@@ -5,13 +5,14 @@ Required properties:
- reg : i2c device address of the chip (0x40 or 0x41)
- interrupt-parent : the phandle for the gpio controller
- interrupts : (gpio) interrupt to which the chip is connected
- - reset-gpios : gpio pin to reset the chip (active low)
- rohm,x-plate-ohms : x-plate resistance in Ohm
Optional properties:
+ - reset-gpios : gpio pin to reset the chip (active low)
- touchscreen-size-x : horizontal resolution of touchscreen (in pixels)
- touchscreen-size-y : vertical resolution of touchscreen (in pixels)
- touchscreen-max-pressure: maximum pressure value
+ - vdd-supply : power supply for the controoler
Example:
@@ -16,6 +16,7 @@
#include <linux/input/touchscreen.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/regulator/consumer.h>
#include <linux/timer.h>
/*
@@ -34,8 +35,8 @@
* HW_IDH: high 8bits of IC's ID
* HW_IDL: low 8bits of IC's ID
*/
-#define BU21029_HWID_REG (0x0E << 3)
-#define SUPPORTED_HWID 0x0229
+#define BU21029_HWID_REG (0x0E << 3)
+#define SUPPORTED_HWID 0x0229
/*
* CFR0 Register (PAGE=0, ADDR=0x00, Reset value=0x20)
@@ -49,8 +50,8 @@
* INTRM: 0 = INT output depend on "pen down" (*)
* 1 = INT output always "0"
*/
-#define BU21029_CFR0_REG (0x00 << 3)
-#define CFR0_VALUE 0x00
+#define BU21029_CFR0_REG (0x00 << 3)
+#define CFR0_VALUE 0x00
/*
* CFR1 Register (PAGE=0, ADDR=0x01, Reset value=0xA6)
@@ -65,8 +66,8 @@
* if AVE>SMPL, then AVE=SMPL (=3)
* SMPL: SMPL+1 = number of conversion samples for MAV (=7)
*/
-#define BU21029_CFR1_REG (0x01 << 3)
-#define CFR1_VALUE 0xA6
+#define BU21029_CFR1_REG (0x01 << 3)
+#define CFR1_VALUE 0xA6
/*
* CFR2 Register (PAGE=0, ADDR=0x02, Reset value=0x04)
@@ -81,8 +82,8 @@
* TIME_ST_ADC: waiting time between application of voltage
* to panel and start of A/D conversion (=100us)
*/
-#define BU21029_CFR2_REG (0x02 << 3)
-#define CFR2_VALUE 0xC9
+#define BU21029_CFR2_REG (0x02 << 3)
+#define CFR2_VALUE 0xC9
/*
* CFR3 Register (PAGE=0, ADDR=0x0B, Reset value=0x72)
@@ -102,8 +103,8 @@
* PIDAC_OFS: dual touch detection circuit adjustment, it is not necessary
* to change this from initial value
*/
-#define BU21029_CFR3_REG (0x0B << 3)
-#define CFR3_VALUE 0x42
+#define BU21029_CFR3_REG (0x0B << 3)
+#define CFR3_VALUE 0x42
/*
* LDO Register (PAGE=0, ADDR=0x0C, Reset value=0x00)
@@ -115,8 +116,8 @@
* PVDD: output voltage of panel output regulator (=2.000V)
* AVDD: output voltage of analog circuit regulator (=2.000V)
*/
-#define BU21029_LDO_REG (0x0C << 3)
-#define LDO_VALUE 0x77
+#define BU21029_LDO_REG (0x0C << 3)
+#define LDO_VALUE 0x77
/*
* Serial Interface Command Byte 1 (CID=1)
@@ -132,7 +133,7 @@
* 1 = keep power on after convert function stops
* STP: 1 = abort current conversion and power down, set to "0" automatically
*/
-#define BU21029_AUTOSCAN 0x80
+#define BU21029_AUTOSCAN 0x80
/*
* The timeout value needs to be larger than INTVL_TIME + tConv4 (sample and
@@ -140,40 +141,31 @@
* tPON + tDLY1 + (tTIME_ST_ADC + (tADC * tSMPL) * 2 + tDLY2) * 3
* see figure 8 in datasheet p15 for details of each field.
