Hi Michael, On Sat, Oct 12, 2019 at 09:27:38PM +0200, michael.srba@xxxxxxxxx wrote: > From: Michael Srba <Michael.Srba@xxxxxxxxx> > > Add support for the bt541 touchscreen IC from zinitix, loosely based > on downstream driver. The driver currently supports multitouch (5 touch points). > The bt541 seems to support touch keys, but the support was not added because > that functionality is not being utilized by the touchscreen used for testing. > Based on the similartities between downstream drivers, it seems likely that > other similar touchscreen ICs can be supported with this driver in the future. > > Signed-off-by: Michael Srba <Michael.Srba@xxxxxxxxx> > --- > bt541 is used in the Samsung Galaxy A3 (2015) that has recently gained > mainline support [1]. > > The downstream driver this is loosely based on: > https://github.com/msm8916-mainline/android_kernel_qcom_msm8916/tree/SM-A300FU/drivers/input/touchscreen/zinitix > > [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1329c1ab0730b521e6cd3051c56a2ff3d55f21e6 > > drivers/input/touchscreen/Kconfig | 12 + > drivers/input/touchscreen/Makefile | 1 + > drivers/input/touchscreen/zinitix.c | 508 ++++++++++++++++++++++++++++ > 3 files changed, 521 insertions(+) > create mode 100644 drivers/input/touchscreen/zinitix.c > > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig > index 46ad9090493b..6203e0764d5f 100644 > --- a/drivers/input/touchscreen/Kconfig > +++ b/drivers/input/touchscreen/Kconfig > @@ -1314,4 +1314,16 @@ config TOUCHSCREEN_IQS5XX > To compile this driver as a module, choose M here: the > module will be called iqs5xx. > > +config TOUCHSCREEN_ZINITIX > + tristate "Zinitix touchscreen support" > + depends on I2C > + help > + Say Y here if you have a touchscreen using Zinitix bt541, > + or something similar enough. > + > + If unsure, say N. > + > + To compile this driver as a module, choose M here: the > + module will be called zinitix. > + > endif > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile > index 94c6162409b3..bafe9d76ed03 100644 > --- a/drivers/input/touchscreen/Makefile > +++ b/drivers/input/touchscreen/Makefile > @@ -110,3 +110,4 @@ obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50) += colibri-vf50-ts.o > obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023) += rohm_bu21023.o > obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_FW) += raspberrypi-ts.o > obj-$(CONFIG_TOUCHSCREEN_IQS5XX) += iqs5xx.o > +obj-$(CONFIG_TOUCHSCREEN_ZINITIX) += zinitix.o > diff --git a/drivers/input/touchscreen/zinitix.c b/drivers/input/touchscreen/zinitix.c > new file mode 100644 > index 000000000000..55b1816b39d4 > --- /dev/null > +++ b/drivers/input/touchscreen/zinitix.c > @@ -0,0 +1,508 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +#include <linux/kernel.h> > +#include <linux/i2c.h> > +#include <linux/input.h> > +#include <linux/input/mt.h> > +#include <linux/input/touchscreen.h> > +#include <linux/module.h> > +#include <linux/delay.h> > +#include <linux/irq.h> > +#include <linux/interrupt.h> > +#include <linux/regulator/consumer.h> > +#include <linux/slab.h> > +#include <linux/of.h> > +#include <asm/unaligned.h> > + > +/* Register Map */ > + > +#define BT541_SWRESET_CMD 0x0000 > +#define BT541_WAKEUP_CMD 0x0001 > + > +#define BT541_IDLE_CMD 0x0004 > +#define BT541_SLEEP_CMD 0x0005 > + > +#define BT541_CLEAR_INT_STATUS_CMD 0x0003 > +#define BT541_CALIBRATE_CMD 0x0006 > +#define BT541_SAVE_STATUS_CMD 0x0007 > +#define BT541_SAVE_CALIBRATION_CMD 0x0008 > +#define BT541_RECALL_FACTORY_CMD 0x000f > + > +#define BT541_THRESHOLD 0x0020 > + > +#define