X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fiio%2Fadc%2Fti_am335x_adc.c;fp=kernel%2Fdrivers%2Fiio%2Fadc%2Fti_am335x_adc.c;h=a0e7161f040c91daca74a469d27ff641be9ea915;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git

diff --git a/kernel/drivers/iio/adc/ti_am335x_adc.c b/kernel/drivers/iio/adc/ti_am335x_adc.c
new file mode 100644
index 000000000..a0e7161f0
--- /dev/null
+++ b/kernel/drivers/iio/adc/ti_am335x_adc.c
@@ -0,0 +1,547 @@
+/*
+ * TI ADC MFD driver
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/iio/iio.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/iio/machine.h>
+#include <linux/iio/driver.h>
+
+#include <linux/mfd/ti_am335x_tscadc.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/kfifo_buf.h>
+
+struct tiadc_device {
+	struct ti_tscadc_dev *mfd_tscadc;
+	int channels;
+	u8 channel_line[8];
+	u8 channel_step[8];
+	int buffer_en_ch_steps;
+	u16 data[8];
+};
+
+static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
+{
+	return readl(adc->mfd_tscadc->tscadc_base + reg);
+}
+
+static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
+					unsigned int val)
+{
+	writel(val, adc->mfd_tscadc->tscadc_base + reg);
+}
+
+static u32 get_adc_step_mask(struct tiadc_device *adc_dev)
+{
+	u32 step_en;
+
+	step_en = ((1 << adc_dev->channels) - 1);
+	step_en <<= TOTAL_STEPS - adc_dev->channels + 1;
+	return step_en;
+}
+
+static u32 get_adc_chan_step_mask(struct tiadc_device *adc_dev,
+		struct iio_chan_spec const *chan)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(adc_dev->channel_step); i++) {
+		if (chan->channel == adc_dev->channel_line[i]) {
+			u32 step;
+
+			step = adc_dev->channel_step[i];
+			/* +1 for the charger */
+			return 1 << (step + 1);
+		}
+	}
+	WARN_ON(1);
+	return 0;
+}
+
+static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan)
+{
+	return 1 << adc_dev->channel_step[chan];
+}
+
+static void tiadc_step_config(struct iio_dev *indio_dev)
+{
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	unsigned int stepconfig;
+	int i, steps = 0;
+
+	/*
+	 * There are 16 configurable steps and 8 analog input
+	 * lines available which are shared between Touchscreen and ADC.
+	 *
+	 * Steps forwards i.e. from 0 towards 16 are used by ADC
+	 * depending on number of input lines needed.
+	 * Channel would represent which analog input
+	 * needs to be given to ADC to digitalize data.
+	 */
+
+	if (iio_buffer_enabled(indio_dev))
+		stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1
+					| STEPCONFIG_MODE_SWCNT;
+	else
+		stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1;
+
+	for (i = 0; i < adc_dev->channels; i++) {
+		int chan;
+
+		chan = adc_dev->channel_line[i];
+		tiadc_writel(adc_dev, REG_STEPCONFIG(steps),
+				stepconfig | STEPCONFIG_INP(chan));
+		tiadc_writel(adc_dev, REG_STEPDELAY(steps),
+				STEPCONFIG_OPENDLY);
+		adc_dev->channel_step[i] = steps;
+		steps++;
+	}
+}
+
+static irqreturn_t tiadc_irq_h(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	unsigned int status, config;
+	status = tiadc_readl(adc_dev, REG_IRQSTATUS);
+
+	/*
+	 * ADC and touchscreen share the IRQ line.