*/
-#define PEN_UP_TIMEOUT msecs_to_jiffies(50)
+#define PEN_UP_TIMEOUT_MS 50
-#define STOP_DELAY_MIN_US 50
-#define STOP_DELAY_MAX_US 1000
-#define START_DELAY_MS 2
-#define BUF_LEN 8
-#define SCALE_12BIT (1 << 12)
-#define MAX_12BIT ((1 << 12) - 1)
-#define DRIVER_NAME "bu21029"
+#define STOP_DELAY_MIN_US 50
+#define STOP_DELAY_MAX_US 1000
+#define START_DELAY_MS 2
+#define BUF_LEN 8
+#define SCALE_12BIT (1 << 12)
+#define MAX_12BIT ((1 << 12) - 1)
+#define DRIVER_NAME "bu21029"
struct bu21029_ts_data {
- struct i2c_client *client;
- struct input_dev *in_dev;
- struct timer_list timer;
- struct gpio_desc *reset_gpios;
- u32 x_plate_ohms;
- struct touchscreen_properties prop;
+ struct i2c_client *client;
+ struct input_dev *in_dev;
+ struct timer_list timer;
+ struct regulator *vdd;
+ struct gpio_desc *reset_gpios;
+ u32 x_plate_ohms;
+ struct touchscreen_properties prop;
};
-static int bu21029_touch_report(struct bu21029_ts_data *bu21029)
+static void bu21029_touch_report(struct bu21029_ts_data *bu21029, const u8 *buf)
{
- struct i2c_client *i2c = bu21029->client;
- u8 buf[BUF_LEN];
u16 x, y, z1, z2;
u32 rz;
- s32 max_pressure = bu21029->in_dev->absinfo[ABS_PRESSURE].maximum;
-
- /* read touch data and deassert INT (by restarting the autoscan mode) */
- int error = i2c_smbus_read_i2c_block_data(i2c,
- BU21029_AUTOSCAN,
- BUF_LEN,
- buf);
- if (error < 0)
- return error;
+ s32 max_pressure = input_abs_get_max(bu21029->in_dev, ABS_PRESSURE);
/*
* compose upper 8 and lower 4 bits into a 12bit value:
@@ -190,31 +182,28 @@ static int bu21029_touch_report(struct bu21029_ts_data *bu21029)
z1 = (buf[4] << 4) | (buf[5] >> 4);
z2 = (buf[6] << 4) | (buf[7] >> 4);
- if (z1 == 0 || z2 == 0)
- return 0;
-
- /*
- * calculate Rz (pressure resistance value) by equation:
- * Rz = Rx * (x/Q) * ((z2/z1) - 1), where
- * Rx is x-plate resistance,
- * Q is the touch screen resolution (8bit = 256, 12bit = 4096)
- * x, z1, z2 are the measured positions.
- */
- rz = z2 - z1;
- rz *= x;
- rz *= bu21029->x_plate_ohms;
- rz /= z1;
- rz = DIV_ROUND_CLOSEST(rz, SCALE_12BIT);
- if (rz <= max_pressure) {
- touchscreen_report_pos(bu21029->in_dev, &bu21029->prop,
- x, y, false);
- input_report_abs(bu21029->in_dev, ABS_PRESSURE,
- max_pressure - rz);
- input_report_key(bu21029->in_dev, BTN_TOUCH, 1);
- input_sync(bu21029->in_dev);
+ if (z1 && z2) {
+ /*
+ * calculate Rz (pressure resistance value) by equation:
+ * Rz = Rx * (x/Q) * ((z2/z1) - 1), where
+ * Rx is x-plate resistance,
+ * Q is the touch screen resolution (8bit = 256, 12bit = 4096)
+ * x, z1, z2 are the measured positions.
