Re: [PATCH v2 1/4] Input: Add driver for Cypress Generation 5 touchscreen

Alistair Francis
2021-12-01T12:29:17Z

On Sat, Nov 6, 2021 at 4:47 PM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
>
> Hi Alistair,
>
> On Wed, Nov 03, 2021 at 09:48:27PM +1000, Alistair Francis wrote:
> > From: Mylčne Josserand <mylene.josserand@bootlin.com>
> >
...
> > +
> > +/*
> > + * For what understood in the datasheet, the register does not
> > + * matter. For consistency, used the Input Register address
> > + * but it does mean anything to the device. The important data
> > + * to send is the I2C address
> > + */
> > +static int cyttsp5_read(struct cyttsp5 *ts, u8 *buf, u32 max)
> > +{
> > + int rc;
>
> Please call this "error". Also elsewhere, variables that hold either
> error code or success (0) should be called "error".
>
> > + u32 size;
> > + u8 temp[2];
> > +
> > + if (!buf)
> > + return -EINVAL;
>
> This is an internal function. How can it be called with NULL buffer?

I have removed the check

>
> > +
> > + /* Read the frame to retrieve the size */
> > + rc = regmap_bulk_read(ts->regmap, HID_INPUT_REG, temp, 2);
>
> sizeof(temp)
>
> > + if (rc < 0)
>
> regmap_bulk_read() retirns 0 on success, so the check should be
>
> if (error)
>
> > + return rc;
> > +
> > + size = get_unaligned_le16(temp);
> > + if (!size || size == 2)
> > + return 0;
> > +
> > + if (size > max)
> > + return -EINVAL;
> > +
> > + /* Get the real value */
> > + return regmap_bulk_read(ts->regmap, HID_INPUT_REG, buf, size);
> > +}
> > +
> > +static int cyttsp5_write(struct cyttsp5 *ts, unsigned int reg, u8 *data,
> > + size_t size)
> > +{
> > + u8 cmd[HID_OUTPUT_MAX_CMD_SIZE];
> > +
> > + if (size + 1 > HID_OUTPUT_MAX_CMD_SIZE) {
> > + return -ENOMEM;
>
> Maybe -E2BIG or -EINVAL.
>
> > + }
>
> Unnecessary curly braces.
>
> > +
> > + /* High bytes of register address needed as first byte of cmd */
> > + cmd[0] = HI_BYTE(reg);
> > +
> > + /* Copy the rest of the data */
> > + if (data)
> > + memcpy(&cmd[1], data, size);
> > +
> > + /* The hardware wants to receive a frame with the address register
> > + * contains in the first two bytes. As the regmap_write function
> > + * add the register adresse in the frame, we use the LOW_BYTE as
> > + * first frame byte for the address register and the first
> > + * data byte is the high register + left of the cmd to send
> > + */
> > + return regmap_bulk_write(ts->regmap, LOW_BYTE(reg), cmd, size + 1);
> > +}
> > +
> > +static void cyttsp5_final_sync(struct input_dev *input, int max_slots,
> > + unsigned long *ids)
> > +{
> > + int t;
> > +
> > + for (t = 0; t < max_slots; t++) {
> > + if (test_bit(t, ids))
> > + continue;
> > + input_mt_slot(input, t);
> > + input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
> > + }
> > +
> > + input_sync(input);
> > +}
> > +
> > +static void cyttsp5_report_slot_liftoff(struct cyttsp5 *ts, int max_slots)
> > +{
> > + int t;
> > +
> > + if (ts->num_prv_rec == 0)
> > + return;
> > +
> > + for (t = 0; t < max_slots; t++) {
> > + input_mt_slot(ts->input, t);
> > + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, false);
> > + }
> > +}
> > +
> > +static void cyttsp5_mt_lift_all(struct cyttsp5 *ts)
> > +{
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + int max = si->tch_abs[CY_TCH_T].max;
> > +
> > + if (ts->num_prv_rec != 0) {
> > + cyttsp5_report_slot_liftoff(ts, max);
> > + input_sync(ts->input);
> > + ts->num_prv_rec = 0;
> > + }
> > +}
> > +
> > +static void cyttsp5_get_touch_axis(int *axis, int size, int max, u8 *xy_data,
> > + int bofs)
> > +{
> > + int nbyte;
> > +
> > + for (nbyte = 0, *axis = 0; nbyte < size; nbyte++)
> > + *axis = *axis + ((xy_data[nbyte] >> bofs) << (nbyte * 8));
> > +
> > + *axis &= max - 1;
>
> Can it be that max is not power of 2?