+	 * FIFO0 interrupts are used by TSC. Handle FIFO1 IRQs here only
+	 */
+	if (status & IRQENB_FIFO1OVRRUN) {
+		/* FIFO Overrun. Clear flag. Disable/Enable ADC to recover */
+		config = tiadc_readl(adc_dev, REG_CTRL);
+		config &= ~(CNTRLREG_TSCSSENB);
+		tiadc_writel(adc_dev, REG_CTRL, config);
+		tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1OVRRUN
+				| IRQENB_FIFO1UNDRFLW | IRQENB_FIFO1THRES);
+		tiadc_writel(adc_dev, REG_CTRL, (config | CNTRLREG_TSCSSENB));
+		return IRQ_HANDLED;
+	} else if (status & IRQENB_FIFO1THRES) {
+		/* Disable irq and wake worker thread */
+		tiadc_writel(adc_dev, REG_IRQCLR, IRQENB_FIFO1THRES);
+		return IRQ_WAKE_THREAD;
+	}
+
+	return IRQ_NONE;
+}
+
+static irqreturn_t tiadc_worker_h(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	int i, k, fifo1count, read;
+	u16 *data = adc_dev->data;
+
+	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
+	for (k = 0; k < fifo1count; k = k + i) {
+		for (i = 0; i < (indio_dev->scan_bytes)/2; i++) {
+			read = tiadc_readl(adc_dev, REG_FIFO1);
+			data[i] = read & FIFOREAD_DATA_MASK;
+		}
+		iio_push_to_buffers(indio_dev, (u8 *) data);
+	}
+
+	tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES);
+	tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_FIFO1THRES);
+
+	return IRQ_HANDLED;
+}
+
+static int tiadc_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	int i, fifo1count, read;
+
+	tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
+				IRQENB_FIFO1OVRRUN |
+				IRQENB_FIFO1UNDRFLW));
+
+	/* Flush FIFO. Needed in corner cases in simultaneous tsc/adc use */
+	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
+	for (i = 0; i < fifo1count; i++)
+		read = tiadc_readl(adc_dev, REG_FIFO1);
+
+	return 0;
+}
+
+static int tiadc_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	unsigned int enb = 0;
+	u8 bit;
+
+	tiadc_step_config(indio_dev);
+	for_each_set_bit(bit, indio_dev->active_scan_mask, adc_dev->channels)
+		enb |= (get_adc_step_bit(adc_dev, bit) << 1);
+	adc_dev->buffer_en_ch_steps = enb;
+
+	am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb);
+
+	tiadc_writel(adc_dev,  REG_IRQSTATUS, IRQENB_FIFO1THRES
+				| IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW);
+	tiadc_writel(adc_dev,  REG_IRQENABLE, IRQENB_FIFO1THRES
+				| IRQENB_FIFO1OVRRUN);
+
+	return 0;
+}
+
+static int tiadc_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	int fifo1count, i, read;
+
+	tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
+				IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW));
+	am335x_tsc_se_clr(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps);
+	adc_dev->buffer_en_ch_steps = 0;
+
+	/* Flush FIFO of leftover data in the time it takes to disable adc */
+	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
+	for (i = 0; i < fifo1count; i++)
+		read = tiadc_readl(adc_dev, REG_FIFO1);
+
+	return 0;
+}
+
+static int tiadc_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	tiadc_step_config(indio_dev);
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops tiadc_buffer_setup_ops = {
+	.preenable = &tiadc_buffer_preenable,
+	.postenable = &tiadc_buffer_postenable,
+	.predisable = &tiadc_buffer_predisable,
+	.postdisable = &tiadc_buffer_postdisable,
+};
+
+static int tiadc_iio_buffered_hardware_setup(struct iio_dev *indio_dev,
