input: touch: maxim: add device tree support

-update maxim touch driver to support device tree.
-add sample maxim touch device tree in documentation

Bug 1468560

Change-Id: Id7a99ca9bdeb53f7d817e33874dac9bca48965a9
Signed-off-by: Andrew Tran <atran@nvidia.com>
Reviewed-on: http://git-master/r/383999
(cherry picked from commit 86384c3e1db348509887c7bbdbe9f3e3c5be8941)
Reviewed-on: http://git-master/r/383268
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Mitch Luban <mluban@nvidia.com>

1 files changed, 185 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/maxim_sti.c b/drivers/input/touchscreen/maxim_sti.c
index abb91ee42f56..6100bd827ac0 100644
--- a/drivers/input/touchscreen/maxim_sti.c
+++ b/drivers/input/touchscreen/maxim_sti.c
@@ -28,6 +28,12 @@
 #include <linux/regulator/consumer.h>
 #include <linux/maxim_sti.h>
 #include <asm/byteorder.h>  /* MUST include this header to get byte order */
+#ifdef CONFIG_OF
+#include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#endif
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/touchscreen_maxim.h>
@@ -795,6 +801,159 @@ err_null_regulator:
 	dev_warn(&dd->spi->dev, "Failed to init regulators\n");
 }
 
+#ifdef CONFIG_OF
+#define MAXIM_STI_GPIO_ERROR(ret, gpio, op) \
+{ \
+	if (ret < 0) { \
+		pr_err("%s: GPIO %d %s failed (%d)\n", __func__, gpio, op, \
+			ret); \
+		return ret; \
+	} \
+}
+
+
+int maxim_sti_gpio_init(struct maxim_sti_pdata *pdata, bool init)
+{
+	int  ret;
+
+	if (init) {
+		ret = gpio_request(pdata->gpio_irq, "maxim_sti_irq");
+		MAXIM_STI_GPIO_ERROR(ret, pdata->gpio_irq, "request");
+		ret = gpio_direction_input(pdata->gpio_irq);
+		MAXIM_STI_GPIO_ERROR(ret, pdata->gpio_irq, "direction");
+
+		ret = gpio_request(pdata->gpio_reset, "maxim_sti_reset");
+		MAXIM_STI_GPIO_ERROR(ret, pdata->gpio_reset, "request");
+		ret = gpio_direction_output(pdata->gpio_reset,
+					    pdata->default_reset_state);
+		MAXIM_STI_GPIO_ERROR(ret, pdata->gpio_reset, "direction");
+	} else {
+		gpio_free(pdata->gpio_irq);
+		gpio_free(pdata->gpio_reset);
+	}
+
+	return 0;
+}
+
+void maxim_sti_gpio_reset(struct maxim_sti_pdata *pdata, int value)
+{
+	gpio_set_value(pdata->gpio_reset, !!value);
+}
+
+int maxim_sti_gpio_irq(struct maxim_sti_pdata *pdata)
+{
+	return gpio_get_value(pdata->gpio_irq);
+}
+
+/****************************************************************************\
+* Device Tree Support
+\****************************************************************************/
+
+static int maxim_parse_dt(struct device *dev, struct maxim_sti_pdata *pdata)
+{
+	struct device_node *np = dev->of_node;
+	u32 val;
+	const char *str;
+	int ret;
+
+
+	ret = of_property_read_u32(np, "maxim_sti,reset-gpio",
+						 &pdata->gpio_reset);
+	if (ret) {
+		dev_err(dev, "%s: unable to read reset-gpio (%d)\n",
+							__func__, ret);
+		goto fail;
+	}
+
+	ret = of_property_read_u32(np, "interrupts", &pdata->gpio_irq);
+	if (ret) {
+		dev_err(dev, "%s: unable to read irq-gpio (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+
+	ret = of_property_read_u32(np, "maxim_sti,nl_mc_groups", &val);
+	if (ret) {
+		dev_err(dev, "%s: unable to read nl_mc_groups (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+	pdata->nl_mc_groups = (u8)val;
+
+	ret = of_property_read_u32(np, "maxim_sti,chip_access_method", &val);
+	if (ret) {
+		dev_err(dev, "%s: unable to read chip_access_method (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+	pdata->chip_access_method = (u8)val;
+
+	ret = of_property_read_u32(np, "maxim_sti,default_reset_state", &val);
+	if (ret) {
+		dev_err(dev, "%s: unable to read default_reset_state (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+	pdata->default_reset_state = (u8)val;
+
+	ret = of_property_read_u32(np, "maxim_sti,tx_buf_size", &val);
+	if (ret) {
+		dev_err(dev, "%s: unable to read tx_buf_size (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+	pdata->tx_buf_size = (u16)val;
+
+	ret = of_property_read_u32(np, "maxim_sti,rx_buf_size", &val);
+	if (ret) {
+		dev_err(dev, "%s: unable to read rx_buf_size (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+	pdata->rx_buf_size = (u16)val;
+
+	ret = of_property_read_string(np, "maxim_sti,touch_fusion", &str);
+	if (ret) {
+		dev_err(dev, "%s: unable to read touch_fusion location (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+	pdata->touch_fusion = (char *)str;
+
+	ret = of_property_read_string(np, "maxim_sti,config_file", &str);
+	if (ret) {
+		dev_err(dev, "%s: unable to read config_file location (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+	pdata->config_file = (char *)str;
+
+	ret = of_property_read_string(np, "maxim_sti,nl_family", &str);
+	if (ret) {
+		dev_err(dev, "%s: unable to read nl_family (%d)\n",
+								__func__, ret);
+		goto fail;
+	}
+	pdata->nl_family = (char *)str;
+
+	ret = of_property_read_string(np, "maxim_sti,fw_name", &str);
+	if (ret) {
+		dev_err(dev, "%s: unable to read fw_name (%d)\n",
+								__func__, ret);
+	}
+	pdata->fw_name = (char *)str;
+
+	pdata->init = maxim_sti_gpio_init;
+	pdata->reset = maxim_sti_gpio_reset;
+	pdata->irq = maxim_sti_gpio_irq;
+
+	return 0;
+
+fail:
+	return ret;
+}
+#endif
+
 /****************************************************************************\
 * Suspend/resume processing                                                  *
 \****************************************************************************/
@@ -1824,6 +1983,22 @@ static int probe(struct spi_device *spi)
 	int                     ret, i;
 	void                    *ptr;
 
