lkml.org 
[lkml]   [2017]   [Oct]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: hwmon: da9052 Increase sample rate when using TSI
On Thu, Oct 19, 2017 at 04:51:44PM +0100, Martyn Welch wrote:
> The TSI channel, which is usually used for touchscreen support, but can
> be used as 4 general purpose ADCs. When used as a touchscreen interface
> the touchscreen driver switches the device into 1ms sampling mode (rather
> than the default 10ms economy mode) as recommended by the manufacturer.
> When using the TSI channels as a general purpose ADC we are currently not
> doing this and testing suggests that this can result in ADC timeouts:
>
> [ 5827.198289] da9052 spi2.0: timeout waiting for ADC conversion interrupt
> [ 5827.728293] da9052 spi2.0: timeout waiting for ADC conversion interrupt
> [ 5993.808335] da9052 spi2.0: timeout waiting for ADC conversion interrupt
> [ 5994.328441] da9052 spi2.0: timeout waiting for ADC conversion interrupt
> [ 5994.848291] da9052 spi2.0: timeout waiting for ADC conversion interrupt
>
> Switching to the 1ms timing resolves this issue.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
> Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>

Applied; replaced Cc: stable@ with Fixes:

> ---
> drivers/hwmon/da9052-hwmon.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/hwmon/da9052-hwmon.c b/drivers/hwmon/da9052-hwmon.c
> index 97a62f5..a973eb6 100644
> --- a/drivers/hwmon/da9052-hwmon.c
> +++ b/drivers/hwmon/da9052-hwmon.c
> @@ -477,6 +477,11 @@ static int da9052_hwmon_probe(struct platform_device *pdev)
> /* disable touchscreen features */
> da9052_reg_write(hwmon->da9052, DA9052_TSI_CONT_A_REG, 0x00);
>
> + /* Sample every 1ms */
> + da9052_reg_update(hwmon->da9052, DA9052_ADC_CONT_REG,
> + DA9052_ADCCONT_ADCMODE,
> + DA9052_ADCCONT_ADCMODE);
> +
> err = da9052_request_irq(hwmon->da9052, DA9052_IRQ_TSIREADY,
> "tsiready-irq", da9052_tsi_datardy_irq,
> hwmon);

\
 
 \ /
  Last update: 2017-10-22 17:50    [W:0.047 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site