2012-08-30 07:56:00

by Patil, Rachna

[permalink] [raw]
Subject: [PATCH v2 0/5] Support for TSC/ADC MFD driver

This patch set adds a MFD core driver which registers
touchscreen and ADC as its client drivers.
The existing touchscreen has been modified to work as
a MFD client driver and a new ADC driver has been added
in the IIO subsystem.

There are 8 analog input lines, which can be used as:
1. 8 general purpose ADC channels
2. 4 wire TS, with 4 general purpose ADC channels
3. 5 wire TS, with 3 general purpose ADC channels

This patch set has been tested on AM335x EVM.

These set of patches are based on top of Touchscreen patch
set submitted.
Subject: [PATCH 0/4] input: TSC: ti_tscadc: TI Touchscreen driver updates [1]

[1] http://www.spinics.net/lists/linux-input/msg22107.html

Changes in v2:
Dropped one patch send in the last version after
receiving internal comments. I have merged the changes
into existing patches.
Also added a new patch to support suspend/resume feature.
Fixed review comments by Matthias Kaehlcke.

Patil, Rachna (5):
input: TSC: ti_tscadc: Rename the existing touchscreen driver
MFD: ti_tscadc: Add support for TI's TSC/ADC MFDevice
input: TSC: ti_tsc: Convert TSC into a MFDevice
IIO : ADC: tiadc: Add support of TI's ADC driver
MFD: ti_tscadc: add suspend/resume functionality

drivers/iio/adc/Kconfig | 7 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti_adc.c | 248 ++++++++++++++++
drivers/input/touchscreen/Kconfig | 4 +-
drivers/input/touchscreen/Makefile | 2 +-
.../input/touchscreen/{ti_tscadc.c => ti_tsc.c} | 310 ++++++--------------
drivers/mfd/Kconfig | 9 +
drivers/mfd/Makefile | 1 +
drivers/mfd/ti_tscadc.c | 251 ++++++++++++++++
include/linux/input/{ti_tscadc.h => ti_tsc.h} | 4 +-
include/linux/mfd/ti_tscadc.h | 151 ++++++++++
include/linux/platform_data/ti_adc.h | 14 +
12 files changed, 774 insertions(+), 228 deletions(-)
create mode 100644 drivers/iio/adc/ti_adc.c
rename drivers/input/touchscreen/{ti_tscadc.c => ti_tsc.c} (55%)
create mode 100644 drivers/mfd/ti_tscadc.c
rename include/linux/input/{ti_tscadc.h => ti_tsc.h} (90%)
create mode 100644 include/linux/mfd/ti_tscadc.h
create mode 100644 include/linux/platform_data/ti_adc.h


2012-08-30 07:56:07

by Patil, Rachna

[permalink] [raw]
Subject: [PATCH v2 5/5] MFD: ti_tscadc: add suspend/resume functionality

This patch adds support for suspend/resume of
TSC/ADC MFDevice.

Signed-off-by: Patil, Rachna <[email protected]>
---
Changes in v2:
Added this patch newly in this patch series.

drivers/iio/adc/ti_adc.c | 32 ++++++++++++++++++++++++++++++++
drivers/input/touchscreen/ti_tsc.c | 33 +++++++++++++++++++++++++++++++++
drivers/mfd/ti_tscadc.c | 33 ++++++++++++++++++++++++++++++++-
include/linux/mfd/ti_tscadc.h | 3 +++
4 files changed, 100 insertions(+), 1 deletions(-)

diff --git a/drivers/iio/adc/ti_adc.c b/drivers/iio/adc/ti_adc.c
index d2e621c..14601f0 100644
--- a/drivers/iio/adc/ti_adc.c
+++ b/drivers/iio/adc/ti_adc.c
@@ -200,6 +200,36 @@ static int __devexit tiadc_remove(struct platform_device *pdev)
return 0;
}

+static int adc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
+ struct adc_device *adc_dev = tscadc_dev->adc;
+ unsigned int idle;
+
+ if (!device_may_wakeup(tscadc_dev->dev)) {
+ idle = adc_readl(adc_dev, REG_CTRL);
+ idle &= ~(CNTRLREG_TSCSSENB);
+ adc_writel(adc_dev, REG_CTRL, (idle |
+ CNTRLREG_POWERDOWN));
+ }
+ return 0;
+}
+
+static int adc_resume(struct platform_device *pdev)
+{
+ struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
+ struct adc_device *adc_dev = tscadc_dev->adc;
+ unsigned int restore;
+
+ /* Make sure ADC is powered up */
+ restore = adc_readl(adc_dev, REG_CTRL);
+ restore &= ~(CNTRLREG_POWERDOWN);
+ adc_writel(adc_dev, REG_CTRL, restore);
+
+ adc_step_config(adc_dev);
+ return 0;
+}
+
static struct platform_driver tiadc_driver = {
.driver = {
.name = "tiadc",
@@ -207,6 +237,8 @@ static struct platform_driver tiadc_driver = {
},
.probe = tiadc_probe,
.remove = __devexit_p(tiadc_remove),
+ .suspend = adc_suspend,
+ .resume = adc_resume,
};

module_platform_driver(tiadc_driver);
diff --git a/drivers/input/touchscreen/ti_tsc.c b/drivers/input/touchscreen/ti_tsc.c
index ca8ce73..f103e5f 100644
--- a/drivers/input/touchscreen/ti_tsc.c
+++ b/drivers/input/touchscreen/ti_tsc.c
@@ -338,6 +338,37 @@ static int __devexit tscadc_remove(struct platform_device *pdev)
return 0;
}

+static int tsc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
+ struct tscadc *ts_dev = tscadc_dev->tsc;
+ unsigned int idle;
+
+ if (device_may_wakeup(tscadc_dev->dev)) {
+ idle = tscadc_readl(ts_dev, REG_IRQENABLE);
+ tscadc_writel(ts_dev, REG_IRQENABLE,
+ (idle | IRQENB_HW_PEN));
+ tscadc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
+ }
+ return 0;
+}
+
+static int tsc_resume(struct platform_device *pdev)
+{
+ struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
+ struct tscadc *ts_dev = tscadc_dev->tsc;
+
+ if (device_may_wakeup(tscadc_dev->dev)) {
+ tscadc_writel(ts_dev, REG_IRQWAKEUP,
+ 0x00);
+ tscadc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
+ }
+ tscadc_step_config(ts_dev);
+ tscadc_writel(ts_dev, REG_FIFO0THR,
+ ts_dev->steps_to_configure);
+ return 0;
+}
+
static struct platform_driver ti_tsc_driver = {
.probe = tscadc_probe,
.remove = __devexit_p(tscadc_remove),
@@ -345,6 +376,8 @@ static struct platform_driver ti_tsc_driver = {
.name = "tsc",
.owner = THIS_MODULE,
},
+ .suspend = tsc_suspend,
+ .resume = tsc_resume,
};
module_platform_driver(ti_tsc_driver);

diff --git a/drivers/mfd/ti_tscadc.c b/drivers/mfd/ti_tscadc.c
index 9dbd6d0..2c84aed 100644
--- a/drivers/mfd/ti_tscadc.c
+++ b/drivers/mfd/ti_tscadc.c
@@ -170,6 +170,7 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
if (err < 0)
goto err_disable_clk;

+ device_init_wakeup(&pdev->dev, true);
platform_set_drvdata(pdev, tscadc);
return 0;

@@ -203,6 +204,35 @@ static int __devexit ti_tscadc_remove(struct platform_device *pdev)
return 0;
}

+static int tscadc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct ti_tscadc_dev *tscadc_dev = platform_get_drvdata(pdev);
+
+ tscadc_writel(tscadc_dev, REG_SE, 0x00);
+ pm_runtime_put_sync(&pdev->dev);
+ return 0;
+}
+
+static int tscadc_resume(struct platform_device *pdev)
+{
+ struct ti_tscadc_dev *tscadc_dev = platform_get_drvdata(pdev);
+ unsigned int restore, ctrl;
+
+ pm_runtime_get_sync(&pdev->dev);
+
+ /* context restore */
+ ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB |
+ CNTRLREG_STEPID | CNTRLREG_4WIRE;
+ tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
+ tscadc_idle_config(tscadc_dev);
+ tscadc_writel(tscadc_dev, REG_SE, STPENB_STEPENB);
+ restore = tscadc_readl(tscadc_dev, REG_CTRL);
+ tscadc_writel(tscadc_dev, REG_CTRL,
+ (restore | CNTRLREG_TSCSSENB));
+
+ return 0;
+}
+
static struct platform_driver ti_tscadc_driver = {
.driver = {
.name = "ti_tscadc",
@@ -210,7 +240,8 @@ static struct platform_driver ti_tscadc_driver = {
},
.probe = ti_tscadc_probe,
.remove = __devexit_p(ti_tscadc_remove),
-
+ .suspend = tscadc_suspend,
+ .resume = tscadc_resume,
};

module_platform_driver(ti_tscadc_driver);
diff --git a/include/linux/mfd/ti_tscadc.h b/include/linux/mfd/ti_tscadc.h
index 3414883..e0a6437 100644
--- a/include/linux/mfd/ti_tscadc.h
+++ b/include/linux/mfd/ti_tscadc.h
@@ -40,6 +40,9 @@
#define REG_FIFO1 0x200

/* Register Bitfields */
+/* IRQ wakeup enable */
+#define IRQWKUP_ENB BIT(0)
+
/* Step Enable */
#define STEPENB_MASK (0x1FFFF << 0)
#define STEPENB(val) ((val) << 0)
--
1.7.1

2012-08-30 07:56:05

by Patil, Rachna

[permalink] [raw]
Subject: [PATCH v2 3/5] input: TSC: ti_tsc: Convert TSC into a MFDevice

This patch converts touchscreen into a MFD client.
All the register definitions, clock initialization,
etc has been moved to MFD core driver.