Not that I have seen.

>
> > +}
> > +
> > +static void cyttsp5_get_touch_record(struct cyttsp5 *ts,
> > + struct cyttsp5_touch *touch, u8 *xy_data)
> > +{
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + enum cyttsp5_tch_abs abs;
> > +
> > + for (abs = CY_TCH_X; abs < CY_TCH_NUM_ABS; abs++) {
> > + cyttsp5_get_touch_axis(&touch->abs[abs],
> > + si->tch_abs[abs].size,
> > + si->tch_abs[abs].max,
> > + xy_data + si->tch_abs[abs].ofs,
> > + si->tch_abs[abs].bofs);
> > + }
>
> Unnecessary curly braces.
>
> > +}
> > +
> > +static void cyttsp5_get_mt_touches(struct cyttsp5 *ts,
> > + struct cyttsp5_touch *tch, int num_cur_tch)
> > +{
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + int i, t = 0;
> > + DECLARE_BITMAP(ids, MAX_CY_TCH_T_IDS);
> > + u8 *tch_addr;
> > + int tmp;
> > +
> > + bitmap_zero(ids, MAX_CY_TCH_T_IDS);
> > + memset(tch->abs, 0, sizeof(tch->abs));
> > +
> > + for (i = 0; i < num_cur_tch; i++) {
> > + tch_addr = si->xy_data + (i * TOUCH_REPORT_SIZE);
> > + cyttsp5_get_touch_record(ts, tch, tch_addr);
> > +
> > + /* Convert MAJOR/MINOR from mm to resolution */
> > + tmp = tch->abs[CY_TCH_MAJ] * 100 * si->sensing_conf_data.res_x;
> > + tch->abs[CY_TCH_MAJ] = tmp / si->sensing_conf_data.len_x;
> > + tmp = tch->abs[CY_TCH_MIN] * 100 * si->sensing_conf_data.res_x;
> > + tch->abs[CY_TCH_MIN] = tmp / si->sensing_conf_data.len_x;
> > +
> > + t = tch->abs[CY_TCH_T];
> > + input_mt_slot(ts->input, t);
> > + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
> > + __set_bit(t, ids);
> > +
> > + /* position and pressure fields */
> > + input_report_abs(ts->input, ABS_MT_POSITION_X,
> > + tch->abs[CY_TCH_X]);
> > + input_report_abs(ts->input, ABS_MT_POSITION_Y,
> > + tch->abs[CY_TCH_Y]);
> > + input_report_abs(ts->input, ABS_MT_PRESSURE,
> > + tch->abs[CY_TCH_P]);
> > +
> > + /* Get the extended touch fields */
> > + input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
> > + tch->abs[CY_TCH_MAJ]);
> > + input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
> > + tch->abs[CY_TCH_MIN]);
> > +
> > + touchscreen_report_pos(ts->input, &ts->prop,
> > + tch->abs[CY_TCH_X], tch->abs[CY_TCH_Y],
> > + true);
>
> I have no idea why you first report position manually (without applying
> transformation) and then finally use touchscreen_report_pos() to report
> is again, now properly.

Fixed!

>
> > + }
> > +
> > + cyttsp5_final_sync(ts->input, si->tch_abs[CY_TCH_T].max, ids);
>
> I think if you use INPUT_MT_DROP_UNUSED when initializing slots and call
> input_mt_sync_frame() then cyttsp5_final_sync() will not be needed.

Yep, I have removed cyttsp5_final_sync()

>
> > +
> > + ts->num_prv_rec = num_cur_tch;
> > +}
> > +
> > +/* read xy_data for all current touches */
> > +static int cyttsp5_xy_worker(struct cyttsp5 *ts)
> > +{
> > + struct device *dev = ts->dev;
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + int max_tch = si->sensing_conf_data.max_tch;
> > + struct cyttsp5_touch tch;
> > + u8 num_cur_tch;
> > +
> > + cyttsp5_get_touch_axis(&tch.hdr, si->tch_hdr.size,
>
> I am struggling to understand why this member is called "hdr" and why it
> is a part of cyttsp5_touch.

