[PATCH 6/7] Input: sx8654 - add sx8650 support

Richard Leitner
2018-10-16T09:24:00Z

The sx8654 and sx8650 are quite similar, therefore add support for the
sx8650 within the sx8654 driver.

Signed-off-by: Richard Leitner <richard.leitner@skidata.com>
---
drivers/input/touchscreen/sx8654.c | 186 ++++++++++++++++++++++++++++++++-----
1 file changed, 163 insertions(+), 23 deletions(-)

diff --git a/drivers/input/touchscreen/sx8654.c b/drivers/input/touchscreen/sx8654.c
index 622283b49d7c..33f7a0be4ef8 100644
--- a/drivers/input/touchscreen/sx8654.c
+++ b/drivers/input/touchscreen/sx8654.c
@@ -29,12 +29,13 @@

#include <linux/input.h>
#include <linux/module.h>
-#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/gpio/consumer.h>
#include <linux/delay.h>
+#include <linux/hrtimer.h>

/* register addresses */
#define I2C_REG_TOUCH0 0x00
@@ -44,9 +45,11 @@
#define I2C_REG_IRQSRC 0x23
#define I2C_REG_SOFTRESET 0x3f

+#define I2C_REG_SX8650_STAT 0x05
+#define SX8650_STAT_CONVIRQ BIT(7)
+
/* commands */
#define CMD_READ_REGISTER 0x40
-#define CMD_MANUAL 0xc0
#define CMD_PENTRG 0xe0

/* value for I2C_REG_SOFTRESET */
@@ -58,11 +61,12 @@

/* bits for RegTouch1 */
#define CONDIRQ 0x20
+#define RPDNT_100K 0x00
#define FILT_7SA 0x03

/* bits for I2C_REG_CHANMASK */
-#define CONV_X 0x80
-#define CONV_Y 0x40
+#define CONV_X BIT(7)
+#define CONV_Y BIT(6)

/* coordinates rate: higher nibble of CTRL0 register */
#define RATE_MANUAL 0x00
@@ -71,14 +75,110 @@
/* power delay: lower nibble of CTRL0 register */
#define POWDLY_1_1MS 0x0b

+/* for sx8650, as we have no pen release IRQ there: timeout in ns following the
+ * last PENIRQ after which we assume the pen is lifted.
+ */
+#define SX8650_PENIRQ_TIMEOUT (80 * 1100 * 1000)
+
#define MAX_12BIT ((1 << 12) - 1)
+#define MAX_I2C_READ_LEN 10 /* see datasheet section 5.1.5 */
+
+/* channel definition */
+#define CH_X 0x00
+#define CH_Y 0x01
+
+struct sx865x_data {
+ u8 cmd_manual;
+ u8 chan_mask;
+ u8 has_irq_penrelease;
+ u8 has_reg_irqmask;
+ irq_handler_t irqh;
+};

struct sx8654 {
struct input_dev *input;
struct i2c_client *client;
struct gpio_desc *gpio_reset;
+ struct hrtimer timer;
+
+ const struct sx865x_data *data;
};