+ */
+ rz = z2 - z1;
+ rz *= x;
+ rz *= bu21029->x_plate_ohms;
+ rz /= z1;
+ rz = DIV_ROUND_CLOSEST(rz, SCALE_12BIT);
+ if (rz <= max_pressure) {
+ touchscreen_report_pos(bu21029->in_dev, &bu21029->prop,
+ x, y, false);
+ input_report_abs(bu21029->in_dev, ABS_PRESSURE,
+ max_pressure - rz);
+ input_report_key(bu21029->in_dev, BTN_TOUCH, 1);
+ input_sync(bu21029->in_dev);
+ }
}
-
- return 0;
}
static void bu21029_touch_release(struct timer_list *t)
@@ -229,32 +218,34 @@ static void bu21029_touch_release(struct timer_list *t)
static irqreturn_t bu21029_touch_soft_irq(int irq, void *data)
{
struct bu21029_ts_data *bu21029 = data;
+ u8 buf[BUF_LEN];
+ int error;
/*
- * report touch and deassert interrupt (will assert again after
+ * Read touch data and deassert interrupt (will assert again after
* INTVL_TIME + tConv4 for continuous touch)
*/
- int error = bu21029_touch_report(bu21029);
+ error = i2c_smbus_read_i2c_block_data(bu21029->client, BU21029_AUTOSCAN,
+ sizeof(buf), buf);
+ if (error < 0)
+ goto out;
- if (error)
- return IRQ_NONE;
+ bu21029_touch_report(bu21029, buf);
/* reset timer for pen up detection */
- mod_timer(&bu21029->timer, jiffies + PEN_UP_TIMEOUT);
+ mod_timer(&bu21029->timer,
+ jiffies + msecs_to_jiffies(PEN_UP_TIMEOUT_MS));
+out:
return IRQ_HANDLED;
}
-static void bu21029_stop_chip(struct input_dev *dev)
+static void bu21029_put_chip_in_reset(struct bu21029_ts_data *bu21029)
{
- struct bu21029_ts_data *bu21029 = input_get_drvdata(dev);
-
- disable_irq(bu21029->client->irq);
- del_timer_sync(&bu21029->timer);
-
- /* put chip into reset */
- gpiod_set_value_cansleep(bu21029->reset_gpios, 1);
- usleep_range(STOP_DELAY_MIN_US, STOP_DELAY_MAX_US);
+ if (bu21029->reset_gpios) {
+ gpiod_set_value_cansleep(bu21029->reset_gpios, 1);
+ usleep_range(STOP_DELAY_MIN_US, STOP_DELAY_MAX_US);
+ }
}
static int bu21029_start_chip(struct input_dev *dev)
@@ -274,23 +265,30 @@ static int bu21029_start_chip(struct input_dev *dev)
int error, i;
__be16 hwid;
+ error = regulator_enable(bu21029->vdd);
+ if (error) {
+ dev_err(&i2c->dev, "failed to power up chip: %d", error);
+ return error;
+ }
+
/* take chip out of reset */
- gpiod_set_value_cansleep(bu21029->reset_gpios, 0);
- msleep(START_DELAY_MS);
+ if (bu21029->reset_gpios) {
+ gpiod_set_value_cansleep(bu21029->reset_gpios, 0);
+ msleep(START_DELAY_MS);
+ }
- error = i2c_smbus_read_i2c_block_data(i2c,
- BU21029_HWID_REG,
- 2,
- (u8 *)&hwid);
+ error = i2c_smbus_read_i2c_block_data(i2c, BU21029_HWID_REG,
+ sizeof(hwid), (u8 *)&hwid);
if (error < 0) {
dev_err(&i2c->dev, "failed to read HW ID\n");
- goto out;
+ goto err_out;
}
if (be16_to_cpu(hwid) != SUPPORTED_HWID) {
- dev_err(&i2c->dev, "unsupported HW ID 0x%x\n", hwid);
+ dev_err(&i2c->dev,
+ "unsupported HW ID 0x%x\n", be16_to_cpu(hwid));
error = -ENODEV;
- goto out;
+ goto err_out;
}
for (i = 0; i < ARRAY_SIZE(init_table); ++i) {
@@ -299,50 +297,37 @@ static int bu21029_start_chip(struct input_dev *dev)
init_table[i].value);
if (error < 0) {
dev_err(&i2c->dev,
- "failed to write 0x%x to register 0x%x\n",
- init_table[i].value,
- init_table[i].reg);
