Input: cyttsp - switch to using device properties

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 <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

Documentation/devicetree/bindings/input/touchscreen/cyttsp.txt

···
+* 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]).
+ - 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:
+ - 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)
+ - 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>;
+		};
+
+		/* ... */
+	};

drivers/input/touchscreen/cyttsp_core.c

···
 #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"
 
···
 #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
···
 
 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);
 
···
 	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);
···
 {
 	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 */
···
 
 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,
···
 		cyttsp_disable(ts);
 }
 
-static void cyttsp_platform_exit(void *data)
+static int cyttsp_parse_properties(struct cyttsp *ts)
 {
-	struct cyttsp *ts = data;
+	struct device *dev = ts->dev;
+	u32 dt_value;
+	int ret;
 
-	if (ts->pdata->exit)
-		ts->pdata->exit();
+	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)
-		return ERR_PTR(-EINVAL);
 
 	ts = devm_kzalloc(dev, sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
 	if (!ts)
···
 
 	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_optional(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));
 
-	error = devm_add_action(dev, cyttsp_platform_exit, ts);
-	if (error) {
-		dev_err(dev, "failed to install exit action: %d\n", error);
-		return ERR_PTR(error);
-	}
-
-	if (pdata->init) {
-		error = pdata->init();
-		if (error) {
-			dev_err(ts->dev, "platform init failed, err: %d\n",
-				error);
-			return ERR_PTR(error);
-		}
-	}
-
-	input_dev->name = pdata->name;
+	input_dev->name = "Cypress TTSP TouchScreen";
 	input_dev->phys = ts->phys;
 	input_dev->id.bustype = bus_ops->bustype;
 	input_dev->dev.parent = ts->dev;
···
 
 	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);
 
 	error = input_mt_init_slots(input_dev, CY_MAX_ID, 0);
 	if (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);

drivers/input/touchscreen/cyttsp_core.h

···
 	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;
···
 	struct completion bl_ready;
 	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;
 };

include/linux/input/cyttsp.h

···
 /* 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_ */