Signed-off-by: Patil, Rachna <[email protected]>
---
Changes in v2:
No changes

drivers/input/touchscreen/ti_tsc.c | 277 +++++++-----------------------------
drivers/mfd/ti_tscadc.c | 11 ++
include/linux/mfd/ti_tscadc.h | 10 ++-
3 files changed, 74 insertions(+), 224 deletions(-)

diff --git a/drivers/input/touchscreen/ti_tsc.c b/drivers/input/touchscreen/ti_tsc.c
index 8e94c00..ca8ce73 100644
--- a/drivers/input/touchscreen/ti_tsc.c
+++ b/drivers/input/touchscreen/ti_tsc.c
@@ -26,123 +26,31 @@
#include <linux/io.h>
#include <linux/input/ti_tsc.h>
#include <linux/delay.h>
-
-#define REG_RAWIRQSTATUS 0x024
-#define REG_IRQSTATUS 0x028
-#define REG_IRQENABLE 0x02C
-#define REG_IRQWAKEUP 0x034
-#define REG_CTRL 0x040
-#define REG_ADCFSM 0x044
-#define REG_CLKDIV 0x04C
-#define REG_SE 0x054
-#define REG_IDLECONFIG 0x058
-#define REG_CHARGECONFIG 0x05C
-#define REG_CHARGEDELAY 0x060
-#define REG_STEPCONFIG(n) (0x64 + ((n - 1) * 8))
-#define REG_STEPDELAY(n) (0x68 + ((n - 1) * 8))
-#define REG_FIFO0CNT 0xE4
-#define REG_FIFO0THR 0xE8
-#define REG_FIFO1THR 0xF4
-#define REG_FIFO0 0x100
-#define REG_FIFO1 0x200
-
-/* Register Bitfields */
-#define IRQWKUP_ENB BIT(0)
-
-/* Step Enable */
-#define STEPENB_MASK (0x1FFFF << 0)
-#define STEPENB(val) (val << 0)
-#define STPENB_STEPENB STEPENB(0x7FFF)
-
-/* IRQ enable */
-#define IRQENB_FIFO0THRES BIT(2)
-#define IRQENB_FIFO1THRES BIT(5)
-#define IRQENB_PENUP BIT(9)
-
-/* Step Configuration */
-#define STEPCONFIG_MODE_MASK (3 << 0)
-#define STEPCONFIG_MODE(val) (val << 0)
-#define STEPCONFIG_MODE_HWSYNC STEPCONFIG_MODE(2)
-#define STEPCONFIG_AVG_MASK (7 << 2)
-#define STEPCONFIG_AVG(val) (val << 2)
-#define STEPCONFIG_AVG_16 STEPCONFIG_AVG(4)
-#define STEPCONFIG_XPP BIT(5)
-#define STEPCONFIG_XNN BIT(6)
-#define STEPCONFIG_YPP BIT(7)
-#define STEPCONFIG_YNN BIT(8)
-#define STEPCONFIG_XNP BIT(9)
-#define STEPCONFIG_YPN BIT(10)
-#define STEPCONFIG_INM_MASK (0xF << 15)
-#define STEPCONFIG_INM(val) (val << 15)
-#define STEPCONFIG_INM_ADCREFM STEPCONFIG_INM(8)
-#define STEPCONFIG_INP_MASK (0xF << 19)
-#define STEPCONFIG_INP(val) (val << 19)
-#define STEPCONFIG_INP_AN2 STEPCONFIG_INP(2)
-#define STEPCONFIG_INP_AN3 STEPCONFIG_INP(3)
-#define STEPCONFIG_INP_AN4 STEPCONFIG_INP(4)
-#define STEPCONFIG_INP_ADCREFM STEPCONFIG_INP(8)
-#define STEPCONFIG_FIFO1 BIT(26)
-
-/* Delay register */
-#define STEPDELAY_OPEN_MASK (0x3FFFF << 0)
-#define STEPDELAY_OPEN(val) (val << 0)
-#define STEPCONFIG_OPENDLY STEPDELAY_OPEN(0x098)
-
-/* Charge Config */
-#define STEPCHARGE_RFP_MASK (7 << 12)
-#define STEPCHARGE_RFP(val) (val << 12)
-#define STEPCHARGE_RFP_XPUL STEPCHARGE_RFP(1)
-#define STEPCHARGE_INM_MASK (0xF << 15)
-#define STEPCHARGE_INM(val) (val << 15)
-#define STEPCHARGE_INM_AN1 STEPCHARGE_INM(1)
-#define STEPCHARGE_INP_MASK (0xF << 19)
-#define STEPCHARGE_INP(val) (val << 19)
-#define STEPCHARGE_INP_AN1 STEPCHARGE_INP(1)
-#define STEPCHARGE_RFM_MASK (3 << 23)
-#define STEPCHARGE_RFM(val) (val << 23)
-#define STEPCHARGE_RFM_XNUR STEPCHARGE_RFM(1)
-
-/* Charge delay */
-#define CHARGEDLY_OPEN_MASK (0x3FFFF << 0)
-#define CHARGEDLY_OPEN(val) (val << 0)
-#define CHARGEDLY_OPENDLY CHARGEDLY_OPEN(1)
-
-/* Control register */
-#define CNTRLREG_TSCSSENB BIT(0)
-#define CNTRLREG_STEPID BIT(1)
-#define CNTRLREG_STEPCONFIGWRT BIT(2)
-#define CNTRLREG_AFE_CTRL_MASK (3 << 5)
-#define CNTRLREG_AFE_CTRL(val) (val << 5)
-#define CNTRLREG_4WIRE CNTRLREG_AFE_CTRL(1)
-#define CNTRLREG_5WIRE CNTRLREG_AFE_CTRL(2)
-#define CNTRLREG_8WIRE CNTRLREG_AFE_CTRL(3)
-#define CNTRLREG_TSCENB BIT(7)
+#include <linux/mfd/ti_tscadc.h>

#define ADCFSM_STEPID 0x10
#define SEQ_SETTLE 275
-#define ADC_CLK 3000000
#define MAX_12BIT ((1 << 12) - 1)

struct tscadc {
struct input_dev *input;
- struct clk *tsc_ick;
- void __iomem *tsc_base;
unsigned int irq;
unsigned int wires;
unsigned int x_plate_resistance;
bool pen_down;
int steps_to_configure;
+ struct ti_tscadc_dev *mfd_tscadc;
};

static unsigned int tscadc_readl(struct tscadc *ts, unsigned int reg)
{
- return readl(ts->tsc_base + reg);
+ return readl(ts->mfd_tscadc->tscadc_base + reg);
}

static void tscadc_writel(struct tscadc *tsc, unsigned int reg,
unsigned int val)
{
- writel(val, tsc->tsc_base + reg);
+ writel(val, tsc->mfd_tscadc->tscadc_base + reg);
}

static void tscadc_step_config(struct tscadc *ts_dev)
@@ -219,17 +127,7 @@ static void tscadc_step_config(struct tscadc *ts_dev)
tscadc_writel(ts_dev, REG_STEPDELAY(total_steps + 2),
STEPCONFIG_OPENDLY);

- tscadc_writel(ts_dev, REG_SE, STPENB_STEPENB);
-}
-
-static void tscadc_idle_config(struct tscadc *ts_config)
-{
- unsigned int idleconfig;
-
- idleconfig = STEPCONFIG_YNN |
- STEPCONFIG_INM_ADCREFM |
- STEPCONFIG_YPN | STEPCONFIG_INP_ADCREFM;
- tscadc_writel(ts_config, REG_IDLECONFIG, idleconfig);
+ tscadc_writel(ts_dev, REG_SE, STPENB_STEPENB_TC);
}

static void tscadc_read_coordinates(struct tscadc *ts_dev,
@@ -239,7 +137,7 @@ static void tscadc_read_coordinates(struct tscadc *ts_dev,
unsigned int prev_val_x = ~0, prev_val_y = ~0;
unsigned int prev_diff_x = ~0, prev_diff_y = ~0;
unsigned int read, diff;
- unsigned int i;
+ unsigned int i, channel;

/*
* Delta filter is used to remove large variations in sampled
@@ -250,21 +148,32 @@ static void tscadc_read_coordinates(struct tscadc *ts_dev,
* if true the value is reported to the sub system.
*/
for (i = 0; i < fifocount - 1; i++) {
- read = tscadc_readl(ts_dev, REG_FIFO0) & 0xfff;
- diff = abs(read - prev_val_x);
- if (diff < prev_diff_x) {
- prev_diff_x = diff;
- *x = read;
+ read = tscadc_readl(ts_dev, REG_FIFO0);
+ channel = read & 0xf0000;
+ channel = channel >> 0x10;
+ if ((channel >= 0) && (channel < ts_dev->steps_to_configure)) {
+ read &= 0xfff;
+ diff = abs(read - prev_val_x);
+ if (diff < prev_diff_x) {
+ prev_diff_x = diff;
+ *x = read;
+ }
+ prev_val_x = read;
}
- prev_val_x = read;