Good point, removed.

>
> > + si->tch_hdr.max,
> > + si->xy_mode + 3 + si->tch_hdr.ofs,
> > + si->tch_hdr.bofs);
> > +
> > + num_cur_tch = tch.hdr;
> > + if (num_cur_tch > max_tch) {
> > + dev_err(dev, "Num touch err detected (n=%d)\n", num_cur_tch);
> > + num_cur_tch = max_tch;
> > + }
> > +
> > + if (num_cur_tch == 0 && ts->num_prv_rec == 0)
> > + return 0;
> > +
> > + /* extract xy_data for all currently reported touches */
> > + if (num_cur_tch)
> > + cyttsp5_get_mt_touches(ts, &tch, num_cur_tch);
> > + else
> > + cyttsp5_mt_lift_all(ts);
>
> Not needed with INPUT_MT_DROP_UNUSED.

I tried INPUT_MT_DROP_UNUSED and I still need this function

>
> > +
> > + return 0;
> > +}
> > +
> > +static int cyttsp5_mt_attention(struct device *dev)
> > +{
> > + struct cyttsp5 *ts = dev_get_drvdata(dev);
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + int rc;
> > +
> > + if (si->xy_mode[2] != HID_TOUCH_REPORT_ID)
> > + return 0;
>
> It is only ever called with this condition, why do we need to check
> this again?

Removed.

>
> > +
> > + /* core handles handshake */
> > + rc = cyttsp5_xy_worker(ts);
> > + if (rc < 0)
> > + dev_err(dev, "xy_worker error r=%d\n", rc);
> > +
> > + return rc;
> > +}
> > +
> > +static int cyttsp5_setup_input_device(struct device *dev)
> > +{
> > + struct cyttsp5 *ts = dev_get_drvdata(dev);
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + int max_x, max_y, max_p;
> > + int max_x_tmp, max_y_tmp;
> > + int rc;
> > +
> > + __set_bit(EV_ABS, ts->input->evbit);
>
> input_set_abs_params() does this I believe.

Removed

>
> > + __set_bit(EV_REL, ts->input->evbit);
>
> I do not believe the driver emits any EV_REL events.

If I delete this my userspace program doesn't start.

>
> > + __set_bit(EV_KEY, ts->input->evbit);
>
> I think I saw it done elsewhere already.

Yep, removed.

>
> > +
> > + max_x_tmp = si->sensing_conf_data.res_x;
> > + max_y_tmp = si->sensing_conf_data.res_y;
> > + max_x = max_x_tmp - 1;
> > + max_y = max_y_tmp - 1;
> > + max_p = si->sensing_conf_data.max_z;
> > +
> > + input_mt_init_slots(ts->input, si->tch_abs[CY_TCH_T].max, 0);
>
> Error handling. You also want to use INPUT_MT_POINTER and potentially
> INPUT_MT_DROP_UNUSED.

Done!

