Re: [PATCH v4 3/4] Input: cyttsp - switch to using device properties

Oreste Salerno
2016-01-21T19:26:00Z

On Thu, Jan 21, 2016 at 08:21:15PM +0100, Oreste Salerno wrote:
> Drop support for platform data passed via a C-structure and switch to
> device properties instead, which should make the driver compatible
> with all platforms: OF, ACPI and static boards. Static boards should
> use property sets to communicate device parameters to the driver.
>
> Signed-off-by: Oreste Salerno <oreste.salerno@tomtom.com>
> ---
> .../bindings/input/touchscreen/cyttsp.txt | 95 ++++++++++++
> drivers/input/touchscreen/cyttsp_core.c | 167 ++++++++++++++-------
> drivers/input/touchscreen/cyttsp_core.h | 10 +-
> drivers/input/touchscreen/cyttsp_i2c.c | 10 --
> drivers/input/touchscreen/cyttsp_spi.c | 10 --
> include/linux/input/cyttsp.h | 15 --
> 6 files changed, 213 insertions(+), 94 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt b/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt
> new file mode 100644
> index 0000000..b0fccae
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt
> @@ -0,0 +1,95 @@
> +* Cypress cyttsp touchscreen controller
> +
> +Required properties:
> + - compatible : must be "cypress,cyttsp-i2c" or "cypress,cyttsp-spi"
> + - reg : Device I2C address or SPI chip select number
> + - spi-max-frequency : Maximum SPI clocking speed of the device (for cyttsp-spi)
> + - interrupt-parent : the phandle for the gpio controller
> + (see interrupt binding[0]).
> + - interrupts : (gpio) interrupt to which the chip is connected
> + (see interrupt binding[0]).
> + - reset-gpios : the reset gpio the chip is connected to
> + (see GPIO binding[1] for more details).
> + - touchscreen-size-x : horizontal resolution of touchscreen (in pixels)
> + - touchscreen-size-y : vertical resolution of touchscreen (in pixels)

I decided to explicitly specify the generic touchscreen properties here (instead of
referring to touchscreen.txt) because not all properties listed in touchscreen.txt
are actually parsed by the driver.

> + - bootloader-key : the 8-byte bootloader key that is required to switch
> + the chip from bootloader mode (default mode) to
> + application mode.
> + This property has to be specified as an array of 8
> + '/bits/ 8' values.
> +
> +Optional properties:
> + - touchscreen-fuzz-x : horizontal noise value of the absolute input device
> + (in pixels)
> + - touchscreen-fuzz-y : vertical noise value of the absolute input device
> + (in pixels)
> + - active-distance : the distance in pixels beyond which a touch must move
> + before movement is detected and reported by the device.
> + Valid values: 0-15.
> + - active-interval-ms : the minimum period in ms between consecutive
> + scanning/processing cycles when the chip is in active mode.
> + Valid values: 0-255.
> + - lowpower-interval-ms : the minimum period in ms between consecutive
> + scanning/processing cycles when the chip is in low-power mode.
> + Valid values: 0-2550
> + - touch-timeout-ms : minimum time in ms spent in the active power state while no
> + touches are detected before entering low-power mode.
> + Valid values: 0-2550
> + - use-handshake : enable register-based handshake (boolean). This should
> + only be used if the chip is configured to use 'blocking
> + communication with timeout' (in this case the device
> + generates an interrupt at the end of every
> + scanning/processing cycle).
