[PATCH] mfd: ab8500-gpadc Add new GPADC driver

From: Arun Murthy
Date: Thu Jan 20 2011 - 06:02:38 EST


AB8500 GPADC driver used to convert Acc and battery/ac/usb voltage

Signed-off-by: Arun Murthy <arun.murthy@xxxxxxxxxxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
---
drivers/mfd/Kconfig | 7 +
drivers/mfd/Makefile | 1 +
drivers/mfd/ab8500-gpadc.c | 277 ++++++++++++++++++++++++++++++++++++++
include/linux/mfd/ab8500-gpadc.h | 47 +++++++
include/linux/mfd/ab8500.h | 6 +
5 files changed, 338 insertions(+), 0 deletions(-)
create mode 100644 drivers/mfd/ab8500-gpadc.c
create mode 100644 include/linux/mfd/ab8500-gpadc.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index fd01836..5309534 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -523,6 +523,13 @@ config AB8500_DEBUG
Select this option if you want debug information using the debug
filesystem, debugfs.

+config AB8500_GPADC
+ bool "AB8500 GPADC driver"
+ depends on AB8500_CORE && REGULATOR_AB8500
+ default y
+ help
+ AB8500 GPADC driver used to convert Acc and battery/ac/usb voltage
+
config AB3550_CORE
bool "ST-Ericsson AB3550 Mixed Signal Circuit core functions"
select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index a54e2c7..c17ab3f 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -73,6 +73,7 @@ obj-$(CONFIG_AB3550_CORE) += ab3550-core.o
obj-$(CONFIG_AB8500_CORE) += ab8500-core.o
obj-$(CONFIG_AB8500_I2C_CORE) += ab8500-i2c.o
obj-$(CONFIG_AB8500_DEBUG) += ab8500-debugfs.o
+obj-$(CONFIG_AB8500_GPADC) += ab8500-gpadc.o
obj-$(CONFIG_MFD_TIMBERDALE) += timberdale.o
obj-$(CONFIG_PMIC_ADP5520) += adp5520.o
obj-$(CONFIG_LPC_SCH) += lpc_sch.o
diff --git a/drivers/mfd/ab8500-gpadc.c b/drivers/mfd/ab8500-gpadc.c
new file mode 100644
index 0000000..b2113db
--- /dev/null
+++ b/drivers/mfd/ab8500-gpadc.c
@@ -0,0 +1,277 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ * Author: Arun R Murthy <arun.murthy@xxxxxxxxxxxxxx>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/completion.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/mfd/ab8500.h>
+#include <linux/mfd/abx500.h>
+#include <linux/mfd/ab8500-gpadc.h>
+
+/*
+ * GPADC register offsets
+ * Bank : 0x0A
+ */
+#define AB8500_GPADC_CTRL1_REG 0x00
+#define AB8500_GPADC_CTRL2_REG 0x01
+#define AB8500_GPADC_CTRL3_REG 0x02
+#define AB8500_GPADC_AUTO_TIMER_REG 0x03
+#define AB8500_GPADC_STAT_REG 0x04
+#define AB8500_GPADC_MANDATAL_REG 0x05
+#define AB8500_GPADC_MANDATAH_REG 0x06
+#define AB8500_GPADC_AUTODATAL_REG 0x07
+#define AB8500_GPADC_AUTODATAH_REG 0x08
+#define AB8500_GPADC_MUX_CTRL_REG 0x09
+
+/* gpadc constants */
+#define EN_VINTCORE12 0x04
+#define EN_VTVOUT 0x02
+#define EN_GPADC 0x01
+#define DIS_GPADC 0x00
+#define SW_AVG_16 0x60
+#define ADC_SW_CONV 0x04
+#define EN_BUF 0x40
+#define DIS_ZERO 0x00
+#define GPADC_BUSY 0x01
+
+/**
+ * ab8500_gpadc_convert() - gpadc conversion
+ * @input: analog input to be converted to digital data
+ *
+ * This function converts the selected analog i/p to digital
+ * data. Thereafter calibration has to be made to obtain the
+ * data in the required quantity measurement.
+ */
+int ab8500_gpadc_convert(struct ab8500_gpadc *di, u8 input)
+{
+ int ret;
+ u16 data = 0;
+ int looplimit = 0;
+ u8 val, low_data, high_data;
+
+ if (!di)
+ return -ENODEV;
+
+ mutex_lock(&di->ab8500_gpadc_lock);
+ /* Enable VTVout LDO this is required for GPADC */
+ regulator_enable(di->regu);
+
+ /* Check if ADC is not busy, lock and proceed */
+ do {
+ ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_STAT_REG, &val);
+ if (ret < 0)
+ goto out;
+ if (!(val & GPADC_BUSY))
+ break;
+ msleep(10);
+ } while (++looplimit < 10);
+ if (looplimit >= 10 && (val & GPADC_BUSY)) {
+ dev_err(di->dev, "gpadc_conversion: GPADC busy");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Enable GPADC */
+ ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
+ if (ret < 0) {
+ dev_err(di->dev, "gpadc_conversion: enable gpadc failed\n");
+ goto out;
+ }
+ /* Select the input source and set average samples to 16 */
+ ret = abx500_set_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16));
+ if (ret < 0) {
+ dev_err(di->dev,
+ "gpadc_conversion: set avg samples failed\n");
+ goto out;
+ }
+ /* Enable ADC, Buffering and select rising edge, start Conversion */
+ ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
+ if (ret < 0) {
+ dev_err(di->dev,
+ "gpadc_conversion: select falling edge failed\n");
+ goto out;
+ }
+ ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
+ if (ret < 0) {
+ dev_err(di->dev,
+ "gpadc_conversion: start s/w conversion failed\n");
+ goto out;
+ }
+ /* wait for completion of conversion */
+ if (!wait_for_completion_timeout(&di->ab8500_gpadc_complete, 2*HZ)) {
+ dev_err(di->dev,
+ "timeout: didnt recieve GPADC conversion interrupt\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Read the converted RAW data */
+ ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_MANDATAL_REG, &low_data);
+ if (ret < 0) {
+ dev_err(di->dev, "gpadc_conversion: read low data failed\n");
+ goto out;
+ }
+
+ ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_MANDATAH_REG, &high_data);
+ if (ret < 0) {
+ dev_err(di->dev, "gpadc_conversion: read high data failed\n");
+ goto out;
+ }
+
+ data = (high_data << 8) | low_data;
+ /* Disable GPADC */
+ ret = abx500_set_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_CTRL1_REG, DIS_GPADC);
+ if (ret < 0) {
+ dev_err(di->dev, "gpadc_conversion: disable gpadc failed\n");
+ goto out;
+ }
+ /* Disable VTVout LDO this is required for GPADC */
+ regulator_disable(di->regu);
+ mutex_unlock(&di->ab8500_gpadc_lock);
+ return data;
+
+out:
+ /*
+ * It has shown to be needed to turn off the GPADC if an error occurs,
+ * otherwise we might have problem when waiting for the busy bit in the
+ * GPADC status register to go low. In V1.1 there wait_for_completion
+ * seems to timeout when waiting for an interrupt.. Not seen in V2.0
+ */
+ (void) abx500_set_register_interruptible(di->dev, AB8500_GPADC,
+ AB8500_GPADC_CTRL1_REG, DIS_GPADC);
+ regulator_disable(di->regu);
+ mutex_unlock(&di->ab8500_gpadc_lock);
+ dev_err(di->dev, "gpadc_conversion: Failed to AD convert channel %d\n",
+ input);
+ return ret;
+}
+EXPORT_SYMBOL(ab8500_gpadc_convert);
+
+/**
+ * ab8500_bm_gpswadcconvend_handler() - isr for s/w gpadc conversion completion
+ * @irq: irq number
+ * @data: pointer to the data passed during request irq
+ *
+ * This is a interrupt service routine for s/w gpadc conversion completion.
+ * Notifies the gpadc completion is completed and the converted raw value
+ * can be read from the registers.
+ * Returns IRQ status(IRQ_HANDLED)
+ */
+static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_di)
+{
+ struct ab8500_gpadc *di = _di;
+
+ complete(&di->ab8500_gpadc_complete);
+
+ return IRQ_HANDLED;
+}
+
+static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
+{
+ int ret = 0;
+ struct ab8500_gpadc *di;
+
+ di = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
+ if (!di) {
+ dev_err(&pdev->dev, "Error: No memory\n");
+ return -ENOMEM;
+ }
+
+ di->parent = dev_get_drvdata(pdev->dev.parent);
+ di->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
+ if (di->irq < 0) {
+ dev_err(di->dev, "failed to get platform irq-%d\n", di->irq);
+ ret = di->irq;
+ goto fail;
+ }
+
+ di->dev = &pdev->dev;
+ mutex_init(&di->ab8500_gpadc_lock);
+
+ /* Initialize completion used to notify completion of conversion */
+ init_completion(&di->ab8500_gpadc_complete);
+
+ /* Register interrupt - SwAdcComplete */
+ ret = request_threaded_irq(di->irq, NULL,
+ ab8500_bm_gpswadcconvend_handler,
+ IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc", di);
+ if (ret < 0) {
+ dev_err(di->dev, "Failed to register interrupt, irq: %d\n",
+ di->irq);
+ goto fail;
+ }
+
+ /* VTVout LDO used to power up ab8500-GPADC */
+ di->regu = regulator_get(&pdev->dev, "vddadc");
+ if (IS_ERR(di->regu)) {
+ ret = PTR_ERR(di->regu);
+ dev_err(di->dev, "failed to get vtvout LDO\n");
+ goto fail;
+ }
+ di->parent->gpadc = di;
+ dev_dbg(di->dev, "probe success\n");
+ return 0;
+fail:
+ kfree(di);
+ di = NULL;
+ return ret;
+}
+
+static int __devexit ab8500_gpadc_remove(struct platform_device *pdev)
+{
+ struct ab8500_gpadc *di = platform_get_drvdata(pdev);
+
+ /* remove interrupt - completion of Sw ADC conversion */
+ free_irq(di->irq, di);
+ /* disable VTVout LDO that is being used by GPADC */
+ regulator_put(di->regu);
+ kfree(di);
+ di = NULL;
+ return 0;
+}
+
+static struct platform_driver ab8500_gpadc_driver = {
+ .probe = ab8500_gpadc_probe,
+ .remove = __devexit_p(ab8500_gpadc_remove),
+ .driver = {
+ .name = "ab8500-gpadc",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init ab8500_gpadc_init(void)
+{
+ return platform_driver_register(&ab8500_gpadc_driver);
+}
+
+static void __exit ab8500_gpadc_exit(void)
+{
+ platform_driver_unregister(&ab8500_gpadc_driver);
+}
+
+subsys_initcall_sync(ab8500_gpadc_init);
+module_exit(ab8500_gpadc_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Arun R Murthy");
+MODULE_ALIAS("platform:ab8500_gpadc");
+MODULE_DESCRIPTION("AB8500 GPADC driver");
diff --git a/include/linux/mfd/ab8500-gpadc.h b/include/linux/mfd/ab8500-gpadc.h
new file mode 100644
index 0000000..1b0adbb
--- /dev/null
+++ b/include/linux/mfd/ab8500-gpadc.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2010 ST-Ericsson SA
+ * Licensed under GPLv2.
+ *
+ * Author: Arun R Murthy <arun.murthy@xxxxxxxxxxxxxx>
+ */
+
+#ifndef _AB8500_GPADC_H
+#define _AB8500_GPADC_H
+
+/* GPADC source: From datasheet(ADCSwSel[4:0] in GPADCCtrl2) */
+#define BAT_CTRL 0x01
+#define BTEMP_BALL 0x02
+#define MAIN_CHARGER_V 0x03
+#define ACC_DETECT1 0x04
+#define ACC_DETECT2 0x05
+#define ADC_AUX1 0x06
+#define ADC_AUX2 0x07
+#define MAIN_BAT_V 0x08
+#define VBUS_V 0x09
+#define MAIN_CHARGER_C 0x0A
+#define USB_CHARGER_C 0x0B
+#define BK_BAT_V 0x0C
+#define DIE_TEMP 0x0D
+
+/**
+ * struct ab8500_gpadc - ab8500 GPADC device information
+ * @dev: pointer to the struct device
+ * @parent: pointer to the parent device structure ab8500
+ * @ab8500_gpadc_complete: pointer to the struct completion, to indicate
+ * the completion of gpadc conversion
+ * @ab8500_gpadc_lock: structure of type mutex
+ * @regu: pointer to the struct regulator
+ * @irq: interrupt number that is used by gpadc
+ */
+struct ab8500_gpadc {
+ struct device *dev;
+ struct ab8500 *parent;
+ struct completion ab8500_gpadc_complete;
+ struct mutex ab8500_gpadc_lock;
+ struct regulator *regu;
+ int irq;
+};
+
+int ab8500_gpadc_convert(struct ab8500_gpadc *di, u8 input);
+
+#endif /* _AB8500_GPADC_H */
diff --git a/include/linux/mfd/ab8500.h b/include/linux/mfd/ab8500.h
index 37f56b7..8ebc4d8 100644
--- a/include/linux/mfd/ab8500.h
+++ b/include/linux/mfd/ab8500.h
@@ -106,6 +106,9 @@
#define AB8500_NR_IRQS 112
#define AB8500_NUM_IRQ_REGS 14

+/* Forward Declaration */
+struct ab8500_gpadc;
+
/**
* struct ab8500 - ab8500 internal structure
* @dev: parent device
@@ -119,6 +122,7 @@
* @tx_buf: tx buf for SPI
* @mask: cache of IRQ regs for bus lock
* @oldmask: cache of previous IRQ regs for bus lock
+ * @gpadc: pointer to the ab8500 gpadc device information
*/
struct ab8500 {
struct device *dev;
@@ -137,6 +141,8 @@ struct ab8500 {

u8 mask[AB8500_NUM_IRQ_REGS];
u8 oldmask[AB8500_NUM_IRQ_REGS];
+
+ struct ab8500_gpadc *gpadc;
};

struct regulator_init_data;
--
1.7.2.dirty

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