From e90f875419967589d75d1a3e2b89c5f2720e794e Mon Sep 17 00:00:00 2001
From: Matthias Kaehlcke <matthias.list@kaehlcke.net>
Date: Mon, 23 Sep 2013 22:43:29 +0200
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 <matthias@kaehlcke.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 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 baaf5a8123bb..a3685d6ef674 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 4befdb85dd9c..7b68a061cd60 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -151,6 +151,7 @@ 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;
-- 
2.20.1