On Sun, 15 Sep 2019 20:53:42 +0200
Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> Since commit 9bcf15f75cac ("iio: adc: axp288: Fix TS-pin handling") we
> preserve the bias current set by the firmware at boot. This fixes issues
> we were seeing on various models, but it seems our old hardcoded 80ųA bias
> current was working around a firmware bug on at least one model laptop.
>
> In order to both have our cake and eat it, this commit adds a dmi based
> list of models where we need to override the firmware set bias current and
> adds the one model we now know needs this to it: The Lenovo Ideapad 100S
> (11 inch version).
Ouch.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 9bcf15f75cac ("iio: adc: axp288: Fix TS-pin handling")
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=203829
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Applied to the fixes-togreg branch of iio.git.
Thanks,
Jonathan
> ---
> drivers/iio/adc/axp288_adc.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/drivers/iio/adc/axp288_adc.c b/drivers/iio/adc/axp288_adc.c
> index 31d51bcc5f2c..85d08e68b34f 100644
> --- a/drivers/iio/adc/axp288_adc.c
> +++ b/drivers/iio/adc/axp288_adc.c
> @@ -7,6 +7,7 @@
> * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> */
>
> +#include <linux/dmi.h>
> #include <linux/module.h>
> #include <linux/kernel.h>
> #include <linux/device.h>
> @@ -25,6 +26,11 @@
> #define AXP288_ADC_EN_MASK 0xF0
> #define AXP288_ADC_TS_ENABLE 0x01
>
> +#define AXP288_ADC_TS_BIAS_MASK GENMASK(5, 4)
> +#define AXP288_ADC_TS_BIAS_20UA (0 << 4)
> +#define AXP288_ADC_TS_BIAS_40UA (1 << 4)
> +#define AXP288_ADC_TS_BIAS_60UA (2 << 4)
> +#define AXP288_ADC_TS_BIAS_80UA (3 << 4)
> #define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0)
> #define AXP288_ADC_TS_CURRENT_OFF (0 << 0)
> #define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0)
> @@ -177,10 +183,36 @@ static int axp288_adc_read_raw(struct iio_dev *indio_dev,
> return ret;
> }
>
> +/*
> + * We rely on the machine's firmware to correctly setup the TS pin bias current
> + * at boot. This lists systems with broken fw where we need to set it ourselves.
> + */
> +static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
> + {
> + /* Lenovo Ideapad 100S (11 inch) */
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
> + },
> + .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
> + },
> + {}
> +};
> +
> static int axp288_adc_initialize(struct axp288_adc_info *info)
> {
> + const struct dmi_system_id *bias_override;
> int ret, adc_enable_val;
>
> + bias_override = dmi_first_match(axp288_adc_ts_bias_override);
> + if (bias_override) {
> + ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
> + AXP288_ADC_TS_BIAS_MASK,
> + (uintptr_t)bias_override->driver_data);
> + if (ret)
> + return ret;
> + }
> +
> /*
> * Determine if the TS pin is enabled and set the TS current-source
> * accordingly.
