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>

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 0000000..19339bc
--- /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");