[PATCH 05/21] input: ti_am33x_tsc: Add DT support

From: Sebastian Andrzej Siewior
Date: Wed Jun 12 2013 - 12:59:53 EST

From: "Patil, Rachna" <rachna@xxxxxx>

This patch adds DT support to touch driver. It also provides a binding
document which is used by the MFD and IIO part of the device.
This patch also renames steps_to_configure to coordinate_readouts
because the original name misleads the purpose of the variable.

Signed-off-by: Pantelis Antoniou <panto@xxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Patil, Rachna <rachna@xxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
.../bindings/input/touchscreen/ti-tsc-adc.txt | 44 ++++++++
drivers/input/touchscreen/ti_am335x_tsc.c | 105 +++++++++++++++-----
drivers/mfd/ti_am335x_tscadc.c | 1 +
3 files changed, 127 insertions(+), 23 deletions(-)
create mode 100644 Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt

diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
new file mode 100644
index 0000000..491c97b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
@@ -0,0 +1,44 @@
+* TI - TSC ADC (Touschscreen and analog digital converter)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Required properties:
+- child "tsc"
+ ti,wires: Wires refer to application modes i.e. 4/5/8 wire touchscreen
+ support on the platform.
+ ti,x-plate-resistance: X plate resistance
+ ti,coordiante-readouts: The sequencer supports a total of 16
+ programmable steps each step is used to
+ read a single coordinate. A single
+ readout is enough but multiple reads can
+ increase the quality.
+ A value of 5 means, 5 reads for X, 5 for
+ Y and 2 for Z (always). This utilises 12
+ of the 16 software steps available. The
+ remaining 4 can be used by the ADC.
+ ti,wire-config: Different boards could have a different order for
+ connecting wires on touchscreen. We need to provide an
+ 8 bit number where in the 1st four bits represent the
+ analog lines and the next 4 bits represent positive/
+ negative terminal on that input line. Notations to
+ represent the input lines and terminals resoectively
+ is as follows:
+ AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
+ XP = 0, XN = 1, YP = 2, YN = 3.
+- child "adc"
+ ti,adc-channels: List of analog inputs available for ADC.
+ AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
+
+Example:
+ tscadc: tscadc@44e0d000 {
+ compatible = "ti,am3359-tscadc";
+ tsc {
+ ti,wires = <4>;
+ ti,x-plate-resistance = <200>;
+ ti,coordiante-readouts = <5>;
+ ti,wire-config = <0x00 0x11 0x22 0x33>;
+ };
+
+ adc {
+ ti,adc-channels = <4 5 6 7>;
+ };
+ }
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 7b7de60..449c0fb 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -26,6 +26,8 @@
#include <linux/io.h>
#include <linux/input/ti_am335x_tsc.h>
#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_device.h>

#include <linux/mfd/ti_am335x_tscadc.h>

@@ -47,7 +49,7 @@ struct titsc {
unsigned int wires;
unsigned int x_plate_resistance;
bool pen_down;
- int steps_to_configure;
+ int coordinate_readouts;
u32 config_inp[4];
u32 bit_xp, bit_xn, bit_yp, bit_yn;
u32 inp_xp, inp_xn, inp_yp, inp_yn;
@@ -123,7 +125,7 @@ static void titsc_step_config(struct titsc *ts_dev)
int i, total_steps;

/* Configure the Step registers */
- total_steps = 2 * ts_dev->steps_to_configure;
+ total_steps = 2 * ts_dev->coordinate_readouts;

config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_xp;
@@ -141,7 +143,7 @@ static void titsc_step_config(struct titsc *ts_dev)
break;
}

- for (i = 1; i <= ts_dev->steps_to_configure; i++) {
+ for (i = 1; i <= ts_dev->coordinate_readouts; i++) {
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
}
@@ -163,7 +165,7 @@ static void titsc_step_config(struct titsc *ts_dev)
break;
}

- for (i = (ts_dev->steps_to_configure + 1); i <= total_steps; i++) {
+ for (i = (ts_dev->coordinate_readouts + 1); i <= total_steps; i++) {
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
}
@@ -218,7 +220,7 @@ static void titsc_read_coordinates(struct titsc *ts_dev,
read = titsc_readl(ts_dev, REG_FIFO0);
channel = read & 0xf0000;
channel = channel >> 0x10;
- if ((channel >= 0) && (channel < ts_dev->steps_to_configure)) {
+ if ((channel >= 0) && (channel < ts_dev->coordinate_readouts)) {
read &= 0xfff;
diff = abs(read - prev_val_x);
if (diff < prev_diff_x) {
@@ -231,8 +233,8 @@ static void titsc_read_coordinates(struct titsc *ts_dev,
read = titsc_readl(ts_dev, REG_FIFO1);
channel = read & 0xf0000;
channel = channel >> 0x10;
- if ((channel >= ts_dev->steps_to_configure) &&
- (channel < (2 * ts_dev->steps_to_configure - 1))) {
+ if ((channel >= ts_dev->coordinate_readouts) &&
+ (channel < (2 * ts_dev->coordinate_readouts - 1))) {
read &= 0xfff;
diff = abs(read - prev_val_y);
if (diff < prev_diff_y) {
@@ -310,6 +312,59 @@ static irqreturn_t titsc_irq(int irq, void *dev)
return IRQ_HANDLED;
}

