From b9270dc07b1b66cce33580bca6276c20f1bf68d2 Mon Sep 17 00:00:00 2001
From: Steve Sakoman <steve@sakoman.com>
Date: Wed, 19 Jan 2011 16:06:42 +0100
Subject: [PATCH 19/45] drivers: mfd: add twl4030 madc driver

---
 drivers/mfd/Kconfig        |   21 ++
 drivers/mfd/Makefile       |    1 +
 drivers/mfd/twl4030-madc.c |  536 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 558 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mfd/twl4030-madc.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 306b346..6221146 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -148,6 +148,27 @@ config TWL4030_CODEC
 	default n
 
 
+config TWL4030_MADC
+	tristate "TWL4030 MADC Driver"
+	depends on TWL4030_CORE
+	help
+	  The TWL4030 Monitoring ADC driver enables the host
+	  processor to monitor analog signals using analog-to-digital
+	  conversions on the input source. TWL4030 MADC provides the
+	  following features:
+	   - Single 10-bit ADC with successive approximation register (SAR) conversion;
+	   - Analog multiplexer for 16 inputs;
+	   - Seven (of the 16) inputs are freely available;
+	   - Battery voltage monitoring;
+	   - Concurrent conversion request management;
+	   - Interrupt signal to Primary Interrupt Handler;
+	   - Averaging feature;
+	   - Selective enable/disable of the averaging feature.
+
+	  Say 'y' here to statically link this module into the kernel or 'm'
+	  to build it as a dinamically loadable module. The module will be
+	  called twl4030-madc.ko
+
 config MFD_TMIO
 	bool
 	default n
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 85dc3a7..44350e7 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_MENELAUS)		+= menelaus.o
 obj-$(CONFIG_TWL4030_CORE)	+= twl-core.o twl4030-irq.o twl6030-irq.o
 obj-$(CONFIG_TWL4030_POWER)    += twl4030-power.o
 obj-$(CONFIG_TWL4030_CODEC)	+= twl4030-codec.o
+obj-$(CONFIG_TWL4030_MADC)	+= twl4030-madc.o
 
 obj-$(CONFIG_TPS65910_CORE)     += tps65910-core.o
 
diff --git a/drivers/mfd/twl4030-madc.c b/drivers/mfd/twl4030-madc.c
new file mode 100644
index 0000000..7d83ab8
--- /dev/null
+++ b/drivers/mfd/twl4030-madc.c
@@ -0,0 +1,536 @@
+/*
+ * TWL4030 MADC module driver
+ *
+ * Copyright (C) 2008 Nokia Corporation
+ * Mikko Ylinen <mikko.k.ylinen@nokia.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/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/platform_device.h>
+#include <linux/miscdevice.h>
+#include <linux/i2c/twl4030.h>
+#include <linux/i2c/twl4030-madc.h>
+
+#include <asm/uaccess.h>
+
+#define TWL4030_MADC_PFX	"twl4030-madc: "
+
+struct twl4030_madc_data {
+	struct device		*dev;
+	struct mutex		lock;
+	struct work_struct	ws;
+	struct twl4030_madc_request	requests[TWL4030_MADC_NUM_METHODS];