- read = tscadc_readl(ts_dev, REG_FIFO1) & 0xfff;
- diff = abs(read - prev_val_y);
- if (diff < prev_diff_y) {
- prev_diff_y = diff;
- *y = read;
- }
+ read = tscadc_readl(ts_dev, REG_FIFO1);
+ channel = read & 0xf0000;
+ channel = channel >> 0x10;
+ if ((channel >= ts_dev->steps_to_configure) &&
+ (channel < (2 * ts_dev->steps_to_configure - 1))) {
+ read &= 0xfff;
+ diff = abs(read - prev_val_y);
+ if (diff < prev_diff_y) {
+ prev_diff_y = diff;
+ *y = read;
+ }
prev_val_y = read;
+ }
}
}

@@ -276,6 +185,8 @@ static irqreturn_t tscadc_irq(int irq, void *dev)
unsigned int x = 0, y = 0;
unsigned int z1, z2, z;
unsigned int fsm;
+ unsigned int fifo1count, fifo0count;
+ int i;

status = tscadc_readl(ts_dev, REG_IRQSTATUS);
if (status & IRQENB_FIFO0THRES) {
@@ -284,6 +195,14 @@ static irqreturn_t tscadc_irq(int irq, void *dev)
z1 = tscadc_readl(ts_dev, REG_FIFO0) & 0xfff;
z2 = tscadc_readl(ts_dev, REG_FIFO1) & 0xfff;

+ fifo1count = tscadc_readl(ts_dev, REG_FIFO1CNT);
+ for (i = 0; i < fifo1count; i++)
+ tscadc_readl(ts_dev, REG_FIFO1);
+
+ fifo0count = tscadc_readl(ts_dev, REG_FIFO0CNT);
+ for (i = 0; i < fifo0count; i++)
+ tscadc_readl(ts_dev, REG_FIFO0);
+
if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
/*
* Calculate pressure using formula
@@ -340,28 +259,15 @@ static irqreturn_t tscadc_irq(int irq, void *dev)

static int __devinit tscadc_probe(struct platform_device *pdev)
{
- const struct tsc_data *pdata = pdev->dev.platform_data;
- struct resource *res;
struct tscadc *ts_dev;
struct input_dev *input_dev;
- struct clk *clk;
int err;
- int clk_value, ctrl, irq;
+ struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
+ struct mfd_tscadc_board *pdata;

+ pdata = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data;
if (!pdata) {
- dev_err(&pdev->dev, "missing platform data.\n");
- return -EINVAL;
- }
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev, "no memory resource defined.\n");
- return -EINVAL;
- }
-
- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "no irq ID is specified.\n");
+ dev_err(tscadc_dev->dev, "Could not find platform data\n");
return -EINVAL;
}

@@ -374,85 +280,26 @@ static int __devinit tscadc_probe(struct platform_device *pdev)
goto err_free_mem;
}

+ tscadc_dev->tsc = ts_dev;
+ ts_dev->mfd_tscadc = tscadc_dev;
ts_dev->input = input_dev;
- ts_dev->irq = irq;
- ts_dev->wires = pdata->wires;
- ts_dev->x_plate_resistance = pdata->x_plate_resistance;
- ts_dev->steps_to_configure = pdata->steps_to_configure;
-
- res = request_mem_region(res->start, resource_size(res), pdev->name);
- if (!res) {
- dev_err(&pdev->dev, "failed to reserve registers.\n");
- err = -EBUSY;
- goto err_free_mem;
- }
-
- ts_dev->tsc_base = ioremap(res->start, resource_size(res));
- if (!ts_dev->tsc_base) {
- dev_err(&pdev->dev, "failed to map registers.\n");
- err = -ENOMEM;
- goto err_release_mem_region;
- }
+ ts_dev->irq = tscadc_dev->irq;
+ ts_dev->wires = pdata->tsc_init->wires;
+ ts_dev->x_plate_resistance = pdata->tsc_init->x_plate_resistance;
+ ts_dev->steps_to_configure = pdata->tsc_init->steps_to_configure;

err = request_irq(ts_dev->irq, tscadc_irq,
0, pdev->dev.driver->name, ts_dev);
if (err) {
dev_err(&pdev->dev, "failed to allocate irq.\n");
- goto err_unmap_regs;
- }
-
- ts_dev->tsc_ick = clk_get(&pdev->dev, "adc_tsc_ick");
- if (IS_ERR(ts_dev->tsc_ick)) {
- dev_err(&pdev->dev, "failed to get TSC ick\n");
- goto err_free_irq;
- }
- clk_enable(ts_dev->tsc_ick);
-
- clk = clk_get(&pdev->dev, "adc_tsc_fck");
- if (IS_ERR(clk)) {
- dev_err(&pdev->dev, "failed to get TSC fck\n");
- err = PTR_ERR(clk);
- goto err_disable_clk;
- }
-
- clk_value = clk_get_rate(clk) / ADC_CLK;
- clk_put(clk);
-
- if (clk_value < 7) {
- dev_err(&pdev->dev, "clock input less than min clock requirement\n");
- goto err_disable_clk;
- }
- /* CLKDIV needs to be configured to the value minus 1 */
- tscadc_writel(ts_dev, REG_CLKDIV, clk_value - 1);
-
- /* Enable wake-up of the SoC using touchscreen */
- tscadc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
-
- ctrl = CNTRLREG_STEPCONFIGWRT |
- CNTRLREG_TSCENB |
- CNTRLREG_STEPID;
- switch (ts_dev->wires) {
- case 4:
- ctrl |= CNTRLREG_4WIRE;
- break;
- case 5:
- ctrl |= CNTRLREG_5WIRE;
- break;
- case 8:
- ctrl |= CNTRLREG_8WIRE;
- break;
+ goto err_free_mem;
}
- tscadc_writel(ts_dev, REG_CTRL, ctrl);

- tscadc_idle_config(ts_dev);
tscadc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
tscadc_step_config(ts_dev);
tscadc_writel(ts_dev, REG_FIFO0THR, ts_dev->steps_to_configure);

- ctrl |= CNTRLREG_TSCSSENB;
- tscadc_writel(ts_dev, REG_CTRL, ctrl);
-
- input_dev->name = "ti-tsc-adc";
+ input_dev->name = "ti-tsc";
input_dev->dev.parent = &pdev->dev;

input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
@@ -465,20 +312,13 @@ static int __devinit tscadc_probe(struct platform_device *pdev)
/* register to the input system */
err = input_register_device(input_dev);
if (err)
- goto err_disable_clk;
+ goto err_free_irq;

platform_set_drvdata(pdev, ts_dev);
return 0;

-err_disable_clk:
- clk_disable(ts_dev->tsc_ick);
- clk_put(ts_dev->tsc_ick);
err_free_irq:
free_irq(ts_dev->irq, ts_dev);
-err_unmap_regs:
- iounmap(ts_dev->tsc_base);
-err_release_mem_region:
- release_mem_region(res->start, resource_size(res));
err_free_mem:
input_free_device(input_dev);
kfree(ts_dev);
@@ -487,22 +327,13 @@ err_free_mem:

static int __devexit tscadc_remove(struct platform_device *pdev)
{
- struct tscadc *ts_dev = platform_get_drvdata(pdev);
- struct resource *res;
+ struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
+ struct tscadc *ts_dev = tscadc_dev->tsc;

free_irq(ts_dev->irq, ts_dev);
-
input_unregister_device(ts_dev->input);

- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- iounmap(ts_dev->tsc_base);
- release_mem_region(res->start, resource_size(res));
-
- clk_disable(ts_dev->tsc_ick);
- clk_put(ts_dev->tsc_ick);
-
kfree(ts_dev);
-
platform_set_drvdata(pdev, NULL);
return 0;
}
diff --git a/drivers/mfd/ti_tscadc.c b/drivers/mfd/ti_tscadc.c
index ac4bf7b..f26e53b 100644
--- a/drivers/mfd/ti_tscadc.c
+++ b/drivers/mfd/ti_tscadc.c
@@ -22,6 +22,7 @@
#include <linux/mfd/core.h>
#include <linux/pm_runtime.h>
#include <linux/mfd/ti_tscadc.h>
+#include <linux/input/ti_tsc.h>

static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
{
@@ -50,15 +51,19 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
struct resource *res;
struct clk *clk;
struct mfd_tscadc_board *pdata = pdev->dev.platform_data;
+ struct mfd_cell *cell;
int irq;
int err, ctrl;
int clk_value, clock_rate;
+ int tsc_wires;

if (!pdata) {
dev_err(&pdev->dev, "Could not find platform data\n");
return -EINVAL;
}

+ tsc_wires = pdata->tsc_init->wires;
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "no memory resource defined.\n");
@@ -138,6 +143,12 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
ctrl |= CNTRLREG_TSCSSENB;
tscadc_writel(tscadc, REG_CTRL, ctrl);