+	irqreturn_t (*pollfunc_bh)(int irq, void *p),
+	irqreturn_t (*pollfunc_th)(int irq, void *p),
+	int irq,
+	unsigned long flags,
+	const struct iio_buffer_setup_ops *setup_ops)
+{
+	struct iio_buffer *buffer;
+	int ret;
+
+	buffer = iio_kfifo_allocate();
+	if (!buffer)
+		return -ENOMEM;
+
+	iio_device_attach_buffer(indio_dev, buffer);
+
+	ret = request_threaded_irq(irq,	pollfunc_th, pollfunc_bh,
+				flags, indio_dev->name, indio_dev);
+	if (ret)
+		goto error_kfifo_free;
+
+	indio_dev->setup_ops = setup_ops;
+	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
+
+	return 0;
+
+error_kfifo_free:
+	iio_kfifo_free(indio_dev->buffer);
+	return ret;
+}
+
+static void tiadc_iio_buffered_hardware_remove(struct iio_dev *indio_dev)
+{
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+
+	free_irq(adc_dev->mfd_tscadc->irq, indio_dev);
+	iio_kfifo_free(indio_dev->buffer);
+}
+
+
+static const char * const chan_name_ain[] = {
+	"AIN0",
+	"AIN1",
+	"AIN2",
+	"AIN3",
+	"AIN4",
+	"AIN5",
+	"AIN6",
+	"AIN7",
+};
+
+static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
+{
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	struct iio_chan_spec *chan_array;
+	struct iio_chan_spec *chan;
+	int i;
+
+	indio_dev->num_channels = channels;
+	chan_array = kcalloc(channels,
+			sizeof(struct iio_chan_spec), GFP_KERNEL);
+	if (chan_array == NULL)
+		return -ENOMEM;
+
+	chan = chan_array;
+	for (i = 0; i < channels; i++, chan++) {
+
+		chan->type = IIO_VOLTAGE;
+		chan->indexed = 1;
+		chan->channel = adc_dev->channel_line[i];
+		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+		chan->datasheet_name = chan_name_ain[chan->channel];
+		chan->scan_index = i;
+		chan->scan_type.sign = 'u';
+		chan->scan_type.realbits = 12;
+		chan->scan_type.storagebits = 16;
+	}
+
+	indio_dev->channels = chan_array;
+
+	return 0;
+}
+
+static void tiadc_channels_remove(struct iio_dev *indio_dev)
+{
+	kfree(indio_dev->channels);
+}
+
+static int tiadc_read_raw(struct iio_dev *indio_dev,
+		struct iio_chan_spec const *chan,
+		int *val, int *val2, long mask)
+{
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	int i, map_val;
+	unsigned int fifo1count, read, stepid;
+	bool found = false;
+	u32 step_en;
+	unsigned long timeout;
+
+	if (iio_buffer_enabled(indio_dev))
+		return -EBUSY;
+
+	step_en = get_adc_chan_step_mask(adc_dev, chan);
+	if (!step_en)
+		return -EINVAL;
+
+	fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
+	while (fifo1count--)
+		tiadc_readl(adc_dev, REG_FIFO1);
+
+	am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
+
+	timeout = jiffies + usecs_to_jiffies
+				(IDLE_TIMEOUT * adc_dev->channels);
+	/* Wait for Fifo threshold interrupt */
+	while (1) {
+		fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
+		if (fifo1count)
+			break;
+
+		if (time_after(jiffies, timeout)) {
+			am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
+			return -EAGAIN;
+		}
+	}
+	map_val = adc_dev->channel_step[chan->scan_index];
+
+	/*
+	 * We check the complete FIFO. We programmed just one entry but in case
+	 * something went wrong we left empty handed (-EAGAIN previously) and
+	 * then the value apeared somehow in the FIFO we would have two entries.
+	 * Therefore we read every item and keep only the latest version of the
+	 * requested channel.