+	int imr;
+	int isr;
+};
+
+static struct twl4030_madc_data *the_madc;
+
+static
+const struct twl4030_madc_conversion_method twl4030_conversion_methods[] = {
+	[TWL4030_MADC_RT] = {
+		.sel	= TWL4030_MADC_RTSELECT_LSB,
+		.avg	= TWL4030_MADC_RTAVERAGE_LSB,
+		.rbase	= TWL4030_MADC_RTCH0_LSB,
+	},
+	[TWL4030_MADC_SW1] = {
+		.sel	= TWL4030_MADC_SW1SELECT_LSB,
+		.avg	= TWL4030_MADC_SW1AVERAGE_LSB,
+		.rbase	= TWL4030_MADC_GPCH0_LSB,
+		.ctrl	= TWL4030_MADC_CTRL_SW1,
+	},
+	[TWL4030_MADC_SW2] = {
+		.sel	= TWL4030_MADC_SW2SELECT_LSB,
+		.avg	= TWL4030_MADC_SW2AVERAGE_LSB,
+		.rbase	= TWL4030_MADC_GPCH0_LSB,
+		.ctrl	= TWL4030_MADC_CTRL_SW2,
+	},
+};
+
+static int twl4030_madc_read(struct twl4030_madc_data *madc, u8 reg)
+{
+	int ret;
+	u8 val;
+
+	ret = twl4030_i2c_read_u8(TWL4030_MODULE_MADC, &val, reg);
+	if (ret) {
+		dev_dbg(madc->dev, "unable to read register 0x%X\n", reg);
+		return ret;
+	}
+
+	return val;
+}
+
+static void twl4030_madc_write(struct twl4030_madc_data *madc, u8 reg, u8 val)
+{
+	int ret;
+
+	ret = twl4030_i2c_write_u8(TWL4030_MODULE_MADC, val, reg);
+	if (ret)
+		dev_err(madc->dev, "unable to write register 0x%X\n", reg);
+}
+
+static int twl4030_madc_channel_raw_read(struct twl4030_madc_data *madc, u8 reg)
+{
+	u8 msb, lsb;
+
+	/* For each ADC channel, we have MSB and LSB register pair. MSB address
+	 * is always LSB address+1. reg parameter is the addr of LSB register */
+	msb = twl4030_madc_read(madc, reg + 1);
+	lsb = twl4030_madc_read(madc, reg);
+
+	return (int)(((msb << 8) | lsb) >> 6);
+}
+
+static int twl4030_madc_read_channels(struct twl4030_madc_data *madc,
+		u8 reg_base, u16 channels, int *buf)
+{
+	int count = 0;
+	u8 reg, i;
+
+	if (unlikely(!buf))
+		return 0;
+
+	for (i = 0; i < TWL4030_MADC_MAX_CHANNELS; i++) {
+		if (channels & (1<<i)) {
+			reg = reg_base + 2*i;
+			buf[i] = twl4030_madc_channel_raw_read(madc, reg);
+			count++;
+		}
+	}
+	return count;
+}
+
+static void twl4030_madc_enable_irq(struct twl4030_madc_data *madc, int id)
+{
+	u8 val;
+
+	val = twl4030_madc_read(madc, madc->imr);
+	val &= ~(1 << id);
+	twl4030_madc_write(madc, madc->imr, val);
+}
+
+static void twl4030_madc_disable_irq(struct twl4030_madc_data *madc, int id)
+{
+	u8 val;
+
+	val = twl4030_madc_read(madc, madc->imr);
+	val |= (1 << id);
+	twl4030_madc_write(madc, madc->imr, val);
+}
+
+static irqreturn_t twl4030_madc_irq_handler(int irq, void *_madc)
+{
+	struct twl4030_madc_data *madc = _madc;
+	u8 isr_val, imr_val;
+	int i;
+
+#ifdef CONFIG_LOCKDEP
+	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
+	 * we don't want and can't tolerate.  Although it might be
+	 * friendlier not to borrow this thread context...