+ /* TSC Cell */
+ cell = &tscadc->cells[TSC_CELL];
+ cell->name = "tsc";
+ cell->platform_data = tscadc;
+ cell->pdata_size = sizeof(*tscadc);
+
err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
TSCADC_CELLS, NULL, 0);
if (err < 0)
diff --git a/include/linux/mfd/ti_tscadc.h b/include/linux/mfd/ti_tscadc.h
index a700085..de314a6 100644
--- a/include/linux/mfd/ti_tscadc.h
+++ b/include/linux/mfd/ti_tscadc.h
@@ -44,6 +44,7 @@
#define STEPENB_MASK (0x1FFFF << 0)
#define STEPENB(val) ((val) << 0)
#define STPENB_STEPENB STEPENB(0x7FFF)
+#define STPENB_STEPENB_TC STEPENB(0x1FFF)

/* IRQ enable */
#define IRQENB_HW_PEN BIT(0)
@@ -117,7 +118,11 @@
#define ADC_CLK 3000000
#define MAX_CLK_DIV 7

-#define TSCADC_CELLS 0
+#define TSCADC_CELLS 1
+
+enum tscadc_cells {
+ TSC_CELL,
+};

struct mfd_tscadc_board {
struct tsc_data *tsc_init;
@@ -128,6 +133,9 @@ struct ti_tscadc_dev {
void __iomem *tscadc_base;
int irq;
struct mfd_cell cells[TSCADC_CELLS];
+
+ /* tsc device */
+ struct tscadc *tsc;
};

#endif
--
1.7.1

2012-08-30 07:56:46

by Patil, Rachna

[permalink] [raw]
Subject: [PATCH v2 4/5] IIO : ADC: tiadc: Add support of TI's ADC driver

This patch adds support for TI's ADC driver.
This is a multifunctional device.
Analog input lines are provided on which
voltage measurements can be carried out.
You can have upto 8 input lines.

Signed-off-by: Patil, Rachna <[email protected]>
---
Changes in v2:
Addressed review comments from Matthias Kaehlcke

drivers/iio/adc/Kconfig | 7 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti_adc.c | 216 ++++++++++++++++++++++++++++++++++
drivers/mfd/ti_tscadc.c | 18 +++-
include/linux/mfd/ti_tscadc.h | 9 ++-
include/linux/platform_data/ti_adc.h | 14 ++
6 files changed, 263 insertions(+), 2 deletions(-)
create mode 100644 drivers/iio/adc/ti_adc.c
create mode 100644 include/linux/platform_data/ti_adc.h

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 8a78b4f..ad32df8 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -22,4 +22,11 @@ config AT91_ADC
help
Say yes here to build support for Atmel AT91 ADC.

+config TI_ADC
+ tristate "TI's ADC driver"
+ depends on ARCH_OMAP2PLUS
+ help
+ Say yes here to build support for Texas Instruments ADC
+ driver which is also a MFD client.
+
endmenu
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 52eec25..a930cee 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -4,3 +4,4 @@

obj-$(CONFIG_AD7266) += ad7266.o
obj-$(CONFIG_AT91_ADC) += at91_adc.o
+obj-$(CONFIG_TI_ADC) += ti_adc.o
diff --git a/drivers/iio/adc/ti_adc.c b/drivers/iio/adc/ti_adc.c
new file mode 100644
index 0000000..d2e621c
--- /dev/null
+++ b/drivers/iio/adc/ti_adc.c
@@ -0,0 +1,216 @@
+/*
+ * TI ADC MFD driver
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/iio/iio.h>
+
+#include <linux/mfd/ti_tscadc.h>
+#include <linux/platform_data/ti_adc.h>
+
+struct adc_device {
+ struct ti_tscadc_dev *mfd_tscadc;
+ struct iio_dev *idev;
+ int channels;
+};
+
+static unsigned int adc_readl(struct adc_device *adc, unsigned int reg)
+{
+ return readl(adc->mfd_tscadc->tscadc_base + reg);
+}
+
+static void adc_writel(struct adc_device *adc, unsigned int reg,
+ unsigned int val)
+{
+ writel(val, adc->mfd_tscadc->tscadc_base + reg);
+}
+
+static void adc_step_config(struct adc_device *adc_dev)
+{
+ unsigned int stepconfig;
+ int i, channels = 0, steps;
+
+ /*
+ * There are 16 configurable steps and 8 analog input
+ * lines available which are shared between Touchscreen and ADC.
+ *
+ * Steps backwards i.e. from 16 towards 0 are used by ADC
+ * depending on number of input lines needed.
+ * Channel would represent which analog input
+ * needs to be given to ADC to digitalize data.
+ */
+
+ steps = TOTAL_STEPS - adc_dev->channels;
+ channels = TOTAL_CHANNELS - adc_dev->channels;
+
+ stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1;
+
+ for (i = (steps + 1); i <= TOTAL_STEPS; i++) {
+ adc_writel(adc_dev, REG_STEPCONFIG(i),
+ stepconfig | STEPCONFIG_INP(channels));
+ adc_writel(adc_dev, REG_STEPDELAY(i),
+ STEPCONFIG_OPENDLY);
+ channels++;
+ }
+ adc_writel(adc_dev, REG_SE, STPENB_STEPENB);
+}
+
+static int tiadc_channel_init(struct iio_dev *idev, struct adc_device *adc_dev)
+{
+ struct iio_chan_spec *chan_array;
+ int i;
+
+ idev->num_channels = adc_dev->channels;
+ chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
+ GFP_KERNEL);
+
+ if (chan_array == NULL)
+ return -ENOMEM;
+
+ for (i = 0; i < (idev->num_channels); i++) {
+ struct iio_chan_spec *chan = chan_array + i;
+ chan->type = IIO_VOLTAGE;
+ chan->indexed = 1;
+ chan->channel = i;
+ chan->scan_type.sign = 'u';
+ chan->scan_type.realbits = 12;
+ chan->scan_type.storagebits = 32;
+ chan->scan_type.shift = 0;
+ }
+
+ idev->channels = chan_array;
+ return idev->num_channels;
+}
+
+static void tiadc_channel_remove(struct iio_dev *idev)
+{
+ kfree(idev->channels);
+}
+
+static int tiadc_read_raw(struct iio_dev *idev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct adc_device *adc_dev = iio_priv(idev);
+ int i;
+ unsigned int fifo1count, readx1;
+
+ fifo1count = adc_readl(adc_dev, REG_FIFO1CNT);
+ for (i = 0; i < fifo1count; i++) {
+ readx1 = adc_readl(adc_dev, REG_FIFO1);
+ if (i == chan->channel) {
+ readx1 = readx1 & 0xfff;
+ *val = readx1;
+ }
+ }
+ adc_writel(adc_dev, REG_SE, STPENB_STEPENB);
+ return IIO_VAL_INT;
+}
+
+static const struct iio_info tiadc_info = {
+ .read_raw = &tiadc_read_raw,
+};
+
+static int __devinit tiadc_probe(struct platform_device *pdev)
+{
+ struct iio_dev *idev;
+ int err;
+ struct adc_device *adc_dev = NULL;
+ struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
+ struct mfd_tscadc_board *pdata;
+
+ pdata = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data;
+ if (!pdata || !pdata->adc_init) {
+ dev_err(tscadc_dev->dev, "Could not find platform data\n");
+ return -EINVAL;
+ }
+
+ idev = iio_device_alloc(sizeof(struct adc_device));
+ if (idev == NULL) {
+ dev_err(&pdev->dev, "failed to allocate iio device.\n");
+ err = -ENOMEM;
+ goto err_allocate;
+ }
+ adc_dev = iio_priv(idev);
+
+ tscadc_dev->adc = adc_dev;
+ adc_dev->mfd_tscadc = tscadc_dev;
+ adc_dev->idev = idev;
+ adc_dev->channels = pdata->adc_init->adc_channels;
+
+ idev->dev.parent = &pdev->dev;
+ idev->name = dev_name(&pdev->dev);
+ idev->modes = INDIO_DIRECT_MODE;
+ idev->info = &tiadc_info;
+
+ adc_step_config(adc_dev);
+
+ err = tiadc_channel_init(idev, adc_dev);
+ if (err < 0)
+ goto err_cleanup_channels;
+
+ err = iio_device_register(idev);
+ if (err)
+ goto err_unregister;
+
+ dev_info(&pdev->dev, "attached adc driver\n");
+ platform_set_drvdata(pdev, idev);
+
+ return 0;
+
+err_unregister:
+ tiadc_channel_remove(idev);
+err_cleanup_channels:
+ iio_device_unregister(idev);
+ iio_device_free(idev);
+err_allocate:
+ return err;
+}
+
+static int __devexit tiadc_remove(struct platform_device *pdev)
+{
+ struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
+ struct adc_device *adc_dev = tscadc_dev->adc;
+ struct iio_dev *idev = adc_dev->idev;
+
+ iio_device_unregister(idev);
+ tiadc_channel_remove(idev);
+
+ tscadc_dev->adc = NULL;
+
+ iio_device_free(idev);
+ return 0;
+}
+
+static struct platform_driver tiadc_driver = {
+ .driver = {
+ .name = "tiadc",
+ .owner = THIS_MODULE,
+ },
+ .probe = tiadc_probe,
+ .remove = __devexit_p(tiadc_remove),
+};
+
+module_platform_driver(tiadc_driver);
+
+MODULE_DESCRIPTION("TI ADC controller driver");
+MODULE_AUTHOR("Rachna Patil <[email protected]>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/ti_tscadc.c b/drivers/mfd/ti_tscadc.c
index f26e53b..9dbd6d0 100644
--- a/drivers/mfd/ti_tscadc.c
+++ b/drivers/mfd/ti_tscadc.c
@@ -23,6 +23,7 @@
#include <linux/pm_runtime.h>
#include <linux/mfd/ti_tscadc.h>
#include <linux/input/ti_tsc.h>
+#include <linux/platform_data/ti_adc.h>

static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
{
@@ -55,14 +56,23 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
int irq;
int err, ctrl;
int clk_value, clock_rate;
- int tsc_wires;
+ int tsc_wires, adc_channels = 0, total_channels;

if (!pdata) {
dev_err(&pdev->dev, "Could not find platform data\n");
return -EINVAL;
}