> +
> +[0]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> +[1]: Documentation/devicetree/bindings/gpio/gpio.txt
> +
> +Example:
> + &i2c1 {
> + /* ... */
> + cyttsp@a {
> + compatible = "cypress,cyttsp-i2c";
> + reg = <0xa>;
> + interrupt-parent = <&gpio0>;
> + interrupts = <28 0>;
> + reset-gpios = <&gpio3 4 GPIO_ACTIVE_LOW>;
> +
> + touchscreen-size-x = <800>;
> + touchscreen-size-y = <480>;
> + touchscreen-fuzz-x = <4>;
> + touchscreen-fuzz-y = <7>;
> +
> + bootloader-key = /bits/ 8 <0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08>;
> + active-distance = <8>;
> + active-interval-ms = <0>;
> + lowpower-interval-ms = <200>;
> + touch-timeout-ms = <100>;
> + };
> +
> + /* ... */
> + };
> +
> + &mcspi1 {
> + /* ... */
> + cyttsp@0 {
> + compatible = "cypress,cyttsp-spi";
> + spi-max-frequency = <6000000>;
> + reg = <0>;
> + interrupt-parent = <&gpio0>;
> + interrupts = <28 0>;
> + reset-gpios = <&gpio3 4 GPIO_ACTIVE_LOW>;
> +
> + touchscreen-size-x = <800>;
> + touchscreen-size-y = <480>;
> + touchscreen-fuzz-x = <4>;
> + touchscreen-fuzz-y = <7>;
> +
> + bootloader-key = /bits/ 8 <0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08>;
> + active-distance = <8>;
> + active-interval-ms = <0>;
> + lowpower-interval-ms = <200>;
> + touch-timeout-ms = <100>;
> + };
> +
> + /* ... */
> + };
> diff --git a/drivers/input/touchscreen/cyttsp_core.c b/drivers/input/touchscreen/cyttsp_core.c
> index 10379bc..92b459d 100644
> --- a/drivers/input/touchscreen/cyttsp_core.c
> +++ b/drivers/input/touchscreen/cyttsp_core.c
> @@ -30,9 +30,12 @@
> #include <linux/delay.h>
> #include <linux/input.h>
> #include <linux/input/mt.h>
> +#include <linux/input/touchscreen.h>
> #include <linux/gpio.h>
> #include <linux/interrupt.h>
> #include <linux/slab.h>
> +#include <linux/property.h>
> +#include <linux/gpio/consumer.h>
>
> #include "cyttsp_core.h"
>
> @@ -57,6 +60,7 @@
> #define CY_DELAY_DFLT 20 /* ms */
> #define CY_DELAY_MAX 500
> #define CY_ACT_DIST_DFLT 0xF8
> +#define CY_ACT_DIST_MASK 0x0F
> #define CY_HNDSHK_BIT 0x80
> /* device mode bits */
> #define CY_OPERATE_MODE 0x00
> @@ -120,7 +124,7 @@ static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
>
> static int cyttsp_handshake(struct cyttsp *ts)
> {
> - if (ts->pdata->use_hndshk)
> + if (ts->use_hndshk)
> return ttsp_send_command(ts,
> ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
>
> @@ -142,9 +146,9 @@ static int cyttsp_exit_bl_mode(struct cyttsp *ts)
> u8 bl_cmd[sizeof(bl_command)];
>
> memcpy(bl_cmd, bl_command, sizeof(bl_command));
> - if (ts->pdata->bl_keys)
> + if (ts->bl_keys)
> memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
> - ts->pdata->bl_keys, CY_NUM_BL_KEYS);
> + ts->bl_keys, CY_NUM_BL_KEYS);
>
> error = ttsp_write_block_data(ts, CY_REG_BASE,
> sizeof(bl_cmd), bl_cmd);
> @@ -217,14 +221,14 @@ static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
> {
> int retval = 0;
>
> - if (ts->pdata->act_intrvl != CY_ACT_INTRVL_DFLT ||
> - ts->pdata->tch_tmout != CY_TCH_TMOUT_DFLT ||
> - ts->pdata->lp_intrvl != CY_LP_INTRVL_DFLT) {
> + if (ts->act_intrvl != CY_ACT_INTRVL_DFLT ||
