[PATCHv7][ 1/4] Input: tsc2007: Add device tree support.

Denis Carikli
2013-10-24T12:42:13Z

Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: devicetree@vger.kernel.org
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: linux-input@vger.kernel.org
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: Eric Bénard <eric@eukrea.com>
Signed-off-by: Denis Carikli <denis@eukrea.com>
---
ChangeLog v6->v7:
- One small whitespace cleanup.
- The properties specific to that driver are now prefixed with "ti,".
- The ti,fuzzy property has now better documentation.
---
.../bindings/input/touchscreen/tsc2007.txt | 45 +++++
drivers/input/touchscreen/tsc2007.c | 194 +++++++++++++++-----
2 files changed, 198 insertions(+), 41 deletions(-)
create mode 100644 Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt

diff --git a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
new file mode 100644
index 0000000..516b63b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
@@ -0,0 +1,45 @@
+* Texas Instruments tsc2007 touchscreen controller
+
+Required properties:
+- compatible: must be "ti,tsc2007".
+- reg: I2C address of the chip.
+- ti,x-plate-ohms: X-plate resistance in ohms.
+
+Optional properties:
+- gpios: the interrupt gpio the chip is connected to (trough the penirq pin)
+ (see GPIO binding[2] for more details).
+- interrupt-parent: the phandle for the gpio controller
+ (see interrupt binding[1]).
+- interrupts: (gpio) interrupt to which the chip is connected
+ (see interrupt binding[1]).
+- pinctrl-0: Should specify pin control groups used for the gpio
+ (see pinctrl bindings[0]).
+- pinctrl-names: Should contain only one value - "default"
+ (see pinctrl bindings[0]).
+- ti,max-rt: maximum pressure.
+- ti,fuzzy: specifies the absolute input fuzz value.
+ If set, it will permit noise in the data up to +- the value given to the fuzz
+ parameter, that is used to filter noise from the event stream.
+- ti,poll-period: how much time to wait(in millisecond) before reading again the
+ values from the tsc2007.
+
+[0]: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+[1]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+[2]: Documentation/devicetree/bindings/gpio/gpio.txt
+
+Example:
+ &i2c1 {
+ /* ... */
+ tsc2007@49 {
+ compatible = "ti,tsc2007";
+ reg = <0x49>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_tsc2007_1>;
+ interrupt-parent = <&gpio4>;
+ interrupts = <0x0 0x8>;
+ gpios = <&gpio4 0 0>;
+ ti,x-plate-ohms = <180>;
+ };
+
+ /* ... */
+ };
diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index 0b67ba4..c50d64e 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -26,6 +26,9 @@
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/i2c/tsc2007.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>

#define TSC2007_MEASURE_TEMP0 (0x0 << 4)
#define TSC2007_MEASURE_AUX (0x2 << 4)
@@ -74,7 +77,10 @@ struct tsc2007 {
u16 max_rt;
unsigned long poll_delay;
unsigned long poll_period;
+ int fuzzy;
+ char of;

+ unsigned gpio;
int irq;

wait_queue_head_t wait;
@@ -84,6 +90,11 @@ struct tsc2007 {
void (*clear_penirq)(void);
};

+static int tsc2007_get_pendown_state_dt(struct tsc2007 *ts)
+{
+ return !gpio_get_value(ts->gpio);
+}
+
static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
{
s32 data;
@@ -142,6 +153,14 @@ static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
return rt;
}

+static bool tsc2007_is_pen_down_valid(struct tsc2007 *ts)
+{
+ if (ts->of)
+ return gpio_is_valid(ts->gpio);
+ else
+ return ts->get_pendown_state ? true : false;
+}
+
static bool tsc2007_is_pen_down(struct tsc2007 *ts)
{
/*
@@ -158,10 +177,13 @@ static bool tsc2007_is_pen_down(struct tsc2007 *ts)
* to fall back on the pressure reading.
*/

- if (!ts->get_pendown_state)
+ if (!tsc2007_is_pen_down_valid(ts))
return true;

- return ts->get_pendown_state();
+ if (ts->of)
+ return tsc2007_get_pendown_state_dt(ts);
+ else
+ return ts->get_pendown_state();
}

static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
@@ -178,7 +200,7 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)

rt = tsc2007_calculate_pressure(ts, &tc);

- if (rt == 0 && !ts->get_pendown_state) {
+ if (!rt && !tsc2007_is_pen_down_valid(ts)) {
/*
* If pressure reported is 0 and we don't have
* callback to check pendown state, we have to
@@ -228,7 +250,7 @@ static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
{
struct tsc2007 *ts = handle;

- if (!ts->get_pendown_state || likely(ts->get_pendown_state()))
+ if (tsc2007_is_pen_down(ts))
return IRQ_WAKE_THREAD;

if (ts->clear_penirq)
@@ -273,34 +295,65 @@ static void tsc2007_close(struct input_dev *input_dev)
tsc2007_stop(ts);
}

-static int tsc2007_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+#ifdef CONFIG_OF
+static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts,
+ struct device_node *np)
{
- struct tsc2007 *ts;
- struct tsc2007_platform_data *pdata = client->dev.platform_data;
- struct input_dev *input_dev;
- int err;
-
- if (!pdata) {
- dev_err(&client->dev, "platform data is required!\n");
+ int err = 0;
+ u32 val32;
+ u64 val64;
+
+ if (!of_property_read_u32(np, "ti,max-rt", &val32))
+ ts->max_rt = val32;
+ else
+ ts->max_rt = MAX_12BIT;
+
+ if (!of_property_read_u32(np, "ti,fuzzy", &val32))
+ ts->fuzzy = val32;
+
+ if (!of_property_read_u64(np, "ti,poll-period", &val64))
+ ts->poll_period = val64;
+ else
+ ts->poll_period = 1;
+
+ if (!of_property_read_u32(np, "ti,x-plate-ohms", &val32)) {
+ ts->x_plate_ohms = val32;
+ } else {
+ dev_err(&client->dev,
+ "Error: lacking ti,x-plate-ohms devicetree property. (err %d).",
+ err);
return -EINVAL;
}

- if (!i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_READ_WORD_DATA))
- return -EIO;
+ ts->gpio = of_get_gpio(np, 0);
+ if (!gpio_is_valid(ts->gpio))
+ dev_err(&client->dev,
+ "GPIO not found (of_get_gpio returned %d)\n",
+ ts->gpio);

- ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
- input_dev = input_allocate_device();
- if (!ts || !input_dev) {
- err = -ENOMEM;
- goto err_free_mem;
- }
+ /* Used to detect if it is probed trough the device tree,
+ * in order to be able to use that information in the IRQ handler.
+ */
+ ts->of = 1;

- ts->client = client;
- ts->irq = client->irq;
- ts->input = input_dev;
- init_waitqueue_head(&ts->wait);
+ return 0;
+}
+#else
+static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts,
+ struct device_node *np)
+{
+ return -ENODEV;
+}
+#endif
+
+static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts,
+ struct tsc2007_platform_data *pdata,
+ const struct i2c_device_id *id)
+{
+ if (!pdata) {
+ dev_err(&client->dev, "platform data is required!\n");
+ return -EINVAL;
+ }

ts->model = pdata->model;
ts->x_plate_ohms = pdata->x_plate_ohms;
@@ -309,13 +362,57 @@ static int tsc2007_probe(struct i2c_client *client,
ts->poll_period = pdata->poll_period ? : 1;
ts->get_pendown_state = pdata->get_pendown_state;
ts->clear_penirq = pdata->clear_penirq;
+ ts->fuzzy = pdata->fuzzy;

if (pdata->x_plate_ohms == 0) {
dev_err(&client->dev, "x_plate_ohms is not set up in platform data");
- err = -EINVAL;
- goto err_free_mem;
+ return -EINVAL;
}

+ /* Used to detect if it is probed trough the device tree,
+ * in order to be able to use that information in the IRQ handler.
+ */
+ ts->of = 0;
+
+ return 0;
+}
+
+static int tsc2007_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device_node *np = client->dev.of_node;
+ struct tsc2007_platform_data *pdata = client->dev.platform_data;
+ struct tsc2007 *ts;
+ struct input_dev *input_dev;
+ int err = 0;
+
+ ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ if (np)
+ err = tsc2007_probe_dt(client, ts, np);
+ else
+ err = tsc2007_probe_pdev(client, ts, pdata, id);
+
+ if (err)
+ return err;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_WORD_DATA))
+ return -EIO;
+
+ input_dev = input_allocate_device();
+ if (!input_dev) {
+ err = -ENOMEM;
+ goto err_free_input;
+ };
+
+ ts->client = client;
+ ts->irq = client->irq;
+ ts->input = input_dev;
+ init_waitqueue_head(&ts->wait);
+
snprintf(ts->phys, sizeof(ts->phys),
"%s/input0", dev_name(&client->dev));

@@ -331,19 +428,21 @@ static int tsc2007_probe(struct i2c_client *client,
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

- input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, pdata->fuzzx, 0);
- input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, pdata->fuzzy, 0);
+ input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzy, 0);
+ input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0);
input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
- pdata->fuzzz, 0);
+ ts->fuzzy, 0);

- if (pdata->init_platform_hw)
- pdata->init_platform_hw();
+ if (!np) {
+ if (pdata->init_platform_hw)
+ pdata->init_platform_hw();
+ }

err = request_threaded_irq(ts->irq, tsc2007_hard_irq, tsc2007_soft_irq,
IRQF_ONESHOT, client->dev.driver->name, ts);
if (err < 0) {
dev_err(&client->dev, "irq %d busy?\n", ts->irq);
- goto err_free_mem;
+ goto err_free_input;
}

tsc2007_stop(ts);
@@ -358,23 +457,27 @@ static int tsc2007_probe(struct i2c_client *client,

err_free_irq:
free_irq(ts->irq, ts);
- if (pdata->exit_platform_hw)
- pdata->exit_platform_hw();
- err_free_mem:
+ if (!np) {
+ if (pdata->exit_platform_hw)
+ pdata->exit_platform_hw();
+ }
+ err_free_input:
input_free_device(input_dev);
- kfree(ts);
return err;
}

static int tsc2007_remove(struct i2c_client *client)
{
+ struct device_node *np = client->dev.of_node;
struct tsc2007 *ts = i2c_get_clientdata(client);
struct tsc2007_platform_data *pdata = client->dev.platform_data;

free_irq(ts->irq, ts);

- if (pdata->exit_platform_hw)
- pdata->exit_platform_hw();
+ if (!np) {
+ if (pdata->exit_platform_hw)
+ pdata->exit_platform_hw();
+ }

input_unregister_device(ts->input);
kfree(ts);
@@ -389,10 +492,19 @@ static const struct i2c_device_id tsc2007_idtable[] = {

MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);

+#ifdef CONFIG_OF
+static const struct of_device_id tsc2007_of_match[] = {
+ { .compatible = "ti,tsc2007" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, tsc2007_of_match);
+#endif
+
static struct i2c_driver tsc2007_driver = {
.driver = {
.owner = THIS_MODULE,
- .name = "tsc2007"
+ .name = "tsc2007",
+ .of_match_table = of_match_ptr(tsc2007_of_match),
},
.id_table = tsc2007_idtable,
.probe = tsc2007_probe,
--
1.7.9.5

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