+	 */
+	local_irq_enable();
+#endif
+
+	/* Use COR to ack interrupts since we have no shared IRQs in ISRx */
+	isr_val = twl4030_madc_read(madc, madc->isr);
+	imr_val = twl4030_madc_read(madc, madc->imr);
+
+	isr_val &= ~imr_val;
+
+	for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
+
+		if (!(isr_val & (1<<i)))
+			continue;
+
+		twl4030_madc_disable_irq(madc, i);
+		madc->requests[i].result_pending = 1;
+	}
+
+	schedule_work(&madc->ws);
+
+	return IRQ_HANDLED;
+}
+
+static void twl4030_madc_work(struct work_struct *ws)
+{
+	const struct twl4030_madc_conversion_method *method;
+	struct twl4030_madc_data *madc;
+	struct twl4030_madc_request *r;
+	int len, i;
+
+	madc = container_of(ws, struct twl4030_madc_data, ws);
+	mutex_lock(&madc->lock);
+
+	for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
+
+		r = &madc->requests[i];
+
+		/* No pending results for this method, move to next one */
+		if (!r->result_pending)
+			continue;
+
+		method = &twl4030_conversion_methods[r->method];
+
+		/* Read results */
+		len = twl4030_madc_read_channels(madc, method->rbase,
+						 r->channels, r->rbuf);
+
+		/* Return results to caller */
+		if (r->func_cb != NULL) {
+			r->func_cb(len, r->channels, r->rbuf);
+			r->func_cb = NULL;
+		}
+
+		/* Free request */
+		r->result_pending = 0;
+		r->active	  = 0;
+	}
+
+	mutex_unlock(&madc->lock);
+}
+
+static int twl4030_madc_set_irq(struct twl4030_madc_data *madc,
+		struct twl4030_madc_request *req)
+{
+	struct twl4030_madc_request *p;
+
+	p = &madc->requests[req->method];
+
+	memcpy(p, req, sizeof *req);
+
+	twl4030_madc_enable_irq(madc, req->method);
+
+	return 0;
+}
+
+static inline void twl4030_madc_start_conversion(struct twl4030_madc_data *madc,
+		int conv_method)
+{
+	const struct twl4030_madc_conversion_method *method;
+
+	method = &twl4030_conversion_methods[conv_method];
+
+	switch (conv_method) {
+	case TWL4030_MADC_SW1:
+	case TWL4030_MADC_SW2:
+		twl4030_madc_write(madc, method->ctrl, TWL4030_MADC_SW_START);
+		break;
+	case TWL4030_MADC_RT:
+	default:
+		break;
+	}
+}
+
+static int twl4030_madc_wait_conversion_ready(
+		struct twl4030_madc_data *madc,
+		unsigned int timeout_ms, u8 status_reg)
+{
+	unsigned long timeout;
+
+	timeout = jiffies + msecs_to_jiffies(timeout_ms);
+	do {
+		u8 reg;
+
+		reg = twl4030_madc_read(madc, status_reg);
+		if (!(reg & TWL4030_MADC_BUSY) && (reg & TWL4030_MADC_EOC_SW))
+			return 0;
+	} while (!time_after(jiffies, timeout));
+
+	return -EAGAIN;
+}
+
+int twl4030_madc_conversion(struct twl4030_madc_request *req)
+{
+	const struct twl4030_madc_conversion_method *method;
+	u8 ch_msb, ch_lsb;
+	int ret;
+
+	if (unlikely(!req))
+		return -EINVAL;
+
+	mutex_lock(&the_madc->lock);
+
+	/* Do we have a conversion request ongoing */
+	if (the_madc->requests[req->method].active) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	ch_msb = (req->channels >> 8) & 0xff;
+	ch_lsb = req->channels & 0xff;
+
+	method = &twl4030_conversion_methods[req->method];
+
+	/* Select channels to be converted */
+	twl4030_madc_write(the_madc, method->sel + 1, ch_msb);
+	twl4030_madc_write(the_madc, method->sel, ch_lsb);
