Hi, (Cc'ing Mark Brown because of the regmap related questions)
On Sat, Mar 06, 2021 at 07:13:14PM +0100, 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.
I'm curious, is this one of the variants with two PWM channels
(for configurable color temperature)?
>
> Signed-off-by: Andreas Kemnade <andr...@kemnade.info>
> ---
> drivers/mfd/ntxec.c | 57 ++++++++++++++++++++++++++++++++++++---
> include/linux/mfd/ntxec.h | 1 +
> 2 files changed, 55 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mfd/ntxec.c b/drivers/mfd/ntxec.c
> index 957de2b03529..e7fe570127af 100644
> --- a/drivers/mfd/ntxec.c
> +++ b/drivers/mfd/ntxec.c
> @@ -96,6 +96,36 @@ 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 */
> +static const struct regmap_config regmap_config_noack = {
> + .name = "ntxec_noack",
> + .reg_bits = 8,
> + .val_bits = 16,
> + .cache_type = REGCACHE_NONE,
> + .val_format_endian = REGMAP_ENDIAN_BIG,
> + .reg_write = regmap_ignore_write,
> + .reg_read = regmap_wrap_read
Is the read wrapper necessary? It seems to me from reading regmap.h
that leaving .reg_read set to NULL should do the right thing, but I'm
not sure.
> +};
> +
> static const struct regmap_config regmap_config = {
> .name = "ntxec",
> .reg_bits = 8,
> @@ -109,10 +139,15 @@ static const struct mfd_cell ntxec_subdevices[] = {
> { .name = "ntxec-pwm" },
> };
>
> +static const struct mfd_cell ntxec_subdev_pwm[] = {
> + { .name = "ntxec-pwm" },
> +};
ntxec_subdevices vs. ntxec_subdev_pwm seems slightly inconsistent in
naming. ntxec_subdevices_pwm would be a wrong plural, but IMHO slightly
better because of consistency. Maybe rename ntxec_subdevices to
ntxec_subdev?
> +
> 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 +172,15 @@ 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;
> + ec->regmap = devm_regmap_init(ec->dev, NULL,
> + ec->regmap,
> + ®map_config_noack);
Ah— A custom regmap stacked on top of the old regmap… I think this
deserves a comment.
> + if (IS_ERR(ec->regmap))
> + return PTR_ERR(ec->regmap);
> break;
> default:
> dev_err(ec->dev,
> @@ -155,7 +199,6 @@ static int ntxec_probe(struct i2c_client *client)
> */
> res = regmap_write(ec->regmap, NTXEC_REG_POWERKEEP,
> NTXEC_POWERKEEP_VALUE);
> - if (res < 0)
> return res;
This deletion looks like a mistake.
>
> if (poweroff_restart_client)
> @@ -181,8 +224,16 @@ 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_subdevices,
> + ARRAY_SIZE(ntxec_subdevices),
> + 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);
At some point, it will probably be simpler to have
struct mfd_cell *subdev = ntxec_subdevices;
size_t subdev_size = ARRAY_SIZE(ntxec_subdevices);
on top of the probe function and override them in the switch statement,
but at this point I think it doesn't matter, and either way is fine.
> 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
> --
> 2.29.2
>
Thanks for your patch,
Jonathan
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