Hi Chris,
Thank you for your patch.
On Mon, Oct 10, 2022 at 10:35, Chris Morgan <macroalpha82@xxxxxxxxx> wrote:
> From: Chris Morgan <macromorgan@xxxxxxxxxxx>
>
> Add support for the Hynitron cst3xx controller found on devices such
> as the Anbernic RG353P and RG353V (the Hynitron CST340). This driver
> was built from sources provided by Hynitron to Anbernic (possibly
> via Rockchip as an intermediary) and marked as GPLv2 in the code.
> This driver was written strictly for the cst3xx series, but in
> most places was left somewhat generic so support could be easily
> added to other devices in the future.
>
> Signed-off-by: Chris Morgan <macromorgan@xxxxxxxxxxx>
> ---
> drivers/input/touchscreen/Kconfig | 12 +
> drivers/input/touchscreen/Makefile | 1 +
> drivers/input/touchscreen/hynitron_cstxxx.c | 508 ++++++++++++++++++++
> 3 files changed, 521 insertions(+)
> create mode 100644 drivers/input/touchscreen/hynitron_cstxxx.c
>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 2d70c945b20a..9a9528e59c36 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -422,6 +422,18 @@ config TOUCHSCREEN_HYCON_HY46XX
> To compile this driver as a module, choose M here: the
> module will be called hycon-hy46xx.
>
> +config TOUCHSCREEN_HYNITRON_CSTXXX
> + tristate "Hynitron touchscreen support"
> + depends on I2C
Since we include linux/of.h, I think we should also add:
depends on OF
There are some small nitpicks below as well.
With those addressed, please add:
Reviewed-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxxxx>
> + help
> + Say Y here if you have a touchscreen using a Hynitron
> + touchscreen controller.
> +
> + If unsure, say N.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called hynitron-cstxxx.
> +
> config TOUCHSCREEN_ILI210X
> tristate "Ilitek ILI210X based touchscreen"
> depends on I2C
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 557f84fd2075..43860ca19b98 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -47,6 +47,7 @@ obj-$(CONFIG_TOUCHSCREEN_EXC3000) += exc3000.o
> obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o
> obj-$(CONFIG_TOUCHSCREEN_GOODIX) += goodix_ts.o
> obj-$(CONFIG_TOUCHSCREEN_HIDEEP) += hideep.o
> +obj-$(CONFIG_TOUCHSCREEN_HYNITRON_CSTXXX) += hynitron_cstxxx.o
> obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.o
> obj-$(CONFIG_TOUCHSCREEN_ILITEK) += ilitek_ts_i2c.o
> obj-$(CONFIG_TOUCHSCREEN_IMAGIS) += imagis.o
> diff --git a/drivers/input/touchscreen/hynitron_cstxxx.c b/drivers/input/touchscreen/hynitron_cstxxx.c
> new file mode 100644
> index 000000000000..11701ff39eb1
> --- /dev/null
> +++ b/drivers/input/touchscreen/hynitron_cstxxx.c
> @@ -0,0 +1,508 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Driver for Hynitron cstxxx Touchscreen
> + *
> + * Copyright (c) 2022 Chris Morgan <macromorgan@xxxxxxxxxxx>
> + *
> + * This code is based on hynitron_core.c authored by Hynitron.
> + * Note that no datasheet was available, so much of these registers
> + * are undocumented. This is essentially a cleaned-up version of the
> + * vendor driver with support removed for hardware I cannot test and
> + * device-specific functions replated with generic functions wherever
> + * possible.
> + */
> +
> +#include <asm/unaligned.h>
> +#include <linux/delay.h>
> +#include <linux/gpio.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/of.h>
> +#include <linux/of_device.h>
> +
> +/* Per chip data */
> +struct hynitron_ts_chip_data {
> + unsigned int max_touch_num;
> + u32 ic_chkcode;
> + int (*firmware_info)(struct i2c_client *client);
> + int (*bootloader_enter)(struct i2c_client *client);
> + int (*init_input)(struct i2c_client *client);
> + void (*report_touch)(struct i2c_client *client);
> +};
> +
> +/* Data generic to all (supported and non-supported) controllers. */
> +struct hynitron_ts_data {
> + const struct hynitron_ts_chip_data *pdata;
> + struct i2c_client *client;
> + struct input_dev *input_dev;
> + struct touchscreen_properties prop;
> + struct gpio_desc *reset_gpio;
> + struct gpio_desc *irq_gpio;
> +};
> +
> +/*
> + * Since I have no datasheet, these values are guessed and/or assumed
> + * based on observation and testing.
> + */
> +#define CST3XX_FIRMWARE_INFO_START_CMD 0x01d1
> +#define CST3XX_FIRMWARE_INFO_END_CMD 0x09d1
> +#define CST3XX_FIRMWARE_CHK_CODE_REG 0xfcd1
> +#define CST3XX_FIRMWARE_VERSION_REG 0x08d2
> +#define CST3XX_FIRMWARE_VER_INVALID_VAL 0xa5a5a5a5
> +
> +#define CST3XX_BOOTLDR_PROG_CMD 0xaa01a0
> +#define CST3XX_BOOTLDR_PROG_CHK_REG 0x02a0
> +#define CST3XX_BOOTLDR_CHK_VAL 0xac
> +
> +#define CST3XX_TOUCH_DATA_PART_REG 0x00d0
> +#define CST3XX_TOUCH_DATA_FULL_REG 0x07d0
> +#define CST3XX_TOUCH_DATA_CHK_VAL 0xab
> +#define CST3XX_TOUCH_DATA_TOUCH_VAL 0x03
> +#define CST3XX_TOUCH_DATA_STOP_CMD 0xab00d0
> +#define CST3XX_TOUCH_COUNT_MASK GENMASK(6, 0)
> +
> +
> +/*
> + * Hard coded reset delay value of 20ms not IC dependent in
> + * vendor driver.
> + */
> +static void hyn_reset_proc(struct i2c_client *client, int delay)
> +{
> + struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
> +
> + gpiod_set_value_cansleep(ts_data->reset_gpio, 1);
> + mdelay(20);
> + gpiod_set_value_cansleep(ts_data->reset_gpio, 0);
> + if (delay)
> + mdelay(delay);
> +}
> +
> +static irqreturn_t hyn_interrupt_handler(int irq, void *dev_id)
> +{
> + struct i2c_client *client = dev_id;
> + struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
> +
> + ts_data->pdata->report_touch(client);
> +
> + return IRQ_HANDLED;
> +}
> +
> +/*
> + * The vendor driver would retry twice before failing to read or write
> + * to the i2c device.
> + */
> +
> +static int cst3xx_i2c_write(struct i2c_client *client,
> + unsigned char *buf, int len)
> +{
> + int ret;
> + int retries = 0;
> +
> + while (retries < 2) {
> + ret = i2c_master_send(client, buf, len);
> + if (ret == len)
> + return 0;
> + if (ret <= 0)
> + retries++;
> + else
> + break;
> + }
> +
> + return ret < 0 ? ret : -EIO;
> +}
> +
> +static int cst3xx_i2c_read_register(struct i2c_client *client, u16 reg,
> + u8 *val, u16 len)
> +{
> + __le16 buf = cpu_to_le16(reg);
> + struct i2c_msg msgs[] = {
> + {
> + .addr = client->addr,
> + .flags = 0,
> + .len = 2,
> + .buf = (u8 *)&buf,
> + },
> + {
> + .addr = client->addr,
> + .flags = I2C_M_RD,
> + .len = len,
> + .buf = val,
> + }
> + };
> + int ret;
> +
> + ret = i2c_transfer(client->adapter, msgs, 2);
> + if (ret >= 0)
> + ret = (ret == ARRAY_SIZE(msgs) ? 0 : -EIO);
> +
> + if (ret)
> + dev_err(&client->dev,
> + "Error reading %d bytes from 0x%04x: %d\n",
> + len, reg, ret);
This could be a single line, since column limit is 100chars now. This
applies for a lot of other wrapped lines in this file.
Please consider joining such lines to reduce the overall line count.
> +
> + return ret;
> +}
> +
> +static int cst3xx_firmware_info(struct i2c_client *client)
> +{
> + struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
> + int ret;
> + u32 tmp;
> + unsigned char buf[4];
> +
> + /*
> + * Tests suggest this command needed to read firmware regs.
> + */
> + put_unaligned_le16(CST3XX_FIRMWARE_INFO_START_CMD, buf);
> + ret = cst3xx_i2c_write(client, buf, 2);
> + if (ret < 0)
> + return -EIO;
> +
> + mdelay(10);
> +
> + /*
> + * Read register for check-code to determine if device detected
> + * correctly.
> + */
> + ret = cst3xx_i2c_read_register(client, CST3XX_FIRMWARE_CHK_CODE_REG,
> + buf, 4);
> + if (ret < 0)
> + return -EIO;
> +
> + tmp = get_unaligned_le32(buf);
> + if ((tmp & 0xffff0000) != ts_data->pdata->ic_chkcode) {
> + dev_err(&client->dev, "%s ic mismatch\n", __func__);
Should we print the device's ic_chkcode in case we don't recognize it?
> + return -ENODEV;
> + }
> +
> + mdelay(10);
> +
> + /* Read firmware version and test if firmware missing. */
> + ret = cst3xx_i2c_read_register(client, CST3XX_FIRMWARE_VERSION_REG,
> + buf, 4);
> + if (ret < 0)
> + return -EIO;
> +
> + tmp = get_unaligned_le32(buf);
> + if (tmp == CST3XX_FIRMWARE_VER_INVALID_VAL) {
> + dev_err(&client->dev, "Device firmware missing\n");
> + return -ENODEV;
> + }
> +
> + /*
> + * Tests suggest cmd required to exit reading firmware regs.
> + */
> + put_unaligned_le16(CST3XX_FIRMWARE_INFO_END_CMD, buf);
> + ret = cst3xx_i2c_write(client, buf, 2);
> + if (ret < 0)
> + return -EIO;
> +
> + mdelay(5);
> +
> + return 0;
> +}
> +
> +static int cst3xx_bootloader_enter(struct i2c_client *client)
> +{
> + int ret;
> + u8 retry;
> + u32 tmp;
> + unsigned char buf[3];
> +
> + for (retry = 0; retry < 5; retry++) {
> + hyn_reset_proc(client, (7 + retry));
> + /* set cmd to enter program mode */
> + put_unaligned_le24(CST3XX_BOOTLDR_PROG_CMD, buf);
> + ret = cst3xx_i2c_write(client, buf, 3);
> + if (ret < 0)
> + continue;
> + mdelay(2);
> +
> + /* check whether in program mode */
> + ret = cst3xx_i2c_read_register(client,
> + CST3XX_BOOTLDR_PROG_CHK_REG,
> + buf, 1);
> + tmp = get_unaligned(buf);
> +
> + if (ret < 0)
> + continue;
> +
> + if (tmp == CST3XX_BOOTLDR_CHK_VAL)
> + break;
> + }
> +
> + if (tmp != CST3XX_BOOTLDR_CHK_VAL) {
> + dev_err(&client->dev, "%s unable to enter bootloader mode\n",
> + __func__);
> + return -ENODEV;
> + }
> +
> + hyn_reset_proc(client, 40);
> +
> + return 0;
> +}
> +
> +static void cst3xx_touch_update(struct hynitron_ts_data *ts_data,
> + s32 id, s32 x, s32 y, s32 w)
> +{
> + input_mt_slot(ts_data->input_dev, id);
> + input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, 1);
> + touchscreen_report_pos(ts_data->input_dev, &ts_data->prop, x, y, true);
> + input_report_abs(ts_data->input_dev, ABS_MT_TOUCH_MAJOR, w);
> +}
> +
> +static int cst3xx_finish_touch_read(struct i2c_client *client)
> +{
> + unsigned char buf[3];
> + int err;
> +
> + put_unaligned_le24(CST3XX_TOUCH_DATA_STOP_CMD, buf);
> + err = cst3xx_i2c_write(client, buf, 3);
> + if (err < 0) {
> + dev_err(&client->dev, "send read touch info ending failed.\n");
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Handle events from IRQ. Note that for cst3xx it appears that IRQ
> + * fires continuously while touched, otherwise once every 1500ms
> + * when not touched (assume touchscreen waking up periodically).
> + * Note buffer is sized for 5 fingers, if more needed buffer must
> + * be increased. The buffer contains 5 bytes for each touch point,
> + * a touch count byte, a check byte, and then a second check byte after
> + * all other touch points.
> + *
> + * For example 1 touch would look like this:
> + * touch1[5]:touch_count[1]:chk_byte[1]
> + *
> + * 3 touches would look like this:
> + * touch1[5]:touch_count[1]:chk_byte[1]:touch2[5]:touch3[5]:chk_byte[1]
> + */
> +static void cst3xx_touch_report(struct i2c_client *client)
> +{
> + struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
> + unsigned char buf[28];
> + unsigned char finger_id, sw;
> + unsigned int input_x = 0;
> + unsigned int input_y = 0;
> + unsigned int input_w = 0;
> + int idx = 0;
> + int i, err;
> + int touch_cnt, end_byte;
> +
> + /* Read and validate the first bits of input data. */
> + err = cst3xx_i2c_read_register(client, CST3XX_TOUCH_DATA_PART_REG,
> + buf, 28);
> + if ((err < 0) || (buf[6] != CST3XX_TOUCH_DATA_CHK_VAL) ||
> + (buf[0] == CST3XX_TOUCH_DATA_CHK_VAL)) {
> + dev_err(&client->dev, "cst3xx touch read failure\n");
> + return;
> + }
> +
> + /* Report to the device we're done reading the touch data. */
> + err = cst3xx_finish_touch_read(client);
> + if (err < 0) {
> + dev_err(&client->dev, "cst3xx touch read failure\n");
We are already printing in cst3xx_finish_touch_read(), no need to print
here again.
> + return;
> + }
> +
> + touch_cnt = buf[5] & CST3XX_TOUCH_COUNT_MASK;
> +
> + /* If no touches registered, clear the input slots. */
> + if (touch_cnt == 0) {
> + input_mt_sync_frame(ts_data->input_dev);
> + input_sync(ts_data->input_dev);
> + return;
> + }
> +
> + /*
> + * Check the check bit of the last touch slot. The check bit is
> + * always present after touch point 1 for valid data, and then
> + * appears as the last byte after all other touch data.
> + */
> + if (touch_cnt > 1) {
> + end_byte = touch_cnt * 5 + 2;
> + if (buf[end_byte] != CST3XX_TOUCH_DATA_CHK_VAL) {
> + dev_err(&client->dev, "cst3xx touch read failure\n");
> + return;
> + }
> + }
> +
> + /* Parse through the buffer to capture touch data. */
> + for (i = 0; i < touch_cnt; i++) {
> + input_x = ((buf[idx + 1] << 4) | ((buf[idx + 3] >> 4) & 0x0f));
> + input_y = ((buf[idx + 2] << 4) | (buf[idx + 3] & 0x0f));
> + input_w = (buf[idx + 4] >> 3);
> + sw = (buf[idx] & 0x0f) >> 1;
> + finger_id = (buf[idx] >> 4) & 0x0f;
> +
> + /* Sanity check we don't have more fingers than we expect */
> + if (ts_data->pdata->max_touch_num < finger_id) {
> + dev_err(&client->dev, "cst3xx touch read failure\n");
> + break;
> + }
> +
> + /* sw value of 0 means no touch, 0x03 means touch */
> + if (sw == CST3XX_TOUCH_DATA_TOUCH_VAL)
> + cst3xx_touch_update(ts_data, finger_id,
> + input_x, input_y, input_w);
> +
> + idx += 5;
> +
> + /* Skip the 2 bits between point 1 and point 2 */
> + if (i == 0)
> + idx += 2;
> + }
> +
> + input_mt_sync_frame(ts_data->input_dev);
> + input_sync(ts_data->input_dev);
> +}
> +
> +static int cst3xx_input_dev_int(struct i2c_client *client)
> +{
> + struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
> + int err;
> +
> + ts_data->input_dev = devm_input_allocate_device(&ts_data->client->dev);
> + if (!ts_data->input_dev) {
> + dev_err(&ts_data->client->dev,
> + "Failed to allocate input device.\n");
> + return -ENOMEM;
> + }
> +
> + ts_data->input_dev->name = "Hynitron cst3xx Touchscreen";
> + ts_data->input_dev->phys = "input/ts";
> + ts_data->input_dev->id.bustype = BUS_I2C;
> +
> + input_set_drvdata(ts_data->input_dev, ts_data);
> +
> + input_set_capability(ts_data->input_dev, EV_ABS, ABS_MT_POSITION_X);
> + input_set_capability(ts_data->input_dev, EV_ABS, ABS_MT_POSITION_Y);
> + input_set_abs_params(ts_data->input_dev, ABS_MT_TOUCH_MAJOR,
> + 0, 255, 0, 0);
> +
> + touchscreen_parse_properties(ts_data->input_dev, true, &ts_data->prop);
> +
> + if (!ts_data->prop.max_x || !ts_data->prop.max_y) {
> + dev_err(&client->dev,
> + "Invalid x/y (%d, %d), using defaults\n",
> + ts_data->prop.max_x, ts_data->prop.max_y);
> + ts_data->prop.max_x = 1152;
> + ts_data->prop.max_y = 1920;
> + input_abs_set_max(ts_data->input_dev,
> + ABS_MT_POSITION_X, ts_data->prop.max_x);
> + input_abs_set_max(ts_data->input_dev,
> + ABS_MT_POSITION_Y, ts_data->prop.max_y);
> + }
> +
> + err = input_mt_init_slots(ts_data->input_dev,
> + ts_data->pdata->max_touch_num,
> + INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
> + if (err < 0) {
> + dev_err(&ts_data->client->dev,
> + "Input device registration failed\n");
> + return err;
> + }
> +
> + err = input_register_device(ts_data->input_dev);
> + if (err < 0) {
> + dev_err(&ts_data->client->dev,
> + "Input device registration failed\n");
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static int hyn_probe(struct i2c_client *client)
> +{
> + struct hynitron_ts_data *ts_data;
> + int err;
> +
> + ts_data = devm_kzalloc(&client->dev, sizeof(*ts_data), GFP_KERNEL);
> + if (!ts_data)
> + return -ENOMEM;
> +
> + ts_data->client = client;
> + i2c_set_clientdata(client, ts_data);
> +
> + ts_data->reset_gpio = devm_gpiod_get(&client->dev,
> + "reset", GPIOD_OUT_LOW);
> + err = PTR_ERR_OR_ZERO(ts_data->reset_gpio);
> + if (err < 0) {
> + dev_err(&client->dev, "request reset gpio failed: %d\n", err);
> + return err;
> + }
> +
> + ts_data->pdata = of_device_get_match_data(&client->dev);
> + if (!ts_data->pdata)
> + return -EINVAL;
> +
> + hyn_reset_proc(client, 60);
> +
> + err = ts_data->pdata->bootloader_enter(client);
> + if (err < 0)
> + return err;
> +
> + err = ts_data->pdata->init_input(client);
> + if (err < 0)
> + return err;
> +
> + err = ts_data->pdata->firmware_info(client);
> + if (err < 0)
> + return err;
> +
> + err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> + hyn_interrupt_handler,
> + IRQF_ONESHOT,
> + "Hynitron Touch Int", client);
> + if (err < 0) {
> + dev_err(&client->dev, "failed to request IRQ\n");
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static const struct hynitron_ts_chip_data cst3xx_data = {
> + .max_touch_num = 5,
> + .ic_chkcode = 0xcaca0000,
> + .firmware_info = &cst3xx_firmware_info,
> + .bootloader_enter = &cst3xx_bootloader_enter,
> + .init_input = &cst3xx_input_dev_int,
> + .report_touch = &cst3xx_touch_report,
> +};
> +
> +static const struct i2c_device_id hyn_tpd_id[] = {
> + { .name = "hynitron_ts", 0 },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(i2c, hyn_tpd_id);
> +
> +static const struct of_device_id hyn_dt_match[] = {
> + { .compatible = "hynitron,cst340", .data = &cst3xx_data },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, hyn_dt_match);
> +
> +static struct i2c_driver hynitron_i2c_driver = {
> + .driver = {
> + .name = "Hynitron-TS",
> + .of_match_table = of_match_ptr(hyn_dt_match),
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> + .id_table = hyn_tpd_id,
> + .probe_new = hyn_probe,
> +};
> +
> +module_i2c_driver(hynitron_i2c_driver);
> +
> +MODULE_AUTHOR("Chris Morgan");
> +MODULE_DESCRIPTION("Hynitron Touchscreen Driver");
> +MODULE_LICENSE("GPL");
> --
> 2.25.1