>
> > +
> > + __set_bit(ABS_MT_POSITION_X, ts->input->absbit);
> > + __set_bit(ABS_MT_POSITION_Y, ts->input->absbit);
> > + __set_bit(ABS_MT_PRESSURE, ts->input->absbit);
>
> These 3 are not needed.
>
> > +
> > + input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
> > + input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
> > + input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, max_p, 0, 0);
> > +
> > + input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
> > + input_set_abs_params(ts->input, ABS_MT_TOUCH_MINOR, 0, MAX_AREA, 0, 0);
> > +
> > + rc = input_register_device(ts->input);
> > + if (rc < 0)
> > + dev_err(dev, "Error, failed register input device r=%d\n", rc);
> > +
> > + return rc;
> > +}
> > +
> > +#ifdef CONFIG_OF
> > +static int cyttsp5_parse_dt_key_code(struct device *dev)
> > +{
> > + struct cyttsp5 *ts = dev_get_drvdata(dev);
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + struct device_node *np;
> > + int i;
> > +
> > + np = dev->of_node;
> > + if (!np)
> > + return -EINVAL;
> > +
> > + if (!si->num_btns)
> > + return 0;
> > +
> > + /* Initialize the button to RESERVED */
> > + for (i = 0; i < si->num_btns; i++)
> > + si->key_code[i] = KEY_RESERVED;
> > +
> > + return of_property_read_u32_array(np, "linux,keycodes",
> > + si->key_code, si->num_btns);
>
> I would use device_property_read_u32_array() instead and did not make it
> limited to OF.
>
> > +}
> > +#else
> > +static int cyttsp5_parse_dt_key_code(struct device *dev)
> > +{
> > + struct cyttsp5 *ts = dev_get_drvdata(dev);
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + int i;
> > +
> > + if (!si->num_btns)
> > + return 0;
> > +
> > + /* Initialize the button to RESERVED */
> > + for (i = 0; i < si->num_btns; i++)
> > + si->key_code[i] = KEY_RESERVED;
> > +
> > + return 0;
> > +}
> > +#endif
> > +
> > +static int cyttsp5_btn_attention(struct device *dev)
> > +{
> > + struct cyttsp5 *ts = dev_get_drvdata(dev);
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + int cur_btn;
> > + int cur_btn_state;
> > +
> > + if (si->xy_mode[2] != HID_BTN_REPORT_ID || !si->num_btns)
> > + return 0;
> > +
> > + /* extract button press/release touch information */
> > + for (cur_btn = 0; cur_btn < si->num_btns; cur_btn++) {
> > + /* Get current button state */
> > + cur_btn_state = (si->xy_data[0] >> (cur_btn * CY_BITS_PER_BTN))
> > + & CY_NUM_BTN_EVENT_ID;
> > +
> > + input_report_key(ts->input, si->key_code[cur_btn],
> > + cur_btn_state);
> > + input_sync(ts->input);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static u16 cyttsp5_compute_crc(u8 *buf, u32 size)
> > +{
> > + u16 remainder = 0xFFFF;
> > + u16 xor_mask = 0x0000;
> > + u32 index;
> > + u32 byte_value;
> > + u32 table_index;
> > + u32 crc_bit_width = sizeof(u16) * 8;
> > +
> > + /* Divide the message by polynomial, via the table. */
> > + for (index = 0; index < size; index++) {
> > + byte_value = buf[index];
> > + table_index = ((byte_value >> 4) & 0x0F)
> > + ^ (remainder >> (crc_bit_width - 4));
> > + remainder = crc_itu_t_table[table_index]
> > + ^ (remainder << 4);
> > + table_index = (byte_value & 0x0F)
> > + ^ (remainder >> (crc_bit_width - 4));
> > + remainder = crc_itu_t_table[table_index]
> > + ^ (remainder << 4);
> > + }
> > +
> > + /* Perform the final remainder CRC. */
> > + return remainder ^ xor_mask;
>
> Do we have matching implementation in lib/crc* by any chance?

Yep, it seems that we do.