+static int titsc_parse_dt(struct platform_device *pdev,
+ struct titsc *ts_dev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ int err;
+
+ if (!node)
+ return -EINVAL;
+
+ err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
+ if (err < 0)
+ return err;
+ switch (ts_dev->wires) {
+ case 4:
+ case 5:
+ case 8:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ err = of_property_read_u32(node, "ti,x-plate-resistance",
+ &ts_dev->x_plate_resistance);
+ if (err < 0)
+ return err;
+
+ err = of_property_read_u32(node, "ti,coordiante-readouts",
+ &ts_dev->coordinate_readouts);
+ if (err < 0)
+ return err;
+
+ return of_property_read_u32_array(node, "ti,wire-config",
+ ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
+}
+
+static int titsc_parse_pdata(struct ti_tscadc_dev *tscadc_dev,
+ struct titsc *ts_dev)
+{
+ struct mfd_tscadc_board *pdata = tscadc_dev->dev->platform_data;
+
+ if (!pdata)
+ return -EINVAL;
+
+ ts_dev->wires = pdata->tsc_init->wires;
+ ts_dev->x_plate_resistance =
+ pdata->tsc_init->x_plate_resistance;
+ ts_dev->steps_to_configure =
+ pdata->tsc_init->steps_to_configure;
+ memcpy(ts_dev->config_inp, pdata->tsc_init->wire_config,
+ sizeof(pdata->tsc_init->wire_config));
+ return 0;
+}
+
/*
* The functions for inserting/removing driver as a module.
*/
@@ -319,16 +374,8 @@ static int titsc_probe(struct platform_device *pdev)
struct titsc *ts_dev;
struct input_dev *input_dev;
struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
- struct mfd_tscadc_board *pdata;
int err;

- pdata = tscadc_dev->dev->platform_data;
-
- if (!pdata) {
- dev_err(&pdev->dev, "Could not find platform data\n");
- return -EINVAL;
- }
-
/* Allocate memory for device */
ts_dev = kzalloc(sizeof(struct titsc), GFP_KERNEL);
input_dev = input_allocate_device();
@@ -342,11 +389,16 @@ static int titsc_probe(struct platform_device *pdev)
ts_dev->mfd_tscadc = tscadc_dev;
ts_dev->input = input_dev;
ts_dev->irq = tscadc_dev->irq;
- ts_dev->wires = pdata->tsc_init->wires;
- ts_dev->x_plate_resistance = pdata->tsc_init->x_plate_resistance;
- ts_dev->steps_to_configure = pdata->tsc_init->steps_to_configure;
- memcpy(ts_dev->config_inp, pdata->tsc_init->wire_config,
- sizeof(pdata->tsc_init->wire_config));
+
+ if (tscadc_dev->dev->platform_data)
+ err = titsc_parse_pdata(tscadc_dev, ts_dev);
+ else
+ err = titsc_parse_dt(pdev, ts_dev);
+
+ if (err) {
+ dev_err(&pdev->dev, "Could not find valid DT data.\n");
+ goto err_free_mem;
+ }

err = request_irq(ts_dev->irq, titsc_irq,
0, pdev->dev.driver->name, ts_dev);
@@ -362,7 +414,7 @@ static int titsc_probe(struct platform_device *pdev)
goto err_free_irq;
}
titsc_step_config(ts_dev);
- titsc_writel(ts_dev, REG_FIFO0THR, ts_dev->steps_to_configure);
+ titsc_writel(ts_dev, REG_FIFO0THR, ts_dev->coordinate_readouts);

input_dev->name = "ti-tsc";
input_dev->dev.parent = &pdev->dev;
@@ -398,7 +450,7 @@ static int titsc_remove(struct platform_device *pdev)
free_irq(ts_dev->irq, ts_dev);

/* total steps followed by the enable mask */
- steps = 2 * ts_dev->steps_to_configure + 2;
+ steps = 2 * ts_dev->coordinate_readouts + 2;
steps = (1 << steps) - 1;
am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);

@@ -439,7 +491,7 @@ static int titsc_resume(struct device *dev)
}
titsc_step_config(ts_dev);
titsc_writel(ts_dev, REG_FIFO0THR,
- ts_dev->steps_to_configure);
+ ts_dev->coordinate_readouts);
return 0;
}

@@ -452,6 +504,12 @@ static const struct dev_pm_ops titsc_pm_ops = {
#define TITSC_PM_OPS NULL
#endif

+static const struct of_device_id ti_tsc_dt_ids[] = {
+ { .compatible = "ti,am3359-tsc", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
+
static struct platform_driver ti_tsc_driver = {
.probe = titsc_probe,
.remove = titsc_remove,
@@ -459,6 +517,7 @@ static struct platform_driver ti_tsc_driver = {
.name = "tsc",
.owner = THIS_MODULE,
.pm = TITSC_PM_OPS,
+ .of_match_table = of_match_ptr(ti_tsc_dt_ids),
},
};
module_platform_driver(ti_tsc_driver);
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 90ccfc0..f509766 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -203,6 +203,7 @@ static int ti_tscadc_probe(struct platform_device *pdev)
/* TSC Cell */
cell = &tscadc->cells[TSC_CELL];
cell->name = "tsc";
+ cell->of_compatible = "ti,am3359-tsc";
cell->platform_data = &tscadc;
cell->pdata_size = sizeof(tscadc);

--
1.7.10.4

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