static void __exit twl6030_madc_exit(void)
+{
+	platform_driver_unregister(&twl6030_madc_driver);
+}
+
+module_exit(twl6030_madc_exit);
+
+MODULE_DESCRIPTION("TWL6030 ADC driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("J Keerthy");
+MODULE_ALIAS("platform:twl6030_madc");
diff --git a/include/linux/i2c/twl6030-madc.h b/include/linux/i2c/twl6030-madc.h
new file mode 100644
index 0000000..81b9464
--- /dev/null
+++ b/include/linux/i2c/twl6030-madc.h
@@ -0,0 +1,86 @@
+/*
+ * twl6030_madc.h - Header for TWL6030 MADC
+ *
+ * Copyright (C) 2011 Samsung Telecommunications of America
+ *
+ * Based on twl4030-madc.h
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
+ * J Keerthy <j-keerthy@ti.com>
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#ifndef _TWL6030_MADC_H
+#define _TWL6030_MADC_H
+
+#define TWL6030_MADC_MAX_CHANNELS 17
+/*
+ * twl6030 madc occupies the same offset in the twl6030 map that
+ * twl4030 madc does in the twl4030 map.
+ * likewise the charger
+ */
+#define TWL6030_MODULE_MADC          TWL4030_MODULE_MADC
+#define TWL6030_MODULE_MAIN_CHARGE   TWL4030_MODULE_MAIN_CHARGE
+
+#define TWL6030_MADC_CTRL		0x00
+#define    TWL6030_MADC_TEMP1_EN        (1 << 0)
+#define    TWL6030_MADC_TEMP2_EN        (1 << 1)
+#define    TWL6030_MADC_SCALER_EN_CH2	(1 << 2)
+#define    TWL6030_MADC_VBAT_SCALER_DIV	(1 << 3)
+#define    TWL6030_MADC_SCALER_EN_CH11	(1 << 4)
+#define    TWL6030_MADC_TMP1_EN_MONITOR	(1 << 5)
+#define    TWL6030_MADC_TMP2_EN_MONITOR	(1 << 6)
+#define    TWL6030_MADC_ISOURCE_EN	(1 << 7)
+
+#define TWL6030_MADC_RTSELECT_LSB	0x02
+#define    TWL6030_MADC_ADCIN0	(1 << 0)
+#define    TWL6030_MADC_ADCIN1	(1 << 1)
+#define    TWL6030_MADC_ADCIN2	(1 << 2)
+#define    TWL6030_MADC_ADCIN3	(1 << 3)
+#define    TWL6030_MADC_ADCIN4	(1 << 4)
+#define    TWL6030_MADC_ADCIN5	(1 << 5)
+#define    TWL6030_MADC_ADCIN6	(1 << 6)
+#define    TWL6030_MADC_ADCIN7	(1 << 7)
+
+#define TWL6030_MADC_RTSELECT_ISB	0x03
+#define    TWL6030_MADC_ADCIN8		(1 << 0)
+#define    TWL6030_MADC_ADCIN9		(1 << 1)
+#define    TWL6030_MADC_ADCIN10		(1 << 2)
+#define    TWL6030_MADC_ADCIN11		(1 << 3)
+#define    TWL6030_MADC_ADCIN12		(1 << 4)
+#define    TWL6030_MADC_ADCIN13		(1 << 5)
+#define    TWL6030_MADC_ADCIN14		(1 << 6)
+#define    TWL6030_MADC_ADCIN15		(1 << 7)
+
+#define TWL6030_MADC_RTSELECT_MSB	0x04
+#define    TWL6030_MADC_ADCIN16		(1 << 0)
+
+#define TWL6030_MADC_CTRL_P1		0x05
+#define    TWL6030_MADC_BUSY		(1 << 0)
+#define    TWL6030_MADC_EOCP1		(1 << 1)
+#define    TWL6030_MADC_EOCRT		(1 << 2)
+#define    TWL6030_MADC_SP1		(1 << 3)
+
+#define TWL6030_MADC_CTRL_P2		0x06
+#define    TWL6030_MADC_BUSYB		(1 << 0)
+#define    TWL6030_MADC_EOCP2		(1 << 1)
+#define    TWL6030_MADC_SP2		(1 << 2)
+
+#define TWL6030_MADC_RTCH0_LSB		0x07
+#define TWL6030_MADC_GPCH0_LSB		0x29
+
+int twl6030_get_madc_conversion(int channel_no);
+#endif