>
> > +}
> > +
> > +static int cyttsp5_validate_cmd_response(struct cyttsp5 *ts, u8 code)
> > +{
> > + u16 size, crc;
> > + u8 status, offset;
> > + int command_code;
> > +
> > + size = get_unaligned_le16(&ts->response_buf[0]);
> > +
> > + if (!size)
> > + return 0;
> > +
> > + offset = ts->response_buf[HID_OUTPUT_RESPONSE_REPORT_OFFSET];
>
> This is definitely not an "offset".
>
> > +
> > + if (offset == HID_BL_RESPONSE_REPORT_ID) {
>
> switch (report_id) {
>
> > + if (ts->response_buf[4] != HID_OUTPUT_BL_SOP) {
> > + dev_err(ts->dev, "HID output response, wrong SOP\n");
> > + return -EPROTO;
> > + }
> > +
> > + if (ts->response_buf[size - 1] != HID_OUTPUT_BL_EOP) {
> > + dev_err(ts->dev, "HID output response, wrong EOP\n");
> > + return -EPROTO;
> > + }
> > +
> > + crc = cyttsp5_compute_crc(&ts->response_buf[4], size - 7);
> > + if (ts->response_buf[size - 3] != LOW_BYTE(crc) ||
> > + ts->response_buf[size - 2] != HI_BYTE(crc)) {
> > + dev_err(ts->dev, "HID output response, wrong CRC 0x%X\n",
> > + crc);
> > + return -EPROTO;
> > + }
> > +
> > + status = ts->response_buf[5];
> > + if (status) {
> > + dev_err(ts->dev, "HID output response, ERROR:%d\n",
> > + status);
> > + return -EPROTO;
> > + }
> > + }
> > +
> > + if (offset == HID_APP_RESPONSE_REPORT_ID) {
> > + command_code = ts->response_buf[HID_OUTPUT_RESPONSE_CMD_OFFSET]
> > + & HID_OUTPUT_RESPONSE_CMD_MASK;
> > + if (command_code != code) {
> > + dev_err(ts->dev,
> > + "HID output response, wrong command_code:%X\n",
> > + command_code);
> > + return -EPROTO;
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static void cyttsp5_si_get_btn_data(struct cyttsp5 *ts)
> > +{
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > + int i;
> > + unsigned int btns = ts->response_buf[HID_SYSINFO_BTN_OFFSET]
> > + & HID_SYSINFO_BTN_MASK;
> > +
> > + si->num_btns = 0;
> > + for (i = 0; i < HID_SYSINFO_MAX_BTN; i++) {
> > + if (btns & BIT(i))
> > + si->num_btns++;
> > + }
>
> hweight*()?

Fixed!

>
> > +}
> > +
> > +static int cyttsp5_get_sysinfo_regs(struct cyttsp5 *ts)
> > +{
> > + struct cyttsp5_sensing_conf_data *scd = &ts->sysinfo.sensing_conf_data;
> > + struct cyttsp5_sensing_conf_data_dev *scd_dev =
> > + (struct cyttsp5_sensing_conf_data_dev *)
> > + &ts->response_buf[HID_SYSINFO_SENSING_OFFSET];
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > +
> > + cyttsp5_si_get_btn_data(ts);
> > +
> > + scd->max_tch = scd_dev->max_num_of_tch_per_refresh_cycle;
> > + scd->res_x = get_unaligned_le16(&scd_dev->res_x);
> > + scd->res_y = get_unaligned_le16(&scd_dev->res_y);
> > + scd->max_z = get_unaligned_le16(&scd_dev->max_z);
> > + scd->len_x = get_unaligned_le16(&scd_dev->len_x);
> > + scd->len_y = get_unaligned_le16(&scd_dev->len_y);
> > +
> > + si->xy_data = devm_kzalloc(ts->dev, scd->max_tch * TOUCH_REPORT_SIZE,
> > + GFP_KERNEL);
>
> What it the absolute maximum for tracked contacts? I wonder if it makes
> sense to allocate this buffer separately.

I have removed this as well and just use the input_buf.

>
> > + if (!si->xy_data)
> > + return -ENOMEM;
> > +
> > + si->xy_mode = devm_kzalloc(ts->dev, TOUCH_INPUT_HEADER_SIZE,
> > + GFP_KERNEL);
> > + if (!si->xy_mode)
> > + return -ENOMEM;
>
> Why do we need to allocate 7 bytes separately?

I have removed this.

>
> > +
> > + return 0;
> > +}
> > +
...
> > +
> > +static int move_touch_data(struct cyttsp5 *ts, struct cyttsp5_sysinfo *si)
> > +{
> > + int max_tch = si->sensing_conf_data.max_tch;
> > + int num_cur_tch;
> > + int length;
> > + struct cyttsp5_tch_abs_params *tch = &si->tch_hdr;
> > +
> > + memcpy(si->xy_mode, ts->input_buf, TOUCH_INPUT_HEADER_SIZE);
> > +
> > + cyttsp5_get_touch_axis(&num_cur_tch, tch->size,
> > + tch->max, si->xy_mode + 3 + tch->ofs, tch->bofs);
> > + if (unlikely(num_cur_tch > max_tch))
> > + num_cur_tch = max_tch;
> > +
> > + length = num_cur_tch * TOUCH_REPORT_SIZE;
> > +
> > + memcpy(si->xy_data, &ts->input_buf[TOUCH_INPUT_HEADER_SIZE], length);
>
> Why do we need to do all these moves? Can we parse the date directly
> from the input buffer?

