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authorArun Murthy <arun.murthy@stericsson.com>2011-02-22 10:11:13 +0100
committerSamuel Ortiz <sameo@linux.intel.com>2011-03-23 10:41:48 +0100
commitdae2db30c114cd0dec59b4130c315c9cce351741 (patch)
treec5c108d1e7635bf086c1bb0b0ce57def0688cce2 /drivers/mfd/ab8500-gpadc.c
parent44bdcb54df2714da18c4a0c6f711a350ab4ed93c (diff)
downloadlinux-dae2db30c114cd0dec59b4130c315c9cce351741.tar.gz
mfd: Add new ab8500 GPADC driver
AB8500 GPADC driver used to convert Acc and battery/ac/usb voltage Signed-off-by: Arun Murthy <arun.murthy@stericsson.com> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Mattias Wallin <mattias.wallin@stericsson.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/mfd/ab8500-gpadc.c')
-rw-r--r--drivers/mfd/ab8500-gpadc.c296
1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/mfd/ab8500-gpadc.c b/drivers/mfd/ab8500-gpadc.c
new file mode 100644
index 00000000000..19339bc439c
--- /dev/null
+++ b/drivers/mfd/ab8500-gpadc.c
@@ -0,0 +1,296 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ * Author: Arun R Murthy <arun.murthy@stericsson.com>
+ */
+#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
+
+/**
+ * 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
+ */
+static struct ab8500_gpadc {
+ struct device *dev;
+ struct ab8500 *parent;
+ struct completion ab8500_gpadc_complete;
+ struct mutex ab8500_gpadc_lock;
+ struct regulator *regu;
+ int irq;
+} *di;
+
+/**
+ * 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(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 *gpadc = _di;
+
+ complete(&gpadc->ab8500_gpadc_complete);
+
+ return IRQ_HANDLED;
+}
+
+static int __devinit ab8500_gpadc_probe(struct platform_device *pdev)
+{
+ int ret = 0;
+ struct ab8500_gpadc *gpadc;
+
+ gpadc = kzalloc(sizeof(struct ab8500_gpadc), GFP_KERNEL);
+ if (!gpadc) {
+ dev_err(&pdev->dev, "Error: No memory\n");
+ return -ENOMEM;
+ }
+
+ gpadc->parent = dev_get_drvdata(pdev->dev.parent);
+ gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
+ if (gpadc->irq < 0) {
+ dev_err(gpadc->dev, "failed to get platform irq-%d\n", di->irq);
+ ret = gpadc->irq;
+ goto fail;
+ }
+
+ gpadc->dev = &pdev->dev;
+ mutex_init(&di->ab8500_gpadc_lock);
+
+ /* Initialize completion used to notify completion of conversion */
+ init_completion(&gpadc->ab8500_gpadc_complete);
+
+ /* Register interrupt - SwAdcComplete */
+ ret = request_threaded_irq(gpadc->irq, NULL,
+ ab8500_bm_gpswadcconvend_handler,
+ IRQF_NO_SUSPEND | IRQF_SHARED, "ab8500-gpadc", gpadc);
+ if (ret < 0) {
+ dev_err(gpadc->dev, "Failed to register interrupt, irq: %d\n",
+ gpadc->irq);
+ goto fail;
+ }
+
+ /* VTVout LDO used to power up ab8500-GPADC */
+ gpadc->regu = regulator_get(&pdev->dev, "vddadc");
+ if (IS_ERR(gpadc->regu)) {
+ ret = PTR_ERR(gpadc->regu);
+ dev_err(gpadc->dev, "failed to get vtvout LDO\n");
+ goto fail;
+ }
+ di = gpadc;
+ dev_dbg(gpadc->dev, "probe success\n");
+ return 0;
+fail:
+ kfree(gpadc);
+ gpadc = NULL;
+ return ret;
+}
+
+static int __devexit ab8500_gpadc_remove(struct platform_device *pdev)
+{
+ struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);
+
+ /* remove interrupt - completion of Sw ADC conversion */
+ free_irq(gpadc->irq, di);
+ /* disable VTVout LDO that is being used by GPADC */
+ regulator_put(gpadc->regu);
+ kfree(gpadc);
+ gpadc = 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");