+
+	/* Select averaging for all channels if do_avg is set */
+	if (req->do_avg) {
+		twl4030_madc_write(the_madc, method->avg + 1, ch_msb);
+		twl4030_madc_write(the_madc, method->avg, ch_lsb);
+	}
+
+	if ((req->type == TWL4030_MADC_IRQ_ONESHOT) && (req->func_cb != NULL)) {
+		twl4030_madc_set_irq(the_madc, req);
+		twl4030_madc_start_conversion(the_madc, req->method);
+		the_madc->requests[req->method].active = 1;
+		ret = 0;
+		goto out;
+	}
+
+	/* With RT method we should not be here anymore */
+	if (req->method == TWL4030_MADC_RT) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	twl4030_madc_start_conversion(the_madc, req->method);
+	the_madc->requests[req->method].active = 1;
+
+	/* Wait until conversion is ready (ctrl register returns EOC) */
+	ret = twl4030_madc_wait_conversion_ready(the_madc, 5, method->ctrl);
+	if (ret) {
+		dev_dbg(the_madc->dev, "conversion timeout!\n");
+		the_madc->requests[req->method].active = 0;
+		goto out;
+	}
+
+	ret = twl4030_madc_read_channels(the_madc, method->rbase, req->channels,
+					 req->rbuf);
+
+	the_madc->requests[req->method].active = 0;
+
+out:
+	mutex_unlock(&the_madc->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(twl4030_madc_conversion);
+
+static int twl4030_madc_set_current_generator(struct twl4030_madc_data *madc,
+		int chan, int on)
+{
+	int ret;
+	u8 regval;
+
+	/* Current generator is only available for ADCIN0 and ADCIN1. NB:
+	 * ADCIN1 current generator only works when AC or VBUS is present */
+	if (chan > 1)
+		return EINVAL;
+
+	ret = twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE,
+				  &regval, TWL4030_BCI_BCICTL1);
+	if (on)
+		regval |= (chan) ? TWL4030_BCI_ITHEN : TWL4030_BCI_TYPEN;
+	else
+		regval &= (chan) ? ~TWL4030_BCI_ITHEN : ~TWL4030_BCI_TYPEN;
+	ret = twl4030_i2c_write_u8(TWL4030_MODULE_MAIN_CHARGE,
+				   regval, TWL4030_BCI_BCICTL1);
+
+	return ret;
+}
+
+static int twl4030_madc_set_power(struct twl4030_madc_data *madc, int on)
+{
+	u8 regval;
+
+	regval = twl4030_madc_read(madc, TWL4030_MADC_CTRL1);
+	if (on)
+		regval |= TWL4030_MADC_MADCON;
+	else
+		regval &= ~TWL4030_MADC_MADCON;
+	twl4030_madc_write(madc, TWL4030_MADC_CTRL1, regval);
+
+	return 0;
+}
+
+static long twl4030_madc_ioctl(struct file *filp, unsigned int cmd,
+			       unsigned long arg)
+{
+	struct twl4030_madc_user_parms par;
+	int val, ret;
+
+	ret = copy_from_user(&par, (void __user *) arg, sizeof(par));
+	if (ret) {
+		dev_dbg(the_madc->dev, "copy_from_user: %d\n", ret);
+		return -EACCES;
+	}
+
+	switch (cmd) {
+	case TWL4030_MADC_IOCX_ADC_RAW_READ: {
+		struct twl4030_madc_request req;
+		if (par.channel >= TWL4030_MADC_MAX_CHANNELS)
+			return -EINVAL;
+
+		req.channels = (1 << par.channel);
+		req.do_avg	= par.average;
+		req.method	= TWL4030_MADC_SW1;
+		req.func_cb	= NULL;
+
+		val = twl4030_madc_conversion(&req);
+		if (val <= 0) {
+			par.status = -1;
+		} else {
+			par.status = 0;
+			par.result = (u16)req.rbuf[par.channel];
+		}
+		break;
+					     }
+	default:
+		return -EINVAL;
+	}
+
+	ret = copy_to_user((void __user *) arg, &par, sizeof(par));
+	if (ret) {