- goto out;
+ "failed to write %#02x to register %#02x: %d\n",
+ init_table[i].value, init_table[i].reg,
+ error);
+ goto err_out;
}
}
error = i2c_smbus_write_byte(i2c, BU21029_AUTOSCAN);
if (error < 0) {
dev_err(&i2c->dev, "failed to start autoscan\n");
- goto out;
+ goto err_out;
}
enable_irq(bu21029->client->irq);
return 0;
-out:
- bu21029_stop_chip(dev);
+err_out:
+ bu21029_put_chip_in_reset(bu21029);
+ regulator_disable(bu21029->vdd);
return error;
}
-static int bu21029_parse_dt(struct bu21029_ts_data *bu21029)
+static void bu21029_stop_chip(struct input_dev *dev)
{
- struct device *dev = &bu21029->client->dev;
- int error;
-
- bu21029->reset_gpios = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
- if (IS_ERR(bu21029->reset_gpios)) {
- error = PTR_ERR(bu21029->reset_gpios);
- if (error != -EPROBE_DEFER)
- dev_err(dev, "invalid 'reset-gpios':%d\n", error);
- return error;
- }
-
- error = device_property_read_u32(dev, "rohm,x-plate-ohms",
- &bu21029->x_plate_ohms);
- if (error) {
- dev_err(dev, "invalid 'x-plate-ohms' supplied:%d\n", error);
- return error;
- }
+ struct bu21029_ts_data *bu21029 = input_get_drvdata(dev);
- touchscreen_parse_properties(bu21029->in_dev, false, &bu21029->prop);
+ disable_irq(bu21029->client->irq);
+ del_timer_sync(&bu21029->timer);
- return 0;
+ bu21029_put_chip_in_reset(bu21029);
+ regulator_disable(bu21029->vdd);
}
static int bu21029_probe(struct i2c_client *client,
@@ -365,6 +350,33 @@ static int bu21029_probe(struct i2c_client *client,
if (!bu21029)
return -ENOMEM;
+ error = device_property_read_u32(&client->dev, "rohm,x-plate-ohms",
+ &bu21029->x_plate_ohms);
+ if (error) {
+ dev_err(&client->dev,
+ "invalid 'x-plate-ohms' supplied: %d\n", error);
+ return error;
+ }
+
+ bu21029->vdd = devm_regulator_get(&client->dev, "vdd");
+ if (IS_ERR(bu21029->vdd)) {
+ error = PTR_ERR(bu21029->vdd);
+ if (error != -EPROBE_DEFER)
+ dev_err(&client->dev,
+ "failed to acquire 'vdd' supply: %d\n", error);
+ return error;
+ }
+
+ bu21029->reset_gpios = devm_gpiod_get_optional(&client->dev,
+ "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(bu21029->reset_gpios)) {
+ error = PTR_ERR(bu21029->reset_gpios);
+ if (error != -EPROBE_DEFER)
+ dev_err(&client->dev,
+ "failed to acquire 'reset' gpio: %d\n", error);
+ return error;
+ }
+
in_dev = devm_input_allocate_device(&client->dev);
if (!in_dev) {
dev_err(&client->dev, "unable to allocate input device\n");
@@ -372,42 +384,36 @@ static int bu21029_probe(struct i2c_client *client,
}
bu21029->client = client;
- bu21029->in_dev = in_dev;
+ bu21029->in_dev = in_dev;
timer_setup(&bu21029->timer, bu21029_touch_release, 0);
- in_dev->name = DRIVER_NAME;
- in_dev->id.bustype = BUS_I2C;
- in_dev->open = bu21029_start_chip;
- in_dev->close = bu21029_stop_chip;
+ in_dev->name = DRIVER_NAME;
+ in_dev->id.bustype = BUS_I2C;
+ in_dev->open = bu21029_start_chip;
+ in_dev->close = bu21029_stop_chip;
input_set_capability(in_dev, EV_KEY, BTN_TOUCH);
input_set_abs_params(in_dev, ABS_X, 0, MAX_12BIT, 0, 0);
input_set_abs_params(in_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