+ if (pdata->adc_init)
+ adc_channels = pdata->adc_init->adc_channels;
+
tsc_wires = pdata->tsc_init->wires;
+ total_channels = tsc_wires + adc_channels;
+
+ if (total_channels > 8) {
+ dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
+ return -EINVAL;
+ }

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
@@ -149,6 +159,12 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
cell->platform_data = tscadc;
cell->pdata_size = sizeof(*tscadc);

+ /* ADC Cell */
+ cell = &tscadc->cells[ADC_CELL];
+ cell->name = "tiadc";
+ cell->platform_data = tscadc;
+ cell->pdata_size = sizeof(*tscadc);
+
err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
TSCADC_CELLS, NULL, 0);
if (err < 0)
diff --git a/include/linux/mfd/ti_tscadc.h b/include/linux/mfd/ti_tscadc.h
index de314a6..3414883 100644
--- a/include/linux/mfd/ti_tscadc.h
+++ b/include/linux/mfd/ti_tscadc.h
@@ -117,15 +117,19 @@

#define ADC_CLK 3000000
#define MAX_CLK_DIV 7
+#define TOTAL_STEPS 16
+#define TOTAL_CHANNELS 8

-#define TSCADC_CELLS 1
+#define TSCADC_CELLS 2

enum tscadc_cells {
TSC_CELL,
+ ADC_CELL,
};

struct mfd_tscadc_board {
struct tsc_data *tsc_init;
+ struct adc_data *adc_init;
};

struct ti_tscadc_dev {
@@ -136,6 +140,9 @@ struct ti_tscadc_dev {

/* tsc device */
struct tscadc *tsc;
+
+ /* adc device */
+ struct adc_device *adc;
};

#endif
diff --git a/include/linux/platform_data/ti_adc.h b/include/linux/platform_data/ti_adc.h
new file mode 100644
index 0000000..5a89f1d
--- /dev/null
+++ b/include/linux/platform_data/ti_adc.h
@@ -0,0 +1,14 @@
+#ifndef __LINUX_TI_ADC_H
+#define __LINUX_TI_ADC_H
+
+/**
+ * struct adc_data ADC Input information
+ * @adc_channels: Number of analog inputs
+ * available for ADC.
+ */
+
+struct adc_data {
+ int adc_channels;
+};
+
+#endif
--
1.7.1

2012-08-30 07:56:44

by Patil, Rachna

[permalink] [raw]
Subject: [PATCH v2 1/5] input: TSC: ti_tscadc: Rename the existing touchscreen driver

Make way for addition of MFD driver.
The existing touchsreen driver is a MFD client.
For better readability we rename the file to
indicate its functionality as only touchscreen.

Signed-off-by: Patil, Rachna <[email protected]>
---
Changes in v2:
Missed changing the name of touchscreen header file
in the previous version.
Adding the same.

drivers/input/touchscreen/Kconfig | 4 ++--
drivers/input/touchscreen/Makefile | 2 +-
.../input/touchscreen/{ti_tscadc.c => ti_tsc.c} | 2 +-
include/linux/input/{ti_tscadc.h => ti_tsc.h} | 4 ++--
4 files changed, 6 insertions(+), 6 deletions(-)
rename drivers/input/touchscreen/{ti_tscadc.c => ti_tsc.c} (99%)
rename include/linux/input/{ti_tscadc.h => ti_tsc.h} (90%)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 1ba232c..68ac802 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -529,7 +529,7 @@ config TOUCHSCREEN_TOUCHWIN
To compile this driver as a module, choose M here: the
module will be called touchwin.

-config TOUCHSCREEN_TI_TSCADC
+config TOUCHSCREEN_TI_TSC
tristate "TI Touchscreen Interface"
depends on ARCH_OMAP2PLUS
help
@@ -539,7 +539,7 @@ config TOUCHSCREEN_TI_TSCADC
If unsure, say N.

To compile this driver as a module, choose M here: the
- module will be called ti_tscadc.
+ module will be called ti_tsc.

config TOUCHSCREEN_ATMEL_TSADCC
tristate "Atmel Touchscreen Interface"
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 178eb12..d579427 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -52,7 +52,7 @@ obj-$(CONFIG_TOUCHSCREEN_PIXCIR) += pixcir_i2c_ts.o
obj-$(CONFIG_TOUCHSCREEN_S3C2410) += s3c2410_ts.o
obj-$(CONFIG_TOUCHSCREEN_ST1232) += st1232.o
obj-$(CONFIG_TOUCHSCREEN_STMPE) += stmpe-ts.o
-obj-$(CONFIG_TOUCHSCREEN_TI_TSCADC) += ti_tscadc.o
+obj-$(CONFIG_TOUCHSCREEN_TI_TSC) += ti_tsc.o
obj-$(CONFIG_TOUCHSCREEN_TNETV107X) += tnetv107x-ts.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213) += touchit213.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
diff --git a/drivers/input/touchscreen/ti_tscadc.c b/drivers/input/touchscreen/ti_tsc.c
similarity index 99%
rename from drivers/input/touchscreen/ti_tscadc.c
rename to drivers/input/touchscreen/ti_tsc.c
index ec0a442..8e94c00 100644
--- a/drivers/input/touchscreen/ti_tscadc.c
+++ b/drivers/input/touchscreen/ti_tsc.c
@@ -24,7 +24,7 @@
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/io.h>
-#include <linux/input/ti_tscadc.h>
+#include <linux/input/ti_tsc.h>
#include <linux/delay.h>

#define REG_RAWIRQSTATUS 0x024
diff --git a/include/linux/input/ti_tscadc.h b/include/linux/input/ti_tsc.h
similarity index 90%
rename from include/linux/input/ti_tscadc.h
rename to include/linux/input/ti_tsc.h
index ad442a3..5da27d6 100644
--- a/include/linux/input/ti_tscadc.h
+++ b/include/linux/input/ti_tsc.h
@@ -1,5 +1,5 @@
-#ifndef __LINUX_TI_TSCADC_H
-#define __LINUX_TI_TSCADC_H
+#ifndef __LINUX_TI_TSC_H
+#define __LINUX_TI_TSC_H

/**
* struct tsc_data Touchscreen wire configuration
--
1.7.1

2012-08-30 07:57:22

by Patil, Rachna

[permalink] [raw]
Subject: [PATCH v2 2/5] MFD: ti_tscadc: Add support for TI's TSC/ADC MFDevice

Add the mfd core driver which supports touchscreen
and ADC.
With this patch we are only adding infrastructure to
support the MFD clients.

Signed-off-by: Patil, Rachna <[email protected]>
---
Changes in v2:
Merged "[PATCH 5/5] MFD: ti_tscadc: Add check on number of i/p channels",
pacth submitted in pervious version into this file.

drivers/mfd/Kconfig | 9 ++
drivers/mfd/Makefile | 1 +
drivers/mfd/ti_tscadc.c | 193 +++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/ti_tscadc.h | 133 ++++++++++++++++++++++++++++
4 files changed, 336 insertions(+), 0 deletions(-)
create mode 100644 drivers/mfd/ti_tscadc.c
create mode 100644 include/linux/mfd/ti_tscadc.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index d1facef..81eb815 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -94,6 +94,15 @@ config MFD_TI_SSP
To compile this driver as a module, choose M here: the
module will be called ti-ssp.