+		dev_dbg(the_madc->dev, "copy_to_user: %d\n", ret);
+		return -EACCES;
+	}
+
+	return 0;
+}
+
+static struct file_operations twl4030_madc_fileops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = twl4030_madc_ioctl
+};
+
+static struct miscdevice twl4030_madc_device = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "twl4030-madc",
+	.fops = &twl4030_madc_fileops
+};
+
+static int __init twl4030_madc_probe(struct platform_device *pdev)
+{
+	struct twl4030_madc_data *madc;
+	struct twl4030_madc_platform_data *pdata = pdev->dev.platform_data;
+	int ret;
+	u8 regval;
+
+	madc = kzalloc(sizeof *madc, GFP_KERNEL);
+	if (!madc)
+		return -ENOMEM;
+
+	if (!pdata) {
+		dev_dbg(&pdev->dev, "platform_data not available\n");
+		ret = -EINVAL;
+		goto err_pdata;
+	}
+
+	madc->imr = (pdata->irq_line == 1) ? TWL4030_MADC_IMR1 : TWL4030_MADC_IMR2;
+	madc->isr = (pdata->irq_line == 1) ? TWL4030_MADC_ISR1 : TWL4030_MADC_ISR2;
+
+	ret = misc_register(&twl4030_madc_device);
+	if (ret) {
+		dev_dbg(&pdev->dev, "could not register misc_device\n");
+		goto err_misc;
+	}
+	twl4030_madc_set_power(madc, 1);
+	twl4030_madc_set_current_generator(madc, 0, 1);
+
+	/* Enable ADCIN3 through 6 */
+	ret = twl4030_i2c_read_u8(TWL4030_MODULE_USB,
+				  &regval, TWL4030_USB_CARKIT_ANA_CTRL);
+
+	regval |= TWL4030_USB_SEL_MADC_MCPC;
+
+	ret = twl4030_i2c_write_u8(TWL4030_MODULE_USB,
+				regval, TWL4030_USB_CARKIT_ANA_CTRL);
+
+
+	ret = twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE,
+				  &regval, TWL4030_BCI_BCICTL1);
+
+	regval |= TWL4030_BCI_MESBAT;
+
+	ret = twl4030_i2c_write_u8(TWL4030_MODULE_MAIN_CHARGE,
+				   regval, TWL4030_BCI_BCICTL1);
+
+	ret = request_irq(platform_get_irq(pdev, 0), twl4030_madc_irq_handler,
+			  0, "twl4030_madc", madc);
+	if (ret) {
+		dev_dbg(&pdev->dev, "could not request irq\n");
+		goto err_irq;
+	}
+
+	platform_set_drvdata(pdev, madc);
+	mutex_init(&madc->lock);
+	INIT_WORK(&madc->ws, twl4030_madc_work);
+
+	the_madc = madc;
+
+	return 0;
+
+err_irq:
+	misc_deregister(&twl4030_madc_device);
+
+err_misc:
+err_pdata:
+	kfree(madc);
+
+	return ret;
+}
+
+static int __exit twl4030_madc_remove(struct platform_device *pdev)
+{
+	struct twl4030_madc_data *madc = platform_get_drvdata(pdev);
+
+	twl4030_madc_set_power(madc, 0);
+	twl4030_madc_set_current_generator(madc, 0, 0);
+	free_irq(platform_get_irq(pdev, 0), madc);
+	cancel_work_sync(&madc->ws);
+	misc_deregister(&twl4030_madc_device);
+
+	return 0;
+}
+
+static struct platform_driver twl4030_madc_driver = {
+	.probe		= twl4030_madc_probe,
+	.remove		= __exit_p(twl4030_madc_remove),
+	.driver		= {
+		.name	= "twl4030_madc",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init twl4030_madc_init(void)
+{
+	return platform_driver_register(&twl4030_madc_driver);
+}
+module_init(twl4030_madc_init);
+
+static void __exit twl4030_madc_exit(void)
+{
+	platform_driver_unregister(&twl4030_madc_driver);
+}
+module_exit(twl4030_madc_exit);
+
+MODULE_ALIAS("platform:twl4030-madc");
+MODULE_AUTHOR("Nokia Corporation");
+MODULE_DESCRIPTION("twl4030 ADC driver");
+MODULE_LICENSE("GPL");
+
-- 
1.6.6.1

