Mark,
Could you take a look at this for me please:
On Mon, 08 Mar 2021, Andreas Kemnade wrote:
> Add the version of the EC in the Tolino Shine 2 HD
> to the supported versions. It seems not to have an RTC
> and does not ack data written to it.
> The vendor kernel happily ignores write errors, using
> I2C via userspace i2c-set also shows the error.
> So add a quirk to ignore that error.
>
> PWM can be successfully configured despite of that error.
>
> Signed-off-by: Andreas Kemnade <andr...@kemnade.info>
> ---
> Changes in v2:
> - more comments about stacking regmap construction
> - fix accidential line removal
> - better naming for subdevices
>
> drivers/mfd/ntxec.c | 61 +++++++++++++++++++++++++++++++++++++--
> include/linux/mfd/ntxec.h | 1 +
> 2 files changed, 59 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mfd/ntxec.c b/drivers/mfd/ntxec.c
> index 957de2b03529..0bbd2e34e89c 100644
> --- a/drivers/mfd/ntxec.c
> +++ b/drivers/mfd/ntxec.c
> @@ -96,6 +96,38 @@ static struct notifier_block ntxec_restart_handler = {
> .priority = 128,
> };
>
> +static int regmap_ignore_write(void *context,
> + unsigned int reg, unsigned int val)
> +
> +{
> + struct regmap *regmap = context;
> +
> + regmap_write(regmap, reg, val);
> +
> + return 0;
> +}
> +
> +static int regmap_wrap_read(void *context, unsigned int reg,
> + unsigned int *val)
> +{
> + struct regmap *regmap = context;
> +
> + return regmap_read(regmap, reg, val);
> +}
> +
> +/*
> + * Some firmware versions do not ack written data, add a wrapper. It
> + * is used to stack another regmap on top.
> + */
> +static const struct regmap_config regmap_config_noack = {
> + .name = "ntxec_noack",
> + .reg_bits = 8,
> + .val_bits = 16,
> + .cache_type = REGCACHE_NONE,
> + .reg_write = regmap_ignore_write,
> + .reg_read = regmap_wrap_read
> +};
> +
> static const struct regmap_config regmap_config = {
> .name = "ntxec",
> .reg_bits = 8,
> @@ -104,15 +136,20 @@ static const struct regmap_config regmap_config = {
> .val_format_endian = REGMAP_ENDIAN_BIG,
> };
>
> -static const struct mfd_cell ntxec_subdevices[] = {
> +static const struct mfd_cell ntxec_subdev[] = {
> { .name = "ntxec-rtc" },
> { .name = "ntxec-pwm" },
> };
>
> +static const struct mfd_cell ntxec_subdev_pwm[] = {
> + { .name = "ntxec-pwm" },
> +};
> +
> static int ntxec_probe(struct i2c_client *client)
> {
> struct ntxec *ec;
> unsigned int version;
> + bool has_rtc;
> int res;
>
> ec = devm_kmalloc(&client->dev, sizeof(*ec), GFP_KERNEL);
> @@ -137,6 +174,16 @@ static int ntxec_probe(struct i2c_client *client)
> /* Bail out if we encounter an unknown firmware version */
> switch (version) {
> case NTXEC_VERSION_KOBO_AURA:
> + has_rtc = true;
> + break;
> + case NTXEC_VERSION_TOLINO_SHINE2:
> + has_rtc = false;
> + /* Another regmap stacked on top of the other */
> + ec->regmap = devm_regmap_init(ec->dev, NULL,
> + ec->regmap,
> + ®map_config_noack);
> + if (IS_ERR(ec->regmap))
> + return PTR_ERR(ec->regmap);
> break;
> default:
> dev_err(ec->dev,
> @@ -181,8 +228,16 @@ static int ntxec_probe(struct i2c_client *client)
>
> i2c_set_clientdata(client, ec);
>
> - res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE,
> ntxec_subdevices,
> - ARRAY_SIZE(ntxec_subdevices), NULL, 0, NULL);
> + if (has_rtc)
> + res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE,
> + ntxec_subdev,
> + ARRAY_SIZE(ntxec_subdev),
> + NULL, 0, NULL);
> + else
> + res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE,
> + ntxec_subdev_pwm,
> + ARRAY_SIZE(ntxec_subdev_pwm),
> + NULL, 0, NULL);
> if (res)
> dev_err(ec->dev, "Failed to add subdevices: %d\n", res);
>
> diff --git a/include/linux/mfd/ntxec.h b/include/linux/mfd/ntxec.h
> index 361204d125f1..26ab3b8eb612 100644
> --- a/include/linux/mfd/ntxec.h
> +++ b/include/linux/mfd/ntxec.h
> @@ -33,5 +33,6 @@ static inline __be16 ntxec_reg8(u8 value)
>
> /* Known firmware versions */
> #define NTXEC_VERSION_KOBO_AURA 0xd726 /* found in Kobo Aura */
> +#define NTXEC_VERSION_TOLINO_SHINE2 0xf110 /* found in Tolino Shine 2 HD */
>
> #endif
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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