> + ts->tch_tmout != CY_TCH_TMOUT_DFLT ||
> + ts->lp_intrvl != CY_LP_INTRVL_DFLT) {
>
> u8 intrvl_ray[] = {
> - ts->pdata->act_intrvl,
> - ts->pdata->tch_tmout,
> - ts->pdata->lp_intrvl
> + ts->act_intrvl,
> + ts->tch_tmout,
> + ts->lp_intrvl
> };
>
> /* set intrvl registers */
> @@ -263,7 +267,7 @@ out:
>
> static int cyttsp_act_dist_setup(struct cyttsp *ts)
> {
> - u8 act_dist_setup = ts->pdata->act_dist;
> + u8 act_dist_setup = ts->act_dist;
>
> /* Init gesture; active distance setup */
> return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
> @@ -528,45 +532,107 @@ static void cyttsp_close(struct input_dev *dev)
> cyttsp_disable(ts);
> }
>
> +static int cyttsp_parse_properties(struct cyttsp *ts)
> +{
> + struct device *dev = ts->dev;
> + u32 dt_value;
> + int ret;
> +
> + ts->bl_keys = devm_kzalloc(dev, CY_NUM_BL_KEYS, GFP_KERNEL);
> + if (!ts->bl_keys)
> + return -ENOMEM;
> +
> + /* Set some default values */
> + ts->use_hndshk = false;
> + ts->act_dist = CY_ACT_DIST_DFLT;
> + ts->act_intrvl = CY_ACT_INTRVL_DFLT;
> + ts->tch_tmout = CY_TCH_TMOUT_DFLT;
> + ts->lp_intrvl = CY_LP_INTRVL_DFLT;
> +
> + ret = device_property_read_u8_array(dev, "bootloader-key",
> + ts->bl_keys, CY_NUM_BL_KEYS);
> + if (ret) {
> + dev_err(dev,
> + "bootloader-key property could not be retrieved\n");
> + return ret;
> + }
> +
> + ts->use_hndshk = device_property_present(dev, "use-handshake");
> +
> + if (!device_property_read_u32(dev, "active-distance", &dt_value)) {
> + if (dt_value > 15) {
> + dev_err(dev, "active-distance (%u) must be [0-15]\n",
> + dt_value);
> + return -EINVAL;
> + }
> + ts->act_dist &= ~CY_ACT_DIST_MASK;
> + ts->act_dist |= dt_value;
> + }
> +
> + if (!device_property_read_u32(dev, "active-interval-ms", &dt_value)) {
> + if (dt_value > 255) {
> + dev_err(dev, "active-interval-ms (%u) must be [0-255]\n",
> + dt_value);
> + return -EINVAL;
> + }
> + ts->act_intrvl = dt_value;
> + }
> +
> + if (!device_property_read_u32(dev, "lowpower-interval-ms", &dt_value)) {
> + if (dt_value > 2550) {
> + dev_err(dev, "lowpower-interval-ms (%u) must be [0-2550]\n",
> + dt_value);
> + return -EINVAL;
> + }
> + /* Register value is expressed in 0.01s / bit */
> + ts->lp_intrvl = dt_value / 10;
> + }
> +
> + if (!device_property_read_u32(dev, "touch-timeout-ms", &dt_value)) {
> + if (dt_value > 2550) {
> + dev_err(dev, "touch-timeout-ms (%u) must be [0-2550]\n",
> + dt_value);
> + return -EINVAL;
> + }
> + /* Register value is expressed in 0.01s / bit */
> + ts->tch_tmout = dt_value/10;
> + }
> +
> + return 0;
> +}
> +
> struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
> struct device *dev, int irq, size_t xfer_buf_size)
> {
> - const struct cyttsp_platform_data *pdata = dev_get_platdata(dev);
> struct cyttsp *ts;
> struct input_dev *input_dev;
> int error;
>
> - if (!pdata || !pdata->name || irq <= 0) {
> - error = -EINVAL;
> - goto err_out;
> - }
> -
> ts = devm_kzalloc(dev, sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
> input_dev = devm_input_allocate_device(dev);
> - if (!ts || !input_dev) {
> - error = -ENOMEM;
> - goto err_out;
> - }
