Input: stmpe-ts - add DT support for stmpe touchscreen

This patch allows the STMPE Touchscreen driver to be successfully probed and
initialised when Device Tree support is enabled. Bindings are mentioned in
Documentation too.

Signed-off-by: Vipul Kumar Samar <vipulkumar.samar@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

2 files changed, 48 insertions, 18 deletions

diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
index b3f75032deac..43e796747f4b 100644
--- a/drivers/input/touchscreen/stmpe-ts.c
+++ b/drivers/input/touchscreen/stmpe-ts.c
@@ -17,6 +17,7 @@
 #include <linux/interrupt.h>
 #include <linux/init.h>
 #include <linux/device.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/input.h>
 #include <linux/slab.h>
@@ -262,11 +263,53 @@ static void stmpe_ts_close(struct input_dev *dev)
                         STMPE_TSC_CTRL_TSC_EN, 0);
 }
 
-static int __devinit stmpe_input_probe(struct platform_device *pdev)
+static void stmpe_ts_get_platform_info(struct platform_device *pdev,
+                                        struct stmpe_touch *ts)
 {
         struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
-        const struct stmpe_platform_data *pdata = stmpe->pdata;
-        const struct stmpe_ts_platform_data *ts_pdata = NULL;
+        struct device_node *np = pdev->dev.of_node;
+        struct stmpe_ts_platform_data *ts_pdata = NULL;
+
+        ts->stmpe = stmpe;
+
+        if (stmpe->pdata && stmpe->pdata->ts) {
+                ts_pdata = stmpe->pdata->ts;
+
+                ts->sample_time = ts_pdata->sample_time;
+                ts->mod_12b = ts_pdata->mod_12b;
+                ts->ref_sel = ts_pdata->ref_sel;
+                ts->adc_freq = ts_pdata->adc_freq;
+                ts->ave_ctrl = ts_pdata->ave_ctrl;
+                ts->touch_det_delay = ts_pdata->touch_det_delay;
+                ts->settling = ts_pdata->settling;
+                ts->fraction_z = ts_pdata->fraction_z;
+                ts->i_drive = ts_pdata->i_drive;
+        } else if (np) {
+                u32 val;
+
+                if (!of_property_read_u32(np, "st,sample-time", &val))
+                        ts->sample_time = val;
+                if (!of_property_read_u32(np, "st,mod-12b", &val))
+                        ts->mod_12b = val;
+                if (!of_property_read_u32(np, "st,ref-sel", &val))
+                        ts->ref_sel = val;
+                if (!of_property_read_u32(np, "st,adc-freq", &val))
+                        ts->adc_freq = val;
+                if (!of_property_read_u32(np, "st,ave-ctrl", &val))
+                        ts->ave_ctrl = val;
+                if (!of_property_read_u32(np, "st,touch-det-delay", &val))
+                        ts->touch_det_delay = val;
+                if (!of_property_read_u32(np, "st,settling", &val))
+                        ts->settling = val;
+                if (!of_property_read_u32(np, "st,fraction-z", &val))
+                        ts->fraction_z = val;
+                if (!of_property_read_u32(np, "st,i-drive", &val))
+                        ts->i_drive = val;
+        }
+}
+
+static int __devinit stmpe_input_probe(struct platform_device *pdev)
+{
         struct stmpe_touch *ts;
         struct input_dev *idev;
         int error;
@@ -285,24 +328,10 @@ static int __devinit stmpe_input_probe(struct platform_device *pdev)
                 return -ENOMEM;
 
         platform_set_drvdata(pdev, ts);
-        ts->stmpe = stmpe;
         ts->idev = idev;
         ts->dev = &pdev->dev;
 
-        if (pdata)
-                ts_pdata = pdata->ts;
-
-        if (ts_pdata) {
-                ts->sample_time = ts_pdata->sample_time;
-                ts->mod_12b = ts_pdata->mod_12b;
-                ts->ref_sel = ts_pdata->ref_sel;
-                ts->adc_freq = ts_pdata->adc_freq;
-                ts->ave_ctrl = ts_pdata->ave_ctrl;
-                ts->touch_det_delay = ts_pdata->touch_det_delay;
-                ts->settling = ts_pdata->settling;
-                ts->fraction_z = ts_pdata->fraction_z;
-                ts->i_drive = ts_pdata->i_drive;
-        }
+        stmpe_ts_get_platform_info(pdev, ts);
 
         INIT_DELAYED_WORK(&ts->work, stmpe_work);
 
diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c
index c94f521f392c..55c7b9531ad4 100644
--- a/drivers/mfd/stmpe.c
+++ b/drivers/mfd/stmpe.c
@@ -411,6 +411,7 @@ static struct resource stmpe_ts_resources[] = {
 
 static struct mfd_cell stmpe_ts_cell = {
         .name           = "stmpe-ts",
+        .of_compatible  = "st,stmpe-ts",
         .resources      = stmpe_ts_resources,
         .num_resources  = ARRAY_SIZE(stmpe_ts_resources),
 };