+	 */
+	for (i = 0; i < fifo1count; i++) {
+		read = tiadc_readl(adc_dev, REG_FIFO1);
+		stepid = read & FIFOREAD_CHNLID_MASK;
+		stepid = stepid >> 0x10;
+
+		if (stepid == map_val) {
+			read = read & FIFOREAD_DATA_MASK;
+			found = true;
+			*val = (u16) read;
+		}
+	}
+	am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
+
+	if (found == false)
+		return -EBUSY;
+	return IIO_VAL_INT;
+}
+
+static const struct iio_info tiadc_info = {
+	.read_raw = &tiadc_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int tiadc_probe(struct platform_device *pdev)
+{
+	struct iio_dev		*indio_dev;
+	struct tiadc_device	*adc_dev;
+	struct device_node	*node = pdev->dev.of_node;
+	struct property		*prop;
+	const __be32		*cur;
+	int			err;
+	u32			val;
+	int			channels = 0;
+
+	if (!node) {
+		dev_err(&pdev->dev, "Could not find valid DT data.\n");
+		return -EINVAL;
+	}
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev,
+					  sizeof(struct tiadc_device));
+	if (indio_dev == NULL) {
+		dev_err(&pdev->dev, "failed to allocate iio device\n");
+		return -ENOMEM;
+	}
+	adc_dev = iio_priv(indio_dev);
+
+	adc_dev->mfd_tscadc = ti_tscadc_dev_get(pdev);
+
+	of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
+		adc_dev->channel_line[channels] = val;
+		channels++;
+	}
+	adc_dev->channels = channels;
+
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &tiadc_info;
+
+	tiadc_step_config(indio_dev);
+	tiadc_writel(adc_dev, REG_FIFO1THR, FIFO1_THRESHOLD);
+
+	err = tiadc_channel_init(indio_dev, adc_dev->channels);
+	if (err < 0)
+		return err;
+
+	err = tiadc_iio_buffered_hardware_setup(indio_dev,
+		&tiadc_worker_h,
+		&tiadc_irq_h,
+		adc_dev->mfd_tscadc->irq,
+		IRQF_SHARED,
+		&tiadc_buffer_setup_ops);
+
+	if (err)
+		goto err_free_channels;
+
+	err = iio_device_register(indio_dev);
+	if (err)
+		goto err_buffer_unregister;
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	return 0;
+
+err_buffer_unregister:
+	tiadc_iio_buffered_hardware_remove(indio_dev);
+err_free_channels:
+	tiadc_channels_remove(indio_dev);
+	return err;
+}
+
+static int tiadc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	u32 step_en;
+
+	iio_device_unregister(indio_dev);
+	tiadc_iio_buffered_hardware_remove(indio_dev);
+	tiadc_channels_remove(indio_dev);
+
+	step_en = get_adc_step_mask(adc_dev);
+	am335x_tsc_se_clr(adc_dev->mfd_tscadc, step_en);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int tiadc_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	struct ti_tscadc_dev *tscadc_dev;
+	unsigned int idle;
+
+	tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
+	if (!device_may_wakeup(tscadc_dev->dev)) {
+		idle = tiadc_readl(adc_dev, REG_CTRL);
+		idle &= ~(CNTRLREG_TSCSSENB);
+		tiadc_writel(adc_dev, REG_CTRL, (idle |
+				CNTRLREG_POWERDOWN));
+	}
+
+	return 0;
+}
+
+static int tiadc_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	unsigned int restore;
+
+	/* Make sure ADC is powered up */
+	restore = tiadc_readl(adc_dev, REG_CTRL);
+	restore &= ~(CNTRLREG_POWERDOWN);
+	tiadc_writel(adc_dev, REG_CTRL, restore);
+
+	tiadc_step_config(indio_dev);
+	am335x_tsc_se_set_cache(adc_dev->mfd_tscadc,
+			adc_dev->buffer_en_ch_steps);
+	return 0;
+}
+
+static const struct dev_pm_ops tiadc_pm_ops = {
+	.suspend = tiadc_suspend,
+	.resume = tiadc_resume,
+};
+#define TIADC_PM_OPS (&tiadc_pm_ops)
+#else
+#define TIADC_PM_OPS NULL
+#endif
+
+static const struct of_device_id ti_adc_dt_ids[] = {
+	{ .compatible = "ti,am3359-adc", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
+
+static struct platform_driver tiadc_driver = {
+	.driver = {
+		.name   = "TI-am335x-adc",
+		.pm	= TIADC_PM_OPS,
+		.of_match_table = ti_adc_dt_ids,
+	},
+	.probe	= tiadc_probe,
+	.remove	= tiadc_remove,
+};
+module_platform_driver(tiadc_driver);
+
+MODULE_DESCRIPTION("TI ADC controller driver");
+MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
+MODULE_LICENSE("GPL");