[PATCH] mfd: ti_am335x_tscadc: Update logic in CTRL register for 5-wire TS

From: Sebastian Andrzej Siewior
Date: Thu Sep 04 2014 - 13:02:18 EST


From: Jeff Lance <j-lance1@xxxxxx>

The logic in AFE_Pen_Ctrl bitmask in the CTRL register is different for five
wire versus four or eight wire touschscreens. This patch should fix this for
five-wire touch screens. There should be no change needed here for four and
eight wire tousch screens.

Signed-off-by: Jeff Lance <j-lance1@xxxxxx>
[bigeasy: keep the change mfd only]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
I've been looking at moving this piece and the idle mode setting into the
TSC driver. Kinda odd that I have to patch within the MFD driver for this
TSC related change.
Anyone disagrees?

drivers/mfd/ti_am335x_tscadc.c | 30 +++++++++++++++++-------------
include/linux/mfd/ti_am335x_tscadc.h | 1 +
2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index dd4bf5816221..6c9cfb8c1d01 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -241,18 +241,20 @@ static int ti_tscadc_probe(struct platform_device *pdev)
tscadc_writel(tscadc, REG_CLKDIV, tscadc->clk_div);

/* Set the control register bits */
- ctrl = CNTRLREG_STEPCONFIGWRT |
- CNTRLREG_STEPID;
- if (tsc_wires > 0)
- ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
+ ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
tscadc_writel(tscadc, REG_CTRL, ctrl);

/* Set register bits for Idle Config Mode */
- if (tsc_wires > 0)
+ if (tsc_wires > 0) {
+ tscadc->tsc_wires = tsc_wires;
+ if (tsc_wires == 5)
+ ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
+ else
+ ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
tscadc_idle_config(tscadc);
+ }

/* Enable the TSC module enable bit */
- ctrl = tscadc_readl(tscadc, REG_CTRL);
ctrl |= CNTRLREG_TSCSSENB;
tscadc_writel(tscadc, REG_CTRL, ctrl);

@@ -324,21 +326,23 @@ static int tscadc_suspend(struct device *dev)
static int tscadc_resume(struct device *dev)
{
struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);
- unsigned int restore, ctrl;
+ u32 ctrl;

pm_runtime_get_sync(dev);

/* context restore */
ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
- if (tscadc_dev->tsc_cell != -1)
- ctrl |= CNTRLREG_TSCENB | CNTRLREG_4WIRE;
tscadc_writel(tscadc_dev, REG_CTRL, ctrl);

- if (tscadc_dev->tsc_cell != -1)
+ if (tscadc_dev->tsc_cell != -1) {
+ if (tscadc_dev->tsc_wires == 5)
+ ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
+ else
+ ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
tscadc_idle_config(tscadc_dev);
- restore = tscadc_readl(tscadc_dev, REG_CTRL);
- tscadc_writel(tscadc_dev, REG_CTRL,
- (restore | CNTRLREG_TSCSSENB));
+ }
+ ctrl |= CNTRLREG_TSCSSENB;
+ tscadc_writel(tscadc_dev, REG_CTRL, ctrl);

tscadc_writel(tscadc_dev, REG_CLKDIV, tscadc_dev->clk_div);

diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index fb96c84dada5..e2e70053470e 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -155,6 +155,7 @@ struct ti_tscadc_dev {
void __iomem *tscadc_base;
int irq;
int used_cells; /* 1-2 */
+ int tsc_wires;
int tsc_cell; /* -1 if not used */
int adc_cell; /* -1 if not used */
struct mfd_cell cells[TSCADC_CELLS];
--
2.1.0

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