Re: [PATCH v6 4/4] Input: Add TouchNetix aXiom I2C Touchscreen support

[Andrew Thomas <andrew.thomas@touchnetix.com>]

On Fri, Mar 13, 2026 at 08:50:05PM +0100, Marco Felsch wrote:
>Hi Andrew,
>
>thanks for your feedback! Please see below.
>
>On 26-03-13, Andrew Thomas wrote:
>> On Tue, Mar 03, 2026 at 11:41:22PM +0100, Marco Felsch wrote:
>> >This adds the initial support for the TouchNetix AX54A touchcontroller
>> >which is part of TouchNetix's aXiom touchscreen controller family.
>> >
>> >The TouchNetix aXiom family provides two physical interfaces: SPI and
>> >I2C. This patch covers only the I2C interface.
>> >
>> >Apart the input event handling the driver supports firmware updates too.
>> >One firmware interface handles the touchcontroller firmware (AXFW)
>> >update the other handles the touchcontroller configuration (TH2CFGBIN)
>> >update.
>> >
>> >Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
>> >---
>
>...
>
>> >+static int axiom_u02_enter_bootloader(struct axiom_data *ts)
>> >+{
>> >+	struct axiom_u02_rev1_system_manager_msg msg = { };
>> >+	struct device *dev = ts->dev;
>> >+	unsigned int val;
>> >+	int error;
>> >+
>> >+	if (!axiom_driver_supports_usage(ts, AXIOM_U02))
>> >+		return -EINVAL;
>> >+
>> >+	/*
>> >+	 * Enter the bootloader mode requires 3 consecutive messages so we can't
>> >+	 * check for the response.
>> >+	 * TODO: Check if it's required to add a delay between the consecutive
>> >+	 * CMD_ENTERBOOTLOADER cmds.
>> >+	 */
>> >+	msg.command = cpu_to_le16(AXIOM_U02_REV1_CMD_ENTERBOOTLOADER);
>> >+	msg.parameters[0] = cpu_to_le16(AXIOM_U02_REV1_PARAM0_ENTERBOOLOADER_KEY1);
>> >+	error = axiom_u02_send_msg(ts, &msg, false);
>>
>> As mentioned before the delay between commands is too short and the
>> next command is sent before u02 is ready, which means the driver fails
>> to put axiom into the bootloader.
>
>Please see my comment [1].
>
>> Have you tested with an i2c speed of 400KHz?
>
>Yes, my target platform is based on a i.MX8MP.
>
>> All you need is to put true in above to wait for the bootloader command.
>> error = axiom_u02_send_msg(ts, &msg, true);
>
>Please see my comment [1].
>
>> Just dont do it for the last command.
>
>Please see my comment [1].
>
>> I am not too sure why you are having issues with this, this is how we
>> do it for all our devices.
>
>Please see my comment [1].
>
>On what platform do you perform the tests?
>
>> >+	if (error) {
>> >+		dev_err(dev, "Failed to send bootloader-key1: %d\n", error);
>> >+		return error;
>> >+	}
>> >+
>> >+	msg.parameters[0] = cpu_to_le16(AXIOM_U02_REV1_PARAM0_ENTERBOOLOADER_KEY2);
>> >+	error = axiom_u02_send_msg(ts, &msg, false);
>>
>> Here also.
>
>Please see my comment [1].
>
>> >+	if (error) {
>> >+		dev_err(dev, "Failed to send bootloader-key2: %d\n", error);
>> >+		return error;
>> >+	}
>> >+
>> >+	msg.parameters[0] = cpu_to_le16(AXIOM_U02_REV1_PARAM0_ENTERBOOLOADER_KEY3);
>> >+	error = axiom_u02_send_msg(ts, &msg, false);
>> >+	if (error) {
>> >+		dev_err(dev, "Failed to send bootloader-key3: %d\n", error);
>> >+		return error;
>> >+	}
>> >+
>> >+	/* Sleep before the first read to give the device time */
>> >+	fsleep(250 * USEC_PER_MSEC);
>> >+
>> >+	/* Wait till the device reports it is in bootloader mode */
>> >+	error = regmap_read_poll_timeout(ts->regmap,
>> >+					 AXIOM_U31_REV1_DEVICE_ID_HIGH_REG, val,
>> >+					 FIELD_GET(AXIOM_U31_REV1_MODE_MASK, val) ==
>> >+						AXIOM_U31_REV1_MODE_BLP,
>> >+					 250 * USEC_PER_MSEC, USEC_PER_SEC);
>> >+	if (error)
>> >+		return error;
>> >+
>> >+	return 0;
>> >+}
>> >+
>>
>> ...
>>
>>
>> Other than the above comments I have no issues with the driver.
>
>If you're fine with the patch you could add your acked-by [2] :)
>
>> We can support more usages in a later patch.
>
>Sure :)
>
>[1] https://lore.kernel.org/all/4x3dnedfzf3rqzsy3wjdoj6yaxmy6kop37xhxeao4vjer7ifdi@35ux42ztq3eb
>[2] https://docs.kernel.org/process/submitting-patches.html#when-to-use-acked-by-cc-and-co-developed-by
>
>Regards,
>  Marco
>-- 
>#gernperDu
>#CallMeByMyFirstName
>
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Acked-by: Andrew Thomas <andrew.thomas@touchnetix.com>