BT541_LARGE_PALM_REJECT_AREA_TH 0x003F > + > +#define BT541_DEBUG_REG 0x0115 /* 0~7 */ > + > +#define BT541_TOUCH_MODE 0x0010 > +#define BT541_CHIP_REVISION 0x0011 > +#define BT541_FIRMWARE_VERSION 0x0012 > + > +#define ZINITIX_USB_DETECT 0x116 > + > +#define BT541_MINOR_FW_VERSION 0x0121 > + > +#define BT541_VENDOR_ID 0x001C > +#define BT541_HW_ID 0x0014 > + > +#define BT541_DATA_VERSION_REG 0x0013 > +#define BT541_SUPPORTED_FINGER_NUM 0x0015 > +#define BT541_EEPROM_INFO 0x0018 > +#define BT541_INITIAL_TOUCH_MODE 0x0019 > + > +#define BT541_TOTAL_NUMBER_OF_X 0x0060 > +#define BT541_TOTAL_NUMBER_OF_Y 0x0061 > + > +#define BT541_DELAY_RAW_FOR_HOST 0x007f > + > +#define BT541_BUTTON_SUPPORTED_NUM 0x00B0 > +#define BT541_BUTTON_SENSITIVITY 0x00B2 > +#define BT541_DUMMY_BUTTON_SENSITIVITY 0X00C8 > + > +#define BT541_X_RESOLUTION 0x00C0 > +#define BT541_Y_RESOLUTION 0x00C1 > + > +#define BT541_POINT_STATUS_REG 0x0080 > +#define BT541_ICON_STATUS_REG 0x00AA > + > +#define BT541_POINT_COORD_REG (BT541_POINT_STATUS_REG + 2) > + > +#define BT541_AFE_FREQUENCY 0x0100 > +#define BT541_DND_N_COUNT 0x0122 > +#define BT541_DND_U_COUNT 0x0135 > + > +#define BT541_RAWDATA_REG 0x0200 > + > +#define BT541_EEPROM_INFO_REG 0x0018 > + > +#define BT541_INT_ENABLE_FLAG 0x00f0 > +#define BT541_PERIODICAL_INTERRUPT_INTERVAL 0x00f1 > + > +#define BT541_BTN_WIDTH 0x016d > + > +#define BT541_CHECKSUM_RESULT 0x012c > + > +#define BT541_INIT_FLASH 0x01d0 > +#define BT541_WRITE_FLASH 0x01d1 > +#define BT541_READ_FLASH 0x01d2 > + > +#define ZINITIX_INTERNAL_FLAG_02 0x011e > +#define ZINITIX_INTERNAL_FLAG_03 0x011f > + > +#define ZINITIX_I2C_CHECKSUM_WCNT 0x016a > +#define ZINITIX_I2C_CHECKSUM_RESULT 0x016c > + > +/* Interrupt & status register flags */ > + > +#define BIT_PT_CNT_CHANGE BIT(0) > +#define BIT_DOWN BIT(1) > +#define BIT_MOVE BIT(2) > +#define BIT_UP BIT(3) > +#define BIT_PALM BIT(4) > +#define BIT_PALM_REJECT BIT(5) > +#define BIT_RESERVED_0 BIT(6) > +#define BIT_RESERVED_1 BIT(7) > +#define BIT_WEIGHT_CHANGE BIT(8) > +#define BIT_PT_NO_CHANGE BIT(9) > +#define BIT_REJECT BIT(10) > +#define BIT_PT_EXIST BIT(11) > +#define BIT_RESERVED_2 BIT(12) > +#define BIT_ERROR BIT(13) > +#define BIT_DEBUG BIT(14) > +#define BIT_ICON_EVENT BIT(15) > + > +#define SUB_BIT_EXIST BIT(0) > +#define SUB_BIT_DOWN BIT(1) > +#define SUB_BIT_MOVE BIT(2) > +#define SUB_BIT_UP BIT(3) > +#define SUB_BIT_UPDATE BIT(4) > +#define SUB_BIT_WAIT BIT(5) > + > +#define TOUCH_POINT_MODE 1 > +#define MAX_SUPPORTED_FINGER_NUM 5 > + > +#define CHIP_ON_DELAY 15 // ms > +#define FIRMWARE_ON_DELAY 40 // ms > + > +#define DELAY_FOR_TRANSACTION 50 // μs > +#define DELAY_FOR_POST_TRANSCATION 10 // μs > + > +struct point_coord { > + __le16 x; > + __le16 y; > + u8 width; > + u8 sub_status; > + // not used on this model, but needed as padding: > + u8 minor_width; > + u8 angle; > +} __packed; I do not think you need to declare this as packed. > + > +struct point_status { > + __le16 status; > + __le16 event_flag; > +} __packed; And neither this. > + > +struct bt541_ts_data { > + struct i2c_client *client; > + struct input_dev *input_dev; > + struct touchscreen_properties prop; > + struct regulator_bulk_data supplies[2]; > +}; > + > +static inline s32 zinitix_read_data(struct i2c_client *client, No need to mark it inline, let's trust the compiler to do its job. Also, it returns error code or 0, just use int for return type and not s32. > + u16 reg, u8 *values, u16 length) Why exactly u16 for length and not int or size_t? > +{ > + int ret; Let's call it "error" here and elsewhere. > + __le16 