2013-09-23 20:43:38

by Matthias Kaehlcke

Subject: [PATCH] mfd: ti_am335x_tscadc: Restore clock divider on resume

The ADC clock divider needs to be restored on resume as the register content
is lost when the ADC is powered down

Signed-off-by: Matthias Kaehlcke <[email protected]>

---
drivers/mfd/ti_am335x_tscadc.c | 10 ++++++----
include/linux/mfd/ti_am335x_tscadc.h | 1 +
2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index baaf5a8..a3685d6 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -95,7 +95,7 @@ static int ti_tscadc_probe(struct platform_device *pdev)
const __be32 *cur;
u32 val;
int err, ctrl;
- int clk_value, clock_rate;
+ int clock_rate;
int tsc_wires = 0, adc_channels = 0, total_channels;
int readouts = 0;

@@ -196,11 +196,11 @@ static int ti_tscadc_probe(struct platform_device *pdev)
}
clock_rate = clk_get_rate(clk);
clk_put(clk);
- clk_value = clock_rate / ADC_CLK;
+ tscadc->clk_div = clock_rate / ADC_CLK;

/* TSCADC_CLKDIV needs to be configured to the value minus 1 */
- clk_value = clk_value - 1;
- tscadc_writel(tscadc, REG_CLKDIV, clk_value);
+ tscadc->clk_div--;
+ tscadc_writel(tscadc, REG_CLKDIV, tscadc->clk_div);

/* Set the control register bits */
ctrl = CNTRLREG_STEPCONFIGWRT |
@@ -303,6 +303,8 @@ static int tscadc_resume(struct device *dev)
tscadc_writel(tscadc_dev, REG_CTRL,
(restore | CNTRLREG_TSCSSENB));

+ tscadc_writel(tscadc_dev, REG_CLKDIV, tscadc_dev->clk_div);
+
return 0;
}

diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 25f2c61..f03281d 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -146,6 +146,7 @@ struct ti_tscadc_dev {
struct mfd_cell cells[TSCADC_CELLS];
u32 reg_se_cache;
spinlock_t reg_lock;
+ unsigned int clk_div;

/* tsc device */
struct titsc *tsc;
--
1.7.9.5

2013-09-27 08:23:15

by Lee Jones

Subject: Re: [PATCH] mfd: ti_am335x_tscadc: Restore clock divider on resume

On Mon, 23 Sep 2013, Matthias Kaehlcke wrote:

> The ADC clock divider needs to be restored on resume as the register content
> is lost when the ADC is powered down
>
> Signed-off-by: Matthias Kaehlcke <[email protected]>
>
> ---
> drivers/mfd/ti_am335x_tscadc.c | 10 ++++++----
> include/linux/mfd/ti_am335x_tscadc.h | 1 +
> 2 files changed, 7 insertions(+), 4 deletions(-)

I would question why 'struct ti_tscadc_dev' has different names
throughout the driver, but that has nothing to do with this patch.

Applied, thanks.

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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