+static enum hrtimer_restart sx865x_penrelease_timer_handler(struct hrtimer *h)
+{
+ struct sx8654 *ts = container_of(h, struct sx8654, timer);
+
+ input_report_key(ts->input, BTN_TOUCH, 0);
+ input_sync(ts->input);
+ dev_dbg(&ts->client->dev, "penrelease by timer\n");
+
+ return HRTIMER_NORESTART;
+}
+
+static irqreturn_t sx8650_irq(int irq, void *handle)
+{
+ struct sx8654 *ts = handle;
+ struct device *dev = &ts->client->dev;
+ int len, i, ret;
+ u8 stat;
+ u16 x, y;
+ u8 data[MAX_I2C_READ_LEN];
+ u16 ch;
+ u16 chdata;
+ u8 readlen = hweight32(ts->data->chan_mask) * 2;
+
+ stat = i2c_smbus_read_byte_data(ts->client, CMD_READ_REGISTER
+ | I2C_REG_SX8650_STAT);
+
+ if (!(stat & SX8650_STAT_CONVIRQ)) {
+ dev_dbg(dev, "%s ignore stat [0x%02x]", __func__, stat);
+ return IRQ_HANDLED;
+ }
+
+ len = i2c_master_recv(ts->client, data, readlen);
+ if (len != readlen) {
+ dev_dbg(dev, "ignore short recv (%d)\n", len);
+ return IRQ_HANDLED;
+ }
+
+ ret = hrtimer_try_to_cancel(&ts->timer);
+
+ x = 0;
+ y = 0;
+ for (i = 0; (i + 1) < len; i++) {
+ chdata = data[i] << 8;
+ i++;
+ chdata += data[i];
+
+ if (unlikely(chdata == 0xFFFF)) {
+ dev_dbg(dev, "invalid qualified data @ %d\n", i);
+ continue;
+ } else if (unlikely(chdata & 0x8000)) {
+ dev_warn(dev, "hibit @ %d [0x%04x]\n", i, chdata);
+ continue;
+ }
+
+ ch = chdata >> 12;
+ if (ch == CH_X)
+ x = chdata & MAX_12BIT;
+ else if (ch == CH_Y)
+ y = chdata & MAX_12BIT;
+ else
+ dev_warn(dev, "unknown channel %d [0x%04x]\n", ch,
+ chdata);
+ }
+
+ input_report_abs(ts->input, ABS_X, x);
+ input_report_abs(ts->input, ABS_Y, y);
+ input_report_key(ts->input, BTN_TOUCH, 1);
+ input_sync(ts->input);
+ dev_dbg(dev, "point(%4d,%4d)\n", x, y);
+
+ hrtimer_start(&ts->timer, ktime_set(0, SX8650_PENIRQ_TIMEOUT),
+ HRTIMER_MODE_REL);
+ return IRQ_HANDLED;
+}
+
static irqreturn_t sx8654_irq(int irq, void *handle)
{
struct sx8654 *sx8654 = handle;
@@ -127,6 +227,22 @@ static irqreturn_t sx8654_irq(int irq, void *handle)
return IRQ_HANDLED;
}

+static const struct sx865x_data sx8650_data = {
+ .cmd_manual = 0xb0,
+ .has_irq_penrelease = 0,
+ .has_reg_irqmask = 0,
+ .chan_mask = (CONV_X | CONV_Y),
+ .irqh = sx8650_irq,
+};
+
+static const struct sx865x_data sx8654_data = {
+ .cmd_manual = 0xc0,
+ .has_irq_penrelease = 1,
+ .has_reg_irqmask = 1,
+ .chan_mask = (CONV_X | CONV_Y),
+ .irqh = sx8654_irq,
+};
+
static int sx8654_reset(struct sx8654 *ts)
{
int err;
@@ -182,13 +298,13 @@ static void sx8654_close(struct input_dev *dev)
disable_irq(client->irq);

/* enable manual mode mode */
- error = i2c_smbus_write_byte(client, CMD_MANUAL);
+ error = i2c_smbus_write_byte(client, sx8654->data->cmd_manual);
if (error) {
dev_err(&client->dev, "writing command CMD_MANUAL failed");
return;
}

- error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0, 0);
+ error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0, RATE_MANUAL);
if (error) {
dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
return;
@@ -196,10 +312,30 @@ static void sx8654_close(struct input_dev *dev)
}