We don't need the moves. I have removed them.

>
> > +
> > + return 0;
> > +}
> > +
> > +static irqreturn_t cyttsp5_handle_irq(int irq, void *handle)
> > +{
> > + struct cyttsp5 *ts = handle;
> > + int report_id;
> > + int size;
> > + int rc;
> > +
> > + rc = cyttsp5_read(ts, ts->input_buf, CY_MAX_INPUT);
> > + if (rc)
> > + return IRQ_HANDLED;
> > +
> > + size = get_unaligned_le16(&ts->input_buf[0]);
> > +
> > + /* check reset */
> > + if (size == 0) {
> > + memcpy(ts->response_buf, ts->input_buf, 2);
> > +
> > + mutex_lock(&ts->system_lock);
>
> Why is this lock needed exactly?

I don't think it is, I have removed it.

>
> > + ts->hid_cmd_state = HID_CMD_DONE;
> > + mutex_unlock(&ts->system_lock);
> > + wake_up(&ts->wait_q);
> > + return IRQ_HANDLED;
> > + }
> > +
> > + report_id = ts->input_buf[2];
>
> I'd probably do:
>
> if (size == 0) {
> /* reset */
> report_id = HID_EMPTY_RESPONSE_ID; /* = 0 */
> size = 2;
> } else {
> report_id = ts->input_buf[2];
> }
>
> > +
> > + if (report_id == HID_TOUCH_REPORT_ID) {
>
> switch (report_id) {

Good idea, fixed.

>
> > + move_touch_data(ts, &ts->sysinfo);
> > + cyttsp5_mt_attention(ts->dev);
> > + } else if (report_id == HID_BTN_REPORT_ID) {
> > + move_button_data(ts, &ts->sysinfo);
> > + cyttsp5_btn_attention(ts->dev);
> > + } else {
> > + /* It is not an input but a command response */
> > + memcpy(ts->response_buf, ts->input_buf, size);
> > +
> > + mutex_lock(&ts->system_lock);
> > + ts->hid_cmd_state = HID_CMD_DONE;
> > + mutex_unlock(&ts->system_lock);
> > + wake_up(&ts->wait_q);
> > + }
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int cyttsp5_deassert_int(struct cyttsp5 *ts)
> > +{
> > + u16 size;
> > + u8 buf[2];
> > + int rc;
> > +
> > + rc = regmap_bulk_read(ts->regmap, HID_INPUT_REG, buf, 2);
> > + if (rc < 0)
> > + return rc;
> > +
> > + size = get_unaligned_le16(&buf[0]);
> > + if (size == 2 || size == 0)
> > + return 0;
>
> If you were to use level interrupts this probably would not be needed.

I have tried with/without this and I still can't get level interrupts working.

