[PATCHv6][ 1/4] Input: tsc2007: Add device tree support.
Grant Likely
grant.likely at secretlab.ca
Thu Oct 24 06:16:24 EDT 2013
On Thu, 24 Oct 2013 10:38:50 +0200, Denis Carikli <denis at eukrea.com> wrote:
> Cc: Rob Herring <rob.herring at calxeda.com>
> Cc: Pawel Moll <pawel.moll at arm.com>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Stephen Warren <swarren at wwwdotorg.org>
> Cc: Ian Campbell <ijc+devicetree at hellion.org.uk>
> Cc: devicetree at vger.kernel.org
> Cc: Dmitry Torokhov <dmitry.torokhov at gmail.com>
> Cc: linux-input at vger.kernel.org
> Cc: Sascha Hauer <kernel at pengutronix.de>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: Lothar Waßmann <LW at KARO-electronics.de>
> Cc: Eric Bénard <eric at eukrea.com>
> Signed-off-by: Denis Carikli <denis at eukrea.com>
> ---
> ChangeLog v5->v6:
> - Fixed a code style issue.
> - Improved the documentation to set some gpio related properties as optional.
> - The properties related to the gpios are also explained better.
> ---
> .../bindings/input/touchscreen/tsc2007.txt | 44 +++++
> drivers/input/touchscreen/tsc2007.c | 194 +++++++++++++++-----
> 2 files changed, 197 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..46fc677
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> @@ -0,0 +1,44 @@
> +* 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]).
> +- max-rt: maximum pressure.
> +- fuzzy: specifies the fuzz value that is used to filter noise from the event
> + stream.
I don't actually understand what this means, can you clarify in the
document?
> +- poll-period: how much time to wait(in millisecond) before reading again the
> + values from the tsc2007.
max-rt, fuzzy, and poll-period should probably be prefixed with "ti,".
Otherwise the binding looks good to me.
g.
> +
> +[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 at 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..6b1d7a9 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, "max-rt", &val32))
> + ts->max_rt = val32;
> + else
> + ts->max_rt = MAX_12BIT;
> +
> + if (!of_property_read_u32(np, "fuzzy", &val32))
> + ts->fuzzy = val32;
> +
> + if (!of_property_read_u64(np, "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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