+#ifdef CONFIG_OF
+	if (pdata == NULL && spi->dev.of_node) {
+		pdata = devm_kzalloc(&spi->dev,
+			sizeof(struct maxim_sti_pdata), GFP_KERNEL);
+		if (!pdata) {
+			dev_err(&spi->dev, "failed to allocate memory\n");
+			return -ENOMEM;
+		}
+
+		ret = maxim_parse_dt(&spi->dev, pdata);
+		if (ret)
+			return ret;
+		spi->dev.platform_data = pdata;
+	}
+#endif
+
 	/* validate platform data */
 	if (pdata == NULL || pdata->init == NULL || pdata->reset == NULL ||
 		pdata->irq == NULL || pdata->touch_fusion == NULL ||
@@ -2035,6 +2210,13 @@ static const struct spi_device_id id[] = {
 
 MODULE_DEVICE_TABLE(spi, id);
 
+#ifdef CONFIG_OF
+static struct of_device_id maxim_match_table[] = {
+	{ .compatible = "maxim,maxim_sti",},
+	{ },
+};
+#endif
+
 static struct spi_driver driver = {
 	.probe          = probe,
 	.remove         = remove,
@@ -2042,6 +2224,9 @@ static struct spi_driver driver = {
 	.id_table       = id,
 	.driver = {
 		.name   = MAXIM_STI_NAME,
+#ifdef CONFIG_OF
+		.of_match_table = maxim_match_table,
+#endif
 		.owner  = THIS_MODULE,
 #if defined(CONFIG_PM_SLEEP) && DOUBLE_TAP
 		.pm     = &pm_ops,