>
> > +
> > + return -EINVAL;
> > +}
> > +
> > +static int cyttsp5_fill_all_touch(struct cyttsp5 *ts)
> > +{
> > + struct cyttsp5_sysinfo *si = &ts->sysinfo;
> > +
> > + fill_tch_abs(&si->tch_abs[CY_TCH_X], REPORT_SIZE_16,
> > + TOUCH_REPORT_DESC_X);
> > + fill_tch_abs(&si->tch_abs[CY_TCH_Y], REPORT_SIZE_16,
> > + TOUCH_REPORT_DESC_Y);
> > + fill_tch_abs(&si->tch_abs[CY_TCH_P], REPORT_SIZE_8,
> > + TOUCH_REPORT_DESC_P);
> > + fill_tch_abs(&si->tch_abs[CY_TCH_T], REPORT_SIZE_5,
> > + TOUCH_REPORT_DESC_CONTACTID);
> > + fill_tch_abs(&si->tch_hdr, REPORT_SIZE_5,
> > + TOUCH_REPORT_DESC_HDR_CONTACTCOUNT);
> > + fill_tch_abs(&si->tch_abs[CY_TCH_MAJ], REPORT_SIZE_8,
> > + TOUCH_REPORT_DESC_MAJ);
> > + fill_tch_abs(&si->tch_abs[CY_TCH_MIN], REPORT_SIZE_8,
> > + TOUCH_REPORT_DESC_MIN);
> > +
> > + return 0;
> > +}
> > +
> > +static int cyttsp5_startup(struct cyttsp5 *ts)
> > +{
> > + int rc;
> > +
> > + rc = cyttsp5_deassert_int(ts);
> > + if (rc) {
> > + dev_err(ts->dev, "Error on deassert int r=%d\n", rc);
> > + return -ENODEV;
> > + }
> > +
> > + /*
> > + * Launch the application as the device starts in bootloader mode
> > + * because of a power-on-reset
> > + */
> > + rc = cyttsp5_hid_output_bl_launch_app(ts);
> > + if (rc < 0) {
> > + dev_err(ts->dev, "Error on launch app r=%d\n", rc);
> > + return rc;
> > + }
> > +
> > + rc = cyttsp5_get_hid_descriptor(ts, &ts->hid_desc);
> > + if (rc < 0) {
> > + dev_err(ts->dev, "Error on getting HID descriptor r=%d\n", rc);
> > + return rc;
> > + }
> > +
> > + rc = cyttsp5_fill_all_touch(ts);
> > + if (rc < 0) {
> > + dev_err(ts->dev, "Error on report descriptor r=%d\n", rc);
> > + return rc;
> > + }
> > +
> > + rc = cyttsp5_hid_output_get_sysinfo(ts);
> > + if (rc) {
> > + dev_err(ts->dev, "Error on getting sysinfo r=%d\n", rc);
> > + return rc;
> > + }
> > +
> > + return rc;
> > +}
> > +
> > +#ifdef CONFIG_OF
> > +static const struct of_device_id cyttsp5_of_match[] = {
> > + { .compatible = "cypress,tt21000", },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(of, cyttsp5_of_match);
> > +#endif
> > +
> > +static const struct i2c_device_id cyttsp5_i2c_id[] = {
> > + { CYTTSP5_NAME, 0, },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, cyttsp5_i2c_id);
> > +
> > +static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq,
> > + const char *name)
> > +{
> > + struct cyttsp5 *ts;
> > + struct cyttsp5_sysinfo *si;
> > + int rc = 0, i;
> > +
> > + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> > + if (!ts)
> > + return -ENOMEM;
> > +
> > + /* Initialize device info */
> > + ts->regmap = regmap;
> > + ts->dev = dev;
> > + si = &ts->sysinfo;
> > + dev_set_drvdata(dev, ts);
> > +
> > + /* Initialize mutexes and spinlocks */
> > + mutex_init(&ts->system_lock);
> > +
> > + /* Initialize wait queue */
> > + init_waitqueue_head(&ts->wait_q);
> > +
> > + /* Power up the device */
> > + ts->vdd = regulator_get(dev, "vdd");
>
> Do not mix managed an unmanaged resources. You are leaking this
> regulator.

I'm not clear what I should do differently here.

>
> > + if (IS_ERR(ts->vdd)) {
> > + rc = PTR_ERR(ts->vdd);
> > + dev_set_drvdata(dev, NULL);
> > + kfree(ts);
> > + return rc;
> > + }
> > +
> > + rc = regulator_enable(ts->vdd);
> > + if (rc) {
> > + regulator_put(ts->vdd);
> > + dev_set_drvdata(dev, NULL);
> > + kfree(ts);
> > + return rc;
> > + }
> > +
> > + /* Reset the gpio to be in a reset state */
> > + ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> > + if (IS_ERR(ts->reset_gpio)) {
> > + rc = PTR_ERR(ts->reset_gpio);
> > + dev_err(dev, "Failed to request reset gpio, error %d\n", rc);
> > + return rc;
> > + }
> > + gpiod_set_value(ts->reset_gpio, 1);
> > +
> > + /* Need a delay to have device up */
> > + msleep(20);
> > +
> > + rc = devm_request_threaded_irq(dev, irq, NULL, cyttsp5_handle_irq,
> > + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
>
> Please do not override platform setup with hardcoded triggers. Also, it
> is strongly recommended to use level interrupts for these peripherals.
>
> This is also likely unsafe if controller is not completely shut off and
> is capable of generating interrupts given input device is not yet
> allocated.

I have dropped the `IRQF_TRIGGER_FALLING |`

I have tried to use level interrupts, but I can't get the device
working with them.

>
> > + name, ts);
> > + if (rc) {
> > + dev_err(dev, "unable to request IRQ\n");
> > + return rc;
> > + }
> > +
> > + rc = cyttsp5_startup(ts);
> > + if (rc) {
> > + dev_err(ts->dev, "Fail initial startup r=%d\n", rc);
> > + return rc;
> > + }
> > +
> > + rc = cyttsp5_parse_dt_key_code(dev);
> > + if (rc < 0) {
> > + dev_err(ts->dev, "Error while parsing dts %d\n", rc);
> > + return rc;
> > + }
> > +
> > + ts->input = devm_input_allocate_device(dev);
> > + if (!ts->input) {
> > + dev_err(dev, "Error, failed to allocate input device\n");
> > + return -ENODEV;
> > + }
> > +
> > + ts->input->name = "cyttsp5";
> > + scnprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
> > + ts->input->phys = ts->phys;
> > + ts->input->dev.parent = ts->dev;
>
> No need to do this, devm_input_allocate_device() sets up parent.
>
> > + input_set_drvdata(ts->input, ts);
> > +
> > + touchscreen_parse_properties(ts->input, true, &ts->prop);
> > +
> > + __set_bit(EV_KEY, ts->input->evbit);
> > + __set_bit(ABS_X, ts->input->absbit);
> > + __set_bit(ABS_Y, ts->input->absbit);
> > + __set_bit(BTN_TOUCH, ts->input->keybit);
>
> These 3 should not be needed.
>
> > + for (i = 0; i < si->num_btns; i++)
> > + __set_bit(si->key_code[i], ts->input->keybit);
> > +
> > + return cyttsp5_setup_input_device(dev);
> > +}
> > +
> > +static int cyttsp5_i2c_probe(struct i2c_client *client,
> > + const struct i2c_device_id *id)
> > +{
> > + struct regmap *regmap;
> > + static const struct regmap_config config = {
> > + .reg_bits = 8,
> > + .val_bits = 8,
> > + };
> > +
> > + regmap = devm_regmap_init_i2c(client, &config);
> > + if (IS_ERR(regmap)) {
> > + dev_err(&client->dev, "regmap allocation failed: %ld\n",
> > + PTR_ERR(regmap));
> > + return PTR_ERR(regmap);
> > + }
> > +
> > + return cyttsp5_probe(&client->dev, regmap, client->irq, client->name);
> > +}
> > +
> > +static int cyttsp5_remove(struct device *dev)
> > +{
> > + struct cyttsp5 *ts = dev_get_drvdata(dev);
> > +
> > + input_unregister_device(ts->input);
>
> This is not needed as input device is devm managed. This entire function
> can be dropped.

Removed

>
> > +
> > + return 0;
> > +}
> > +
> > +static int cyttsp5_i2c_remove(struct i2c_client *client)
> > +{
> > + struct device *dev = &client->dev;
> > +
> > + return cyttsp5_remove(dev);
> > +}
> > +
> > +static struct i2c_driver cyttsp5_i2c_driver = {
> > + .driver = {
> > + .name = CYTTSP5_NAME,
> > + .of_match_table = of_match_ptr(cyttsp5_of_match),
> > + },
> > + .probe = cyttsp5_i2c_probe,
> > + .remove = cyttsp5_i2c_remove,
> > + .id_table = cyttsp5_i2c_id,
> > +};
> > +
> > +module_i2c_driver(cyttsp5_i2c_driver);
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("Touchscreen driver for Cypress TrueTouch Gen 5 Product");
> > +MODULE_AUTHOR("Mylčne Josserand <mylene.josserand@bootlin.com>");
> > --
> > 2.31.1
> >
>
> Thanks.

Thanks for the in depth review.

I have addressed all of the issues that I didn't comment on.

Alistair

>
> --
> Dmitry