> + if (!ts || !input_dev)
> + return ERR_PTR(-ENOMEM);
>
> ts->dev = dev;
> ts->input = input_dev;
> - ts->pdata = dev_get_platdata(dev);
> ts->bus_ops = bus_ops;
> ts->irq = irq;
>
> + ts->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> + if (IS_ERR(ts->reset_gpio)) {
> + error = PTR_ERR(ts->reset_gpio);
> + dev_err(dev, "Failed to request reset gpio, error %d\n", error);
> + return ERR_PTR(error);
> + }
> +
> + error = cyttsp_parse_properties(ts);
> + if (error)
> + return ERR_PTR(error);
> +
> init_completion(&ts->bl_ready);
> snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
>
> - if (pdata->init) {
> - error = pdata->init();
> - if (error) {
> - dev_err(ts->dev, "platform init failed, err: %d\n",
> - error);
> - goto err_out;
> - }
> - }
> -
> - input_dev->name = pdata->name;
> + input_dev->name = "cyttsp";
> input_dev->phys = ts->phys;
> input_dev->id.bustype = bus_ops->bustype;
> input_dev->dev.parent = ts->dev;
> @@ -576,59 +642,46 @@ struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
>
> input_set_drvdata(input_dev, ts);
>
> - __set_bit(EV_ABS, input_dev->evbit);
> - input_set_abs_params(input_dev, ABS_MT_POSITION_X,
> - 0, pdata->maxx, 0, 0);
> - input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
> - 0, pdata->maxy, 0, 0);
> - input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
> - 0, CY_MAXZ, 0, 0);
> + input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
> + input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
> + touchscreen_parse_properties(input_dev, true);
> + if (!input_abs_get_max(input_dev, ABS_MT_POSITION_X) ||
> + !input_abs_get_max(input_dev, ABS_MT_POSITION_Y)) {
> + dev_err(dev, "Touchscreen size is not specified\n");
> + return ERR_PTR(-EINVAL);
> + }
>
> error = input_mt_init_slots(input_dev, CY_MAX_ID, 0);
> if (error) {
> dev_err(dev, "Unable to init MT slots.\n");
> - goto err_platform_exit;
> + return ERR_PTR(error);
> }
>
> error = devm_request_threaded_irq(dev, ts->irq, NULL, cyttsp_irq,
> IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> - pdata->name, ts);
> + "cyttsp", ts);
> if (error) {
> dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
> ts->irq, error);
> - goto err_platform_exit;
> + return ERR_PTR(error);
> }
>
> disable_irq(ts->irq);
>
> error = cyttsp_power_on(ts);
> if (error)
> - goto err_platform_exit;
> + return ERR_PTR(error);
>
> error = input_register_device(input_dev);
> if (error) {
> dev_err(ts->dev, "failed to register input device: %d\n",
> error);
> - goto err_platform_exit;
> + return ERR_PTR(error);
> }
> -
> return ts;
> -
> -err_platform_exit:
> - if (pdata->exit)
> - pdata->exit();
> -err_out:
> - return ERR_PTR(error);
> }
> EXPORT_SYMBOL_GPL(cyttsp_probe);
>
> -void cyttsp_remove(struct cyttsp *ts)
> -{
> - if (ts->pdata->exit)
> - ts->pdata->exit();
> -}
> -EXPORT_SYMBOL_GPL(cyttsp_remove);
> -
> MODULE_LICENSE("GPL");
> MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
> MODULE_AUTHOR("Cypress");
> diff --git a/drivers/input/touchscreen/cyttsp_core.h b/drivers/input/touchscreen/cyttsp_core.h
> index 0707411..7835e2b 100644