input_set_abs_params(in_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
-
- error = bu21029_parse_dt(bu21029);
- if (error)
- return error;
+ touchscreen_parse_properties(in_dev, false, &bu21029->prop);
input_set_drvdata(in_dev, bu21029);
- error = devm_request_threaded_irq(&client->dev,
- client->irq,
- NULL,
- bu21029_touch_soft_irq,
- IRQF_ONESHOT,
- DRIVER_NAME,
- bu21029);
+ irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
+ error = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, bu21029_touch_soft_irq,
+ IRQF_ONESHOT, DRIVER_NAME, bu21029);
if (error) {
- dev_err(&client->dev, "unable to request touch irq\n");
+ dev_err(&client->dev,
+ "unable to request touch irq: %d\n", error);
return error;
}
- bu21029_stop_chip(in_dev);
-
error = input_register_device(in_dev);
if (error) {
- dev_err(&client->dev, "unable to register input device\n");
+ dev_err(&client->dev,
+ "unable to register input device: %d\n", error);
return error;
}
@@ -416,24 +422,17 @@ static int bu21029_probe(struct i2c_client *client,
return 0;
}
-static int bu21029_remove(struct i2c_client *client)
-{
- struct bu21029_ts_data *bu21029 = i2c_get_clientdata(client);
-
- bu21029_stop_chip(bu21029->in_dev);
-
- return 0;
-}
-
static int __maybe_unused bu21029_suspend(struct device *dev)
{
struct i2c_client *i2c = to_i2c_client(dev);
struct bu21029_ts_data *bu21029 = i2c_get_clientdata(i2c);
- mutex_lock(&bu21029->in_dev->mutex);
- if (bu21029->in_dev->users)
- bu21029_stop_chip(bu21029->in_dev);
- mutex_unlock(&bu21029->in_dev->mutex);
+ if (!device_may_wakeup(dev)) {
+ mutex_lock(&bu21029->in_dev->mutex);
+ if (bu21029->in_dev->users)
+ bu21029_stop_chip(bu21029->in_dev);
+ mutex_unlock(&bu21029->in_dev->mutex);
+ }
return 0;
}
@@ -443,29 +442,39 @@ static int __maybe_unused bu21029_resume(struct device *dev)
struct i2c_client *i2c = to_i2c_client(dev);
struct bu21029_ts_data *bu21029 = i2c_get_clientdata(i2c);
- mutex_lock(&bu21029->in_dev->mutex);
- if (bu21029->in_dev->users)
- bu21029_start_chip(bu21029->in_dev);
- mutex_unlock(&bu21029->in_dev->mutex);
+ if (!device_may_wakeup(dev)) {
+ mutex_lock(&bu21029->in_dev->mutex);
+ if (bu21029->in_dev->users)
+ bu21029_start_chip(bu21029->in_dev);
+ mutex_unlock(&bu21029->in_dev->mutex);
+ }
return 0;
}
static SIMPLE_DEV_PM_OPS(bu21029_pm_ops, bu21029_suspend, bu21029_resume);
static const struct i2c_device_id bu21029_ids[] = {
- {DRIVER_NAME, 0},
- {}
+ { DRIVER_NAME, 0 },
+ { /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, bu21029_ids);
+#ifdef CONFIG_OF
+static const struct of_device_id bu21029_of_ids[] = {
+ { .compatible = "rohm,bu21029" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bu21029_of_ids);
+#endif
+
static struct i2c_driver bu21029_driver = {
- .driver = {
- .name = DRIVER_NAME,
- .pm = &bu21029_pm_ops,
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = of_match_ptr(bu21029_of_ids),
+ .pm = &bu21029_pm_ops,
},
- .id_table = bu21029_ids,
- .probe = bu21029_probe,
- .remove = bu21029_remove,
+ .id_table = bu21029_ids,
+ .probe = bu21029_probe,
};
module_i2c_driver(bu21029_driver);