+config MFD_TI_TSCADC
+ tristate "TI ADC / Touch Screen chip support"
+ depends on ARCH_OMAP2PLUS
+ help
+ If you say yes here you get support for Texas Instruments series
+ of Touch Screen /ADC chips.
+ To compile this driver as a module, choose M here: the
+ module will be called ti_tscadc.
+
config HTC_EGPIO
bool "HTC EGPIO support"
depends on GENERIC_HARDIRQS && GPIOLIB && ARM
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 79dd22d..1537f74 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_HTC_I2CPLD) += htc-i2cpld.o
obj-$(CONFIG_MFD_DAVINCI_VOICECODEC) += davinci_voicecodec.o
obj-$(CONFIG_MFD_DM355EVM_MSP) += dm355evm_msp.o
obj-$(CONFIG_MFD_TI_SSP) += ti-ssp.o
+obj-$(CONFIG_MFD_TI_TSCADC) += ti_tscadc.o

obj-$(CONFIG_MFD_STA2X11) += sta2x11-mfd.o
obj-$(CONFIG_MFD_STMPE) += stmpe.o
diff --git a/drivers/mfd/ti_tscadc.c b/drivers/mfd/ti_tscadc.c
new file mode 100644
index 0000000..ac4bf7b
--- /dev/null
+++ b/drivers/mfd/ti_tscadc.c
@@ -0,0 +1,193 @@
+/*
+ * TI Touch Screen / ADC MFD driver
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/mfd/core.h>
+#include <linux/pm_runtime.h>
+#include <linux/mfd/ti_tscadc.h>
+
+static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
+{
+ return readl(tsadc->tscadc_base + reg);
+}
+
+static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
+ unsigned int val)
+{
+ writel(val, tsadc->tscadc_base + reg);
+}
+
+static void tscadc_idle_config(struct ti_tscadc_dev *config)
+{
+ unsigned int idleconfig;
+
+ idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
+ STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
+
+ tscadc_writel(config, REG_IDLECONFIG, idleconfig);
+}
+
+static int __devinit ti_tscadc_probe(struct platform_device *pdev)
+{
+ struct ti_tscadc_dev *tscadc;
+ struct resource *res;
+ struct clk *clk;
+ struct mfd_tscadc_board *pdata = pdev->dev.platform_data;
+ int irq;
+ int err, ctrl;
+ int clk_value, clock_rate;
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "Could not find platform data\n");
+ return -EINVAL;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no memory resource defined.\n");
+ return -EINVAL;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "no irq ID is specified.\n");
+ return -EINVAL;
+ }
+
+ /* Allocate memory for device */
+ tscadc = kzalloc(sizeof(struct ti_tscadc_dev), GFP_KERNEL);
+ if (!tscadc) {
+ dev_err(&pdev->dev, "failed to allocate memory.\n");
+ return -ENOMEM;
+ }
+ tscadc->dev = &pdev->dev;
+ tscadc->irq = irq;
+
+ res = request_mem_region(res->start, resource_size(res), pdev->name);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to reserve registers.\n");
+ err = -EBUSY;
+ goto err_free_mem;
+ }
+
+ tscadc->tscadc_base = ioremap(res->start, resource_size(res));
+ if (!tscadc->tscadc_base) {
+ dev_err(&pdev->dev, "failed to map registers.\n");
+ err = -ENOMEM;
+ goto err_release_mem_region;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_get_sync(&pdev->dev);
+
+ /*
+ * The TSC_ADC_Subsystem has 2 clock domains
+ * OCP_CLK and ADC_CLK.
+ * The ADC clock is expected to run at target of 3MHz,
+ * and expected to capture 12-bit data at a rate of 200 KSPS.
+ * The TSC_ADC_SS controller design assumes the OCP clock is
+ * at least 6x faster than the ADC clock.
+ */
+ clk = clk_get(&pdev->dev, "adc_tsc_fck");
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "failed to get TSC fck\n");
+ err = PTR_ERR(clk);
+ goto err_disable_clk;
+ }
+ clock_rate = clk_get_rate(clk);
+ clk_put(clk);
+ clk_value = clock_rate / ADC_CLK;
+ if (clk_value < MAX_CLK_DIV) {
+ dev_err(&pdev->dev, "clock input less than min clock requirement\n");
+ err = -EINVAL;
+ goto err_disable_clk;
+ }
+ /* TSCADC_CLKDIV needs to be configured to the value minus 1 */
+ clk_value = clk_value - 1;
+ tscadc_writel(tscadc, REG_CLKDIV, clk_value);
+
+ /* Set the control register bits */
+ ctrl = CNTRLREG_STEPCONFIGWRT |
+ CNTRLREG_TSCENB |
+ CNTRLREG_STEPID |
+ CNTRLREG_4WIRE;
+ tscadc_writel(tscadc, REG_CTRL, ctrl);
+
+ /* Set register bits for Idle Config Mode */
+ 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);
+
+ err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
+ TSCADC_CELLS, NULL, 0);
+ if (err < 0)
+ goto err_disable_clk;
+
+ platform_set_drvdata(pdev, tscadc);
+ return 0;
+
+err_disable_clk:
+ pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ iounmap(tscadc->tscadc_base);
+err_release_mem_region:
+ release_mem_region(res->start, resource_size(res));
+ mfd_remove_devices(tscadc->dev);
+err_free_mem:
+ kfree(tscadc);
+ return err;
+}
+
+static int __devexit ti_tscadc_remove(struct platform_device *pdev)
+{
+ struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev);
+ struct resource *res;
+
+ tscadc_writel(tscadc, REG_SE, 0x00);
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ iounmap(tscadc->tscadc_base);
+ release_mem_region(res->start, resource_size(res));
+
+ pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+
+ mfd_remove_devices(tscadc->dev);
+ kfree(tscadc);
+ return 0;
+}
+
+static struct platform_driver ti_tscadc_driver = {
+ .driver = {
+ .name = "ti_tscadc",
+ .owner = THIS_MODULE,
+ },
+ .probe = ti_tscadc_probe,
+ .remove = __devexit_p(ti_tscadc_remove),
+
+};
+
+module_platform_driver(ti_tscadc_driver);
+
+MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
+MODULE_AUTHOR("Rachna Patil <[email protected]>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/ti_tscadc.h b/include/linux/mfd/ti_tscadc.h
new file mode 100644
index 0000000..a700085
--- /dev/null
+++ b/include/linux/mfd/ti_tscadc.h
@@ -0,0 +1,133 @@
+#ifndef __LINUX_TI_TSCADC_MFD_H
+#define __LINUX_TI_TSCADC_MFD_H
+
+/*
+ * TI Touch Screen / ADC MFD driver
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/mfd/core.h>
+
+#define REG_RAWIRQSTATUS 0x024
+#define REG_IRQSTATUS 0x028
+#define REG_IRQENABLE 0x02C
+#define REG_IRQCLR 0x030
+#define REG_IRQWAKEUP 0x034
+#define REG_CTRL 0x040
+#define REG_ADCFSM 0x044
+#define REG_CLKDIV 0x04C
+#define REG_SE 0x054
+#define REG_IDLECONFIG 0x058
+#define REG_CHARGECONFIG 0x05C
+#define REG_CHARGEDELAY 0x060
+#define REG_STEPCONFIG(n) (0x64 + ((n - 1) * 8))
+#define REG_STEPDELAY(n) (0x68 + ((n - 1) * 8))
+#define REG_FIFO0CNT 0xE4
+#define REG_FIFO0THR 0xE8
+#define REG_FIFO1CNT 0xF0
+#define REG_FIFO1THR 0xF4
+#define REG_FIFO0 0x100
+#define REG_FIFO1 0x200
+
+/* Register Bitfields */
+/* Step Enable */
+#define STEPENB_MASK (0x1FFFF << 0)
+#define STEPENB(val) ((val) << 0)
+#define STPENB_STEPENB STEPENB(0x7FFF)
+
+/* IRQ enable */
+#define IRQENB_HW_PEN BIT(0)
+#define IRQENB_FIFO0THRES BIT(2)
+#define IRQENB_FIFO1THRES BIT(5)
+#define IRQENB_PENUP BIT(9)
+
+/* Step Configuration */
+#define STEPCONFIG_MODE_MASK (3 << 0)
+#define STEPCONFIG_MODE(val) ((val) << 0)
+#define STEPCONFIG_MODE_HWSYNC STEPCONFIG_MODE(2)
+#define STEPCONFIG_AVG_MASK (7 << 2)
+#define STEPCONFIG_AVG(val) ((val) << 2)
+#define STEPCONFIG_AVG_16 STEPCONFIG_AVG(4)
+#define STEPCONFIG_XPP BIT(5)
+#define STEPCONFIG_XNN BIT(6)
+#define STEPCONFIG_YPP BIT(7)
+#define STEPCONFIG_YNN BIT(8)
+#define STEPCONFIG_XNP BIT(9)
+#define STEPCONFIG_YPN BIT(10)
+#define STEPCONFIG_INM_MASK (0xF << 15)
+#define STEPCONFIG_INM(val) ((val) << 15)
+#define STEPCONFIG_INM_ADCREFM STEPCONFIG_INM(8)
+#define STEPCONFIG_INP_MASK (0xF << 19)
+#define STEPCONFIG_INP(val) ((val) << 19)
+#define STEPCONFIG_INP_AN2 STEPCONFIG_INP(2)
+#define STEPCONFIG_INP_AN3 STEPCONFIG_INP(3)
+#define STEPCONFIG_INP_AN4 STEPCONFIG_INP(4)
+#define STEPCONFIG_INP_ADCREFM STEPCONFIG_INP(8)
+#define STEPCONFIG_FIFO1 BIT(26)
+
+/* Delay register */
+#define STEPDELAY_OPEN_MASK (0x3FFFF << 0)
+#define STEPDELAY_OPEN(val) ((val) << 0)
+#define STEPCONFIG_OPENDLY STEPDELAY_OPEN(0x098)
+#define STEPDELAY_SAMPLE_MASK (0xFF << 24)
+#define STEPDELAY_SAMPLE(val) ((val) << 24)
+#define STEPCONFIG_SAMPLEDLY STEPDELAY_SAMPLE(0)
+
+/* Charge Config */
+#define STEPCHARGE_RFP_MASK (7 << 12)
+#define STEPCHARGE_RFP(val) ((val) << 12)
+#define STEPCHARGE_RFP_XPUL STEPCHARGE_RFP(1)
+#define STEPCHARGE_INM_MASK (0xF << 15)
+#define STEPCHARGE_INM(val) ((val) << 15)
+#define STEPCHARGE_INM_AN1 STEPCHARGE_INM(1)
+#define STEPCHARGE_INP_MASK (0xF << 19)
+#define STEPCHARGE_INP(val) ((val) << 19)
+#define STEPCHARGE_INP_AN1 STEPCHARGE_INP(1)
+#define STEPCHARGE_RFM_MASK (3 << 23)
+#define STEPCHARGE_RFM(val) ((val) << 23)
+#define STEPCHARGE_RFM_XNUR STEPCHARGE_RFM(1)
+
+/* Charge delay */
+#define CHARGEDLY_OPEN_MASK (0x3FFFF << 0)
+#define CHARGEDLY_OPEN(val) ((val) << 0)
+#define CHARGEDLY_OPENDLY CHARGEDLY_OPEN(1)
+
+/* Control register */
+#define CNTRLREG_TSCSSENB BIT(0)
+#define CNTRLREG_STEPID BIT(1)
+#define CNTRLREG_STEPCONFIGWRT BIT(2)
+#define CNTRLREG_POWERDOWN BIT(4)
+#define CNTRLREG_AFE_CTRL_MASK (3 << 5)
+#define CNTRLREG_AFE_CTRL(val) ((val) << 5)
+#define CNTRLREG_4WIRE CNTRLREG_AFE_CTRL(1)
+#define CNTRLREG_5WIRE CNTRLREG_AFE_CTRL(2)
+#define CNTRLREG_8WIRE CNTRLREG_AFE_CTRL(3)
+#define CNTRLREG_TSCENB BIT(7)
+
+#define ADC_CLK 3000000
+#define MAX_CLK_DIV 7
+
+#define TSCADC_CELLS 0
+
+struct mfd_tscadc_board {
+ struct tsc_data *tsc_init;
+};
+
+struct ti_tscadc_dev {
+ struct device *dev;
+ void __iomem *tscadc_base;
+ int irq;
+ struct mfd_cell cells[TSCADC_CELLS];
+};
+
+#endif
--
1.7.1

2012-08-30 19:42:07

by Jonathan Cameron

[permalink] [raw]
Subject: Re: [PATCH v2 4/5] IIO : ADC: tiadc: Add support of TI's ADC driver

On 08/30/2012 08:38 AM, Patil, Rachna wrote:
> This patch adds support for TI's ADC driver.
> This is a multifunctional device.
> Analog input lines are provided on which
> voltage measurements can be carried out.
> You can have upto 8 input lines.
>
Nice concise driver.

A few comments and questions inline. Nothing significant
really though... Half of them are me wanting to improve
my understanding of what is going on (and not have to
remember it in the future ;)

> Signed-off-by: Patil, Rachna <[email protected]>
> ---
> Changes in v2:
> Addressed review comments from Matthias Kaehlcke
>
> drivers/iio/adc/Kconfig | 7 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ti_adc.c | 216 ++++++++++++++++++++++++++++++++++
> drivers/mfd/ti_tscadc.c | 18 +++-
> include/linux/mfd/ti_tscadc.h | 9 ++-
> include/linux/platform_data/ti_adc.h | 14 ++
> 6 files changed, 263 insertions(+), 2 deletions(-)
> create mode 100644 drivers/iio/adc/ti_adc.c
> create mode 100644 include/linux/platform_data/ti_adc.h
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 8a78b4f..ad32df8 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -22,4 +22,11 @@ config AT91_ADC
> help
> Say yes here to build support for Atmel AT91 ADC.
>
> +config TI_ADC
> + tristate "TI's ADC driver"
> + depends on ARCH_OMAP2PLUS
> + help
> + Say yes here to build support for Texas Instruments ADC
> + driver which is also a MFD client.
> +
> endmenu
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 52eec25..a930cee 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -4,3 +4,4 @@
>
> obj-$(CONFIG_AD7266) += ad7266.o
> obj-$(CONFIG_AT91_ADC) += at91_adc.o
> +obj-$(CONFIG_TI_ADC) += ti_adc.o
> diff --git a/drivers/iio/adc/ti_adc.c b/drivers/iio/adc/ti_adc.c
> new file mode 100644
> index 0000000..d2e621c
> --- /dev/null
> +++ b/drivers/iio/adc/ti_adc.c
> @@ -0,0 +1,216 @@
> +/*
> + * TI ADC MFD driver
> + *
> + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation version 2.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <linux/iio/iio.h>
> +
> +#include <linux/mfd/ti_tscadc.h>
> +#include <linux/platform_data/ti_adc.h>
> +
> +struct adc_device {
> + struct ti_tscadc_dev *mfd_tscadc;
> + struct iio_dev *idev;
> + int channels;
> +};
> +
> +static unsigned int adc_readl(struct adc_device *adc, unsigned int reg)
> +{
> + return readl(adc->mfd_tscadc->tscadc_base + reg);
> +}
> +
> +static void adc_writel(struct adc_device *adc, unsigned int reg,
> + unsigned int val)
> +{
> + writel(val, adc->mfd_tscadc->tscadc_base + reg);
> +}
> +
> +static void adc_step_config(struct adc_device *adc_dev)
> +{
> + unsigned int stepconfig;
> + int i, channels = 0, steps;
> +
> + /*

Don't suppose you could tell us what the steps actually are?
It's not a term I've come across before and right now I can't
seem to find the relevant datasheet (and am inherently lazy ;)

> + * There are 16 configurable steps and 8 analog input
> + * lines available which are shared between Touchscreen and ADC.
> + *
> + * Steps backwards i.e. from 16 towards 0 are used by ADC
> + * depending on number of input lines needed.
> + * Channel would represent which analog input
> + * needs to be given to ADC to digitalize data.
> + */
> +
> + steps = TOTAL_STEPS - adc_dev->channels;
> + channels = TOTAL_CHANNELS - adc_dev->channels;
> +
> + stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1;
> +
> + for (i = (steps + 1); i <= TOTAL_STEPS; i++) {
> + adc_writel(adc_dev, REG_STEPCONFIG(i),
> + stepconfig | STEPCONFIG_INP(channels));
> + adc_writel(adc_dev, REG_STEPDELAY(i),
> + STEPCONFIG_OPENDLY);
> + channels++;
> + }
> + adc_writel(adc_dev, REG_SE, STPENB_STEPENB);
> +}
> +
> +static int tiadc_channel_init(struct iio_dev *idev, struct adc_device *adc_dev)
> +{
> + struct iio_chan_spec *chan_array;
> + int i;
> +
> + idev->num_channels = adc_dev->channels;
Given adc_dev is just used for this why not just pass in the number of channels?

> + chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
> + GFP_KERNEL);
> +
> + if (chan_array == NULL)
> + return -ENOMEM;
> +
> + for (i = 0; i < (idev->num_channels); i++) {
> + struct iio_chan_spec *chan = chan_array + i;
> + chan->type = IIO_VOLTAGE;
> + chan->indexed = 1;
> + chan->channel = i;
You don't use the buffered interfaces so don't need anything below here.
> + chan->scan_type.sign = 'u';
> + chan->scan_type.realbits = 12;
> + chan->scan_type.storagebits = 32;
> + chan->scan_type.shift = 0;
> + }
> +
> + idev->channels = chan_array;
whilst not critical it's a nice convention to drop in a blank line before
return statements.. Just makes it slightly easier to parse.
> + return idev->num_channels;
> +}
> +
channels would be slightly more acurate I think...
> +static void tiadc_channel_remove(struct iio_dev *idev)
> +{
> + kfree(idev->channels);
> +}
> +
> +static int tiadc_read_raw(struct iio_dev *idev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct adc_device *adc_dev = iio_priv(idev);
> + int i;
> + unsigned int fifo1count, readx1;
> +
Given adc_dev is only passed directly to adc_readl
and adc_writel you could make those functions take
the iio_dev instead..
> + fifo1count = adc_readl(adc_dev, REG_FIFO1CNT);
What are the semantics of this? Is the channel
guaranteed to be there? Is this just about ensuring we
always get the latest reading?
This is definitely a case where a little commenting would
help the reader :)
> + for (i = 0; i < fifo1count; i++) {
> + readx1 = adc_readl(adc_dev, REG_FIFO1);
> + if (i == chan->channel) {
> + readx1 = readx1 & 0xfff;
> + *val = readx1;
might as well combine the two lines above...
> + }
> + }
> + adc_writel(adc_dev, REG_SE, STPENB_STEPENB);
> + return IIO_VAL_INT;
> +}
> +
> +static const struct iio_info tiadc_info = {
> + .read_raw = &tiadc_read_raw,
> +};
> +
> +static int __devinit tiadc_probe(struct platform_device *pdev)
> +{
> + struct iio_dev *idev;
> + int err;
> + struct adc_device *adc_dev = NULL;
I don't think there is any reason to initialize adc_dev...

> + struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
> + struct mfd_tscadc_board *pdata;
> +
> + pdata = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data;
> + if (!pdata || !pdata->adc_init) {
> + dev_err(tscadc_dev->dev, "Could not find platform data\n");
> + return -EINVAL;
> + }
> +
> + idev = iio_device_alloc(sizeof(struct adc_device));
> + if (idev == NULL) {
> + dev_err(&pdev->dev, "failed to allocate iio device.\n");
> + err = -ENOMEM;
> + goto err_allocate;
> + }
> + adc_dev = iio_priv(idev);
> +
> + tscadc_dev->adc = adc_dev;
> + adc_dev->mfd_tscadc = tscadc_dev;
> + adc_dev->idev = idev;

hmm.. this is getting a bit circular... You could store the iio_dev
pointer in tscadc_dev intead of the adc_dev one thus I think
avoiding the need for this.. Still I guess it may be best to leave
it as it currently is for consistency with the input driver.


> + adc_dev->channels = pdata->adc_init->adc_channels;
> +
> + idev->dev.parent = &pdev->dev;
> + idev->name = dev_name(&pdev->dev);
> + idev->modes = INDIO_DIRECT_MODE;
> + idev->info = &tiadc_info;
> +
> + adc_step_config(adc_dev);
> +
> + err = tiadc_channel_init(idev, adc_dev);
> + if (err < 0)
> + goto err_cleanup_channels;
> +
> + err = iio_device_register(idev);
> + if (err)
> + goto err_unregister;
> +
> + dev_info(&pdev->dev, "attached adc driver\n");
> + platform_set_drvdata(pdev, idev);
> +
> + return 0;
> +
> +err_unregister:
> + tiadc_channel_remove(idev);
> +err_cleanup_channels:
> + iio_device_unregister(idev);
> + iio_device_free(idev);
> +err_allocate:
> + return err;
> +}
> +
> +static int __devexit tiadc_remove(struct platform_device *pdev)
> +{
> + struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
> + struct adc_device *adc_dev = tscadc_dev->adc;
> + struct iio_dev *idev = adc_dev->idev;
> +
> + iio_device_unregister(idev);
> + tiadc_channel_remove(idev);
> +
> + tscadc_dev->adc = NULL;
> +
> + iio_device_free(idev);
> + return 0;
> +}
> +
> +static struct platform_driver tiadc_driver = {
> + .driver = {
> + .name = "tiadc",
> + .owner = THIS_MODULE,
> + },
> + .probe = tiadc_probe,
> + .remove = __devexit_p(tiadc_remove),
> +};
> +
> +module_platform_driver(tiadc_driver);
> +
> +MODULE_DESCRIPTION("TI ADC controller driver");
> +MODULE_AUTHOR("Rachna Patil <[email protected]>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/mfd/ti_tscadc.c b/drivers/mfd/ti_tscadc.c
> index f26e53b..9dbd6d0 100644
> --- a/drivers/mfd/ti_tscadc.c
> +++ b/drivers/mfd/ti_tscadc.c
> @@ -23,6 +23,7 @@
> #include <linux/pm_runtime.h>
> #include <linux/mfd/ti_tscadc.h>
> #include <linux/input/ti_tsc.h>
> +#include <linux/platform_data/ti_adc.h>
>
> static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
> {
> @@ -55,14 +56,23 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
> int irq;
> int err, ctrl;
> int clk_value, clock_rate;
> - int tsc_wires;
> + int tsc_wires, adc_channels = 0, total_channels;
>
> if (!pdata) {
> dev_err(&pdev->dev, "Could not find platform data\n");
> return -EINVAL;
> }
>
> + if (pdata->adc_init)
> + adc_channels = pdata->adc_init->adc_channels;
> +
> tsc_wires = pdata->tsc_init->wires;
> + total_channels = tsc_wires + adc_channels;
> +
> + if (total_channels > 8) {
> + dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
> + return -EINVAL;
> + }
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!res) {
> @@ -149,6 +159,12 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
> cell->platform_data = tscadc;
> cell->pdata_size = sizeof(*tscadc);
>
> + /* ADC Cell */
> + cell = &tscadc->cells[ADC_CELL];
> + cell->name = "tiadc";
> + cell->platform_data = tscadc;
> + cell->pdata_size = sizeof(*tscadc);
> +
> err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
> TSCADC_CELLS, NULL, 0);
> if (err < 0)
> diff --git a/include/linux/mfd/ti_tscadc.h b/include/linux/mfd/ti_tscadc.h
> index de314a6..3414883 100644
> --- a/include/linux/mfd/ti_tscadc.h
> +++ b/include/linux/mfd/ti_tscadc.h
> @@ -117,15 +117,19 @@
>
> #define ADC_CLK 3000000
> #define MAX_CLK_DIV 7
> +#define TOTAL_STEPS 16
> +#define TOTAL_CHANNELS 8
>
> -#define TSCADC_CELLS 1
> +#define TSCADC_CELLS 2
>
> enum tscadc_cells {
> TSC_CELL,
> + ADC_CELL,
> };
>
> struct mfd_tscadc_board {
> struct tsc_data *tsc_init;
> + struct adc_data *adc_init;
> };
>
> struct ti_tscadc_dev {
> @@ -136,6 +140,9 @@ struct ti_tscadc_dev {
>
> /* tsc device */
> struct tscadc *tsc;
> +
> + /* adc device */
> + struct adc_device *adc;
> };
>
> #endif
> diff --git a/include/linux/platform_data/ti_adc.h b/include/linux/platform_data/ti_adc.h
> new file mode 100644
> index 0000000..5a89f1d
> --- /dev/null
> +++ b/include/linux/platform_data/ti_adc.h
> @@ -0,0 +1,14 @@
> +#ifndef __LINUX_TI_ADC_H
> +#define __LINUX_TI_ADC_H
> +
> +/**
> + * struct adc_data ADC Input information
> + * @adc_channels: Number of analog inputs
> + * available for ADC.
> + */
> +
> +struct adc_data {
> + int adc_channels;
> +};
> +
> +#endif
>

2012-08-31 10:40:49

by Patil, Rachna

[permalink] [raw]
Subject: RE: [PATCH v2 4/5] IIO : ADC: tiadc: Add support of TI's ADC driver

Hi,

On Fri, Aug 31, 2012 at 01:12:01, Jonathan Cameron wrote:
> On 08/30/2012 08:38 AM, Patil, Rachna wrote:
> > This patch adds support for TI's ADC driver.
> > This is a multifunctional device.
> > Analog input lines are provided on which voltage measurements can be
> > carried out.
> > You can have upto 8 input lines.
> >
> Nice concise driver.
>
> A few comments and questions inline. Nothing significant really though... Half of them are me wanting to improve my understanding of what is going on (and not have to remember it in the future ;)

Thanks for the comments. Please find my reply inline.

>
> > Signed-off-by: Patil, Rachna <[email protected]>
> > ---
> > Changes in v2:
> > Addressed review comments from Matthias Kaehlcke
> >
> > drivers/iio/adc/Kconfig | 7 +
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/ti_adc.c | 216 ++++++++++++++++++++++++++++++++++
> > drivers/mfd/ti_tscadc.c | 18 +++-
> > include/linux/mfd/ti_tscadc.h | 9 ++-
> > include/linux/platform_data/ti_adc.h | 14 ++
> > 6 files changed, 263 insertions(+), 2 deletions(-) create mode
> > 100644 drivers/iio/adc/ti_adc.c create mode 100644
> > include/linux/platform_data/ti_adc.h
> >
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index
> > 8a78b4f..ad32df8 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -22,4 +22,11 @@ config AT91_ADC
> > help
> > Say yes here to build support for Atmel AT91 ADC.
> >
> > +config TI_ADC
> > + tristate "TI's ADC driver"
> > + depends on ARCH_OMAP2PLUS
> > + help
> > + Say yes here to build support for Texas Instruments ADC
> > + driver which is also a MFD client.
> > +
> > endmenu
> > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index
> > 52eec25..a930cee 100644
> > --- a/drivers/iio/adc/Makefile
> > +++ b/drivers/iio/adc/Makefile
> > @@ -4,3 +4,4 @@
> >
> > obj-$(CONFIG_AD7266) += ad7266.o
> > obj-$(CONFIG_AT91_ADC) += at91_adc.o
> > +obj-$(CONFIG_TI_ADC) += ti_adc.o
> > diff --git a/drivers/iio/adc/ti_adc.c b/drivers/iio/adc/ti_adc.c new
> > file mode 100644 index 0000000..d2e621c
> > --- /dev/null
> > +++ b/drivers/iio/adc/ti_adc.c
> > @@ -0,0 +1,216 @@
> > +/*
> > + * TI ADC MFD driver
> > + *
> > + * Copyright (C) 2012 Texas Instruments Incorporated -
> > +http://www.ti.com/
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License as
> > + * published by the Free Software Foundation version 2.
> > + *
> > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> > + * kind, whether express or implied; without even the implied
> > +warranty
> > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/init.h>
> > +#include <linux/kernel.h>
> > +#include <linux/err.h>
> > +#include <linux/module.h>
> > +#include <linux/slab.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/io.h>
> > +#include <linux/iio/iio.h>
> > +
> > +#include <linux/mfd/ti_tscadc.h>
> > +#include <linux/platform_data/ti_adc.h>
> > +
> > +struct adc_device {
> > + struct ti_tscadc_dev *mfd_tscadc;
> > + struct iio_dev *idev;
> > + int channels;
> > +};
> > +
> > +static unsigned int adc_readl(struct adc_device *adc, unsigned int
> > +reg) {
> > + return readl(adc->mfd_tscadