Hi Chris,
On Fri, Oct 28, 2022 at 03:26:36PM -0500, Chris Morgan 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 | 505 ++++++++++++++++++++
> 3 files changed, 518 insertions(+)
> create mode 100644 drivers/input/touchscreen/hynitron_cstxxx.c
>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index dc90a3ea51ee..46b158c04c7b 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
> + 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..ca39e8a775b7
> --- /dev/null
> +++ b/drivers/input/touchscreen/hynitron_cstxxx.c
> @@ -0,0 +1,505 @@
> +// 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>
For the future: "asm" goes after "linux".
> +#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>
> +
> +/* 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;
I do not believe irq_gpio is used so I'll drop it.
> +};
> +
> +/*
> + * 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);
ARRAY_SIZE() instead of 2 is better here.
> + 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);
> +
> + 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;
I do not think we should be overriding errors returned by
cst3xx_i2c_write() and friends.
I'll update on my end, no need to resubmit.
Thanks.
--
Dmitry