> --- a/drivers/input/touchscreen/cyttsp_core.h
> +++ b/drivers/input/touchscreen/cyttsp_core.h
> @@ -129,7 +129,6 @@ struct cyttsp {
> int irq;
> struct input_dev *input;
> char phys[32];
> - const struct cyttsp_platform_data *pdata;
> const struct cyttsp_bus_ops *bus_ops;
> struct cyttsp_bootloader_data bl_data;
> struct cyttsp_sysinfo_data sysinfo_data;
> @@ -138,12 +137,19 @@ struct cyttsp {
> enum cyttsp_state state;
> bool suspended;
>
> + struct gpio_desc *reset_gpio;
> + bool use_hndshk;
> + u8 act_dist;
> + u8 act_intrvl;
> + u8 tch_tmout;
> + u8 lp_intrvl;
> + u8 *bl_keys;
> +
> u8 xfer_buf[] ____cacheline_aligned;
> };
>
> struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
> struct device *dev, int irq, size_t xfer_buf_size);
> -void cyttsp_remove(struct cyttsp *ts);
>
> int cyttsp_i2c_write_block_data(struct device *dev, u8 *xfer_buf, u16 addr,
> u8 length, const void *values);
> diff --git a/drivers/input/touchscreen/cyttsp_i2c.c b/drivers/input/touchscreen/cyttsp_i2c.c
> index eee51b3..1edfdba 100644
> --- a/drivers/input/touchscreen/cyttsp_i2c.c
> +++ b/drivers/input/touchscreen/cyttsp_i2c.c
> @@ -56,15 +56,6 @@ static int cyttsp_i2c_probe(struct i2c_client *client,
> return 0;
> }
>
> -static int cyttsp_i2c_remove(struct i2c_client *client)
> -{
> - struct cyttsp *ts = i2c_get_clientdata(client);
> -
> - cyttsp_remove(ts);
> -
> - return 0;
> -}
> -
> static const struct i2c_device_id cyttsp_i2c_id[] = {
> { CY_I2C_NAME, 0 },
> { }
> @@ -77,7 +68,6 @@ static struct i2c_driver cyttsp_i2c_driver = {
> .pm = &cyttsp_pm_ops,
> },
> .probe = cyttsp_i2c_probe,
> - .remove = cyttsp_i2c_remove,
> .id_table = cyttsp_i2c_id,
> };
>
> diff --git a/drivers/input/touchscreen/cyttsp_spi.c b/drivers/input/touchscreen/cyttsp_spi.c
> index bbeeb24..3c9d18b 100644
> --- a/drivers/input/touchscreen/cyttsp_spi.c
> +++ b/drivers/input/touchscreen/cyttsp_spi.c
> @@ -170,22 +170,12 @@ static int cyttsp_spi_probe(struct spi_device *spi)
> return 0;
> }
>
> -static int cyttsp_spi_remove(struct spi_device *spi)
> -{
> - struct cyttsp *ts = spi_get_drvdata(spi);
> -
> - cyttsp_remove(ts);
> -
> - return 0;
> -}
> -
> static struct spi_driver cyttsp_spi_driver = {
> .driver = {
> .name = CY_SPI_NAME,
> .pm = &cyttsp_pm_ops,
> },
> .probe = cyttsp_spi_probe,
> - .remove = cyttsp_spi_remove,
> };
>
> module_spi_driver(cyttsp_spi_driver);
> diff --git a/include/linux/input/cyttsp.h b/include/linux/input/cyttsp.h
> index 5af7c66..586c8c9 100644
> --- a/include/linux/input/cyttsp.h
> +++ b/include/linux/input/cyttsp.h
> @@ -40,19 +40,4 @@
> /* Active distance in pixels for a gesture to be reported */
> #define CY_ACT_DIST_DFLT 0xF8 /* pixels */
>
> -struct cyttsp_platform_data {
> - u32 maxx;
> - u32 maxy;
> - bool use_hndshk;
> - u8 act_dist; /* Active distance */
> - u8 act_intrvl; /* Active refresh interval; ms */
> - u8 tch_tmout; /* Active touch timeout; ms */
> - u8 lp_intrvl; /* Low power refresh interval; ms */
> - int (*init)(void);
> - void (*exit)(void);
> - char *name;
> - s16 irq_gpio;
> - u8 *bl_keys;
> -};
> -
> #endif /* _CYTTSP_H_ */
> --
> 1.9.1
>