#ifdef CONFIG_OF
+static const struct of_device_id sx8654_of_match[] = {
+ {
+ .compatible = "semtech,sx8650",
+ .data = &sx8650_data,
+ }, {
+ .compatible = "semtech,sx8654",
+ .data = &sx8654_data,
+ }, {
+ .compatible = "semtech,sx8655",
+ .data = &sx8654_data,
+ }, {
+ .compatible = "semtech,sx8656",
+ .data = &sx8654_data,
+ }, {},
+};
+MODULE_DEVICE_TABLE(of, sx8654_of_match);
+
static int sx8654_get_ofdata(struct sx8654 *ts)
{
struct device *dev = &ts->client->dev;
struct device_node *node = dev->of_node;
+ const struct of_device_id *of_id = of_match_device(sx8654_of_match,
+ dev);
+ const struct sx865x_data *data = (struct sx865x_data *)of_id->data;
int err;

if (!node) {
@@ -207,6 +343,8 @@ static int sx8654_get_ofdata(struct sx8654 *ts)
return 0;
}

+ ts->data = data;
+
ts->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
if (PTR_ERR(ts->gpio_reset) == -EPROBE_DEFER) {
return -EPROBE_DEFER;
@@ -219,18 +357,11 @@ static int sx8654_get_ofdata(struct sx8654 *ts)

return 0;
}
-
-static const struct of_device_id sx8654_of_match[] = {
- { .compatible = "semtech,sx8654", },
- { .compatible = "semtech,sx8655", },
- { .compatible = "semtech,sx8656", },
- { },
-};
-MODULE_DEVICE_TABLE(of, sx8654_of_match);
#else /* CONFIG_OF */
static int sx8654_get_ofdata(struct sx8654 *ts)
{
ts->gpio_reset = NULL;
+ ts->data = &sx8654_data;
return 0;
}
#endif /* CONFIG_OF */
@@ -258,6 +389,12 @@ static int sx8654_probe(struct i2c_client *client,
return error;
}

+ if (!sx8654->data->has_irq_penrelease) {
+ dev_dbg(&client->dev, "use timer for penrelease\n");
+ hrtimer_init(&sx8654->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ sx8654->timer.function = sx865x_penrelease_timer_handler;
+ }
+
input = devm_input_allocate_device(&client->dev);
if (!input)
return -ENOMEM;
@@ -284,29 +421,31 @@ static int sx8654_probe(struct i2c_client *client,
}

error = i2c_smbus_write_byte_data(client, I2C_REG_CHANMASK,
- CONV_X | CONV_Y);
+ sx8654->data->chan_mask);
if (error) {
dev_err(&client->dev, "writing to I2C_REG_CHANMASK failed");
return error;
}

- error = i2c_smbus_write_byte_data(client, I2C_REG_IRQMASK,
- IRQ_PENTOUCH_TOUCHCONVDONE |
- IRQ_PENRELEASE);
- if (error) {
- dev_err(&client->dev, "writing to I2C_REG_IRQMASK failed");
- return error;
+ if (sx8654->data->has_reg_irqmask) {
+ error = i2c_smbus_write_byte_data(client, I2C_REG_IRQMASK,
+ IRQ_PENTOUCH_TOUCHCONVDONE |
+ IRQ_PENRELEASE);
+ if (error) {
+ dev_err(&client->dev, "writing I2C_REG_IRQMASK failed");
+ return error;
+ }
}

error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH1,
- CONDIRQ | FILT_7SA);
+ CONDIRQ | RPDNT_100K | FILT_7SA);
if (error) {
dev_err(&client->dev, "writing to I2C_REG_TOUCH1 failed");
return error;
}

error = devm_request_threaded_irq(&client->dev, client->irq,
- NULL, sx8654_irq,
+ NULL, sx8654->data->irqh,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
client->name, sx8654);
if (error) {
@@ -327,6 +466,7 @@ static int sx8654_probe(struct i2c_client *client,
}

static const struct i2c_device_id sx8654_id_table[] = {
+ { "semtech_sx8650", 0 },
{ "semtech_sx8654", 0 },
{ "semtech_sx8655", 0 },
{ "semtech_sx8656", 0 },
--
2.11.0