reg_le = cpu_to_le16(reg); > + > + ret = i2c_master_send(client, (u8 *)®_le, sizeof(reg_le)); > + if (ret < 0) > + return ret; > + > + udelay(DELAY_FOR_TRANSACTION); > + ret = i2c_master_recv(client, values, length); > + if (ret < 0) Ideally we check that if ret >= 0 but ret != length we return -EIO. > + return ret; > + > + udelay(DELAY_FOR_POST_TRANSCATION); > + return 0; > +} > + > +static inline s32 zinitix_write_data(struct i2c_client *client, > + u16 reg, u8 *values, u16 length) > +{ > + int ret; > + u8 *packet; > + __le16 reg_le = cpu_to_le16(reg); > + > + packet = kmalloc(length + sizeof(reg_le), GFP_KERNEL); Need to handle memory allocation error; > + memcpy(packet, (u8 *)®_le, sizeof(reg_le)); > + memcpy(packet + sizeof(reg_le), values, length); > + > + ret = i2c_master_send(client, packet, length + sizeof(reg_le)); Since you kmalloc()ed the data you can use _dmasafe() here. > + kfree(packet); > + if (ret < 0) > + return ret; > + > + udelay(DELAY_FOR_POST_TRANSCATION); > + return 0; > +} > + > +static inline s32 zinitix_write_u16(struct i2c_client *client, u16 reg, u16 value) > +{ > + __le16 value_le = cpu_to_le16(value); > + > + return zinitix_write_data(client, reg, (u8 *)&value_le, sizeof(reg)); > +} > + > +static inline s32 zinitix_write_cmd(struct i2c_client *client, u16 reg) > +{ > + int ret; > + __le16 reg_le = cpu_to_le16(reg); > + > + ret = i2c_master_send(client, (u8 *)®_le, sizeof(reg_le)); > + if (ret < 0) > + return ret; > + > + udelay(DELAY_FOR_POST_TRANSCATION); > + return 0; > +} > + > +static bool zinitix_init_touch(struct bt541_ts_data *bt541) > +{ > + struct i2c_client *client = bt541->client; > + int i; > + int ret; > + > + ret = zinitix_write_cmd(client, BT541_SWRESET_CMD); > + if (ret) { > + dev_err(&client->dev, "Failed to write reset command\n"); > + return ret; > + } > + > + ret = zinitix_write_u16(client, BT541_INT_ENABLE_FLAG, 0x0); > + if (ret) { > + dev_err(&client->dev, "failed to reset interrupt enable flag\n"); > + return ret; > + } > + > + /* initialize */ > + ret = zinitix_write_u16(client, BT541_X_RESOLUTION, (u16)bt541->prop.max_x); > + if (ret) > + return ret; > + > + ret = zinitix_write_u16(client, BT541_Y_RESOLUTION, (u16)bt541->prop.max_y); > + if (ret) > + return ret; > + > + ret = zinitix_write_u16(client, BT541_SUPPORTED_FINGER_NUM, > + (u16)MAX_SUPPORTED_FINGER_NUM); > + if (ret) > + return ret; > + > + ret = zinitix_write_u16(client, BT541_INITIAL_TOUCH_MODE, TOUCH_POINT_MODE); > + if (ret) > + return ret; > + > + ret = zinitix_write_u16(client, BT541_TOUCH_MODE, TOUCH_POINT_MODE); > + if (ret) > + return ret; > + > + ret = zinitix_write_u16(client, BT541_INT_ENABLE_FLAG, > + BIT_PT_CNT_CHANGE | BIT_DOWN | BIT_MOVE | BIT_UP); > + if (ret) > + return ret; > + > + /* clear queue */ > + for (i = 0; i < 10; i++) { > + zinitix_write_cmd(client, BT541_CLEAR_INT_STATUS_CMD); > + udelay(10); > + } > + > + return 0; > +} > + > +static int zinitix_init_regulators(struct bt541_ts_data *bt541) > +{ > + struct i2c_client *client = bt541->client; > + int ret; > + > + bt541->supplies[0].supply = "vdd"; > + bt541->supplies[1].supply = "vddo"; > + ret = devm_regulator_bulk_get(&client->dev, ARRAY_SIZE(bt541->supplies), > + bt541->supplies); > + if (ret < 0) { > + dev_err(&client->dev, "Failed to get regulators: %d\n", ret); > + return ret; > + } > + > + return 0; > +} > + > +static int zinitix_send_power_on_sequence(struct bt541_ts_data *bt541) > +{ > + int ret; > + struct i2c_client *client = bt541->client; > + > + ret = zinitix_write_u16(client, 0xc000, 0x0001); > + if (ret) { > + dev_err(&client->dev, "Failed to send power sequence(vendor cmd enable)\n"); > + return ret; > + } > + udelay(10); > + > + ret = zinitix_write_cmd(client, 0xc004); > + if (ret) { > + dev_err(&client->dev, "Failed to send power sequence(intn clear)\n"); > + return ret; > + } > + udelay(10); > + > + ret = zinitix_write_u16(client, 0xc002, 0x0001); > + if (ret) { > + dev_err(&client->dev, "Failed to send power sequence(nvm init)\n"); > + return ret; > + } > + mdelay(2); > + > + ret = zinitix_write_u16(client, 0xc001, 0x0001); > + if (ret) { > + dev_err(&client->dev, "Failed to send power sequence(program start)\n"); > + return ret; > + } > + msleep(FIRMWARE_ON_DELAY); /* wait for checksum cal */ > + > + return 0; > +} > + > +static irqreturn_t zinitix_ts_irq_handler(int irq, void *bt541_handler) > +{ > + struct bt541_ts_data *bt541 = (struct bt541_ts_data *)bt541_handler; > + struct i2c_client *client = bt541->client; > + int i; > + int ret; > + struct point_status point_status; > + struct point_coord point_coord[MAX_SUPPORTED_FINGER_NUM] = {0}; > + > + memset(&point_status, 0, sizeof(struct point_status)); > + > + ret = zinitix_read_data(bt541->client, BT541_POINT_STATUS_REG, > + (u8 *)&point_status, sizeof(struct point_status)); > + if (ret) { > + dev_err(&client->dev, "%s: Failed to read point status\n", __func__); goto out; > + > + zinitix_write_cmd(bt541->client, BT541_CLEAR_INT_STATUS_CMD); > + return IRQ_HANDLED; Combine this with normal exit code flow. > + } > + > + for (i = 0; i < MAX_SUPPORTED_FINGER_NUM; i++) { > + if (!(le16_to_cpu(point_status.event_flag) & BIT(i))) I'd do le->cpu conversion outside the loop, and then use for_each_set_bit(...). > + continue; > + > + ret = zinitix_read_data(bt541->client, BT541_POINT_COORD_REG + > + (i * sizeof(struct point_coord) / sizeof(u16)), > + (u8 *)&point_coord[i], sizeof(struct point_coord)); > + if (ret) { > + dev_err(&client->dev, "%s: Failed to read point info\n", __func__); > + > + zinitix_write_cmd(bt541->client, BT541_CLEAR_INT_STATUS_CMD); > + return IRQ_HANDLED; > + } > + > + if (!(point_coord[i].sub_status & SUB_BIT_EXIST)) > + continue; > + > + input_mt_slot(bt541->input_dev, i); > + input_mt_report_slot_state(bt541->input_dev, MT_TOOL_FINGER, true); > + touchscreen_report_pos(bt541->input_dev, &bt541->prop, > + le16_to_cpu(point_coord[i].x), > + le16_to_cpu(point_coord[i].y), true); > + input_report_abs(bt541->input_dev, ABS_MT_TOUCH_MAJOR, point_coord[i].width); > + input_report_abs(bt541->input_dev, ABS_MT_WIDTH_MAJOR, point_coord[i].width); Why do you report both? I think ABS_MT_TOUCH_MAJOR should be enough. > + } > + > + zinitix_write_cmd(bt541->client, BT541_CLEAR_INT_STATUS_CMD); > + > + input_mt_sync_frame(bt541->input_dev); > + input_sync(bt541->input_dev); > + > + return IRQ_HANDLED; > +} > + > +static int zinitix_init_input_dev(struct bt541_ts_data *bt541) > +{ > + int ret; > + > + bt541->input_dev = devm_input_allocate_device(&bt541->client->dev); > + if (!bt541->input_dev) { > + dev_err(&bt541->client->dev, "Failed to allocate input device."); > + return -ENOMEM; > + } > + > + bt541->input_dev->name = "Zinitix Capacitive TouchScreen"; > + bt541->input_dev->phys = "input/ts"; > + bt541->input_dev->id.bustype = BUS_I2C; > + > + input_set_capability(bt541->input_dev, EV_ABS, ABS_MT_POSITION_X); > + input_set_capability(bt541->input_dev, EV_ABS, ABS_MT_POSITION_Y); > + input_set_abs_params(bt541->input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0); > + input_set_abs_params(bt541->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0); > + > + touchscreen_parse_properties(bt541->input_dev, true, &bt541->prop); > + > + if (!bt541->prop.max_x || !bt541->prop.max_y) { > + dev_err(&bt541->client->dev, "touchscreen-size-x and/or touchscreen-size-y not set in dts\n"); > + return -EINVAL; > + } > + > + ret = input_mt_init_slots(bt541->input_dev, MAX_SUPPORTED_FINGER_NUM, > + INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); > + if (ret) { > + dev_err(&bt541->client->dev, > + "Failed to initialize MT slots: %d", ret); > + return ret; > + } > + > + ret = input_register_device(bt541->input_dev); > + if (ret) { > + dev_err(&bt541->client->dev, > + "Failed to register input device: %d", ret); > + return ret; > + } > + > + return 0; > +} > + > +static int zinitix_ts_probe(struct i2c_client *client, const struct i2c_device_id *id) > +{ > + struct bt541_ts_data *bt541; > + int ret; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { > + dev_err(&client->dev, "I2C check functionality failed.\n"); > + return -ENXIO; > + } > + > + bt541 = devm_kzalloc(&client->dev, sizeof(*bt541), GFP_KERNEL); > + if (!bt541) > + return -ENOMEM; > + > + bt541->client = client; > + i2c_set_clientdata(client, bt541); > + > + ret = zinitix_init_regulators(bt541); > + if (ret) { > + dev_err(&client->dev, "regulator initialization failed: %d\n", ret); > + return ret; > + } > + > + ret = regulator_bulk_enable(ARRAY_SIZE(bt541->supplies), bt541->supplies); > + if (ret < 0) { > + dev_err(&client->dev, "Failed to enable regulators: %d\n", ret); > + return ret; > + } > + > + msleep(CHIP_ON_DELAY); > + > + ret = zinitix_send_power_on_sequence(bt541); > + if (ret) { > + dev_err(&client->dev, "sending power-on sequence failed: %d\n", ret); > + return ret; > + } > + > + ret = zinitix_init_input_dev(bt541); > + if (ret) { > + dev_err(&client->dev, "input dev initialization failed: %d\n", ret); > + return ret; > + } > + > + ret = zinitix_init_touch(bt541); > + if (ret) { > + dev_err(&client->dev, "Failed to init touchscreen ic\n"); > + return ret; > + } > + > + ret = devm_request_threaded_irq(&bt541->client->dev, bt541->client->irq, > + NULL, zinitix_ts_irq_handler, > + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, > + bt541->client->name, bt541); > + if (ret) { > + dev_err(&client->dev, "request IRQ failed: %d\n", ret); > + return ret; > + } > + > + dev_info(&client->dev, "initialized a zinitix touchscreen\n"); > + > + return 0; > +} > + > +static int zinitix_ts_remove(struct i2c_client *client) > +{ > + struct bt541_ts_data *bt541 = i2c_get_clientdata(client); > + > + regulator_bulk_disable(ARRAY_SIZE(bt541->supplies), bt541->supplies); Doing it here means you cut off power to the device while interrupts are still enabled, etc. Unfortunately we do not have devm interface for disabling regulators. Please use devm_add_action_or_reset() in zinitix_ts_probe() and install a custom handler calling regulator_bulk_disable() and drop zinitix_ts_remove(). > + > + return 0; > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id zinitix_of_match[] = { > + { .compatible = "zinitix,bt541" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, zinitix_of_match); > +#endif > + > +static struct i2c_driver zinitix_ts_driver = { > + .probe = zinitix_ts_probe, > + .remove = zinitix_ts_remove, > + .driver = { > + .name = "Zinitix-TS", > + .of_match_table = of_match_ptr(zinitix_of_match), > + }, > +}; > +module_i2c_driver(zinitix_ts_driver); > + > +MODULE_AUTHOR("Michael Srba <Michael.Srba@xxxxxxxxx>"); > +MODULE_DESCRIPTION("Zinitix touchscreen driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.23.0 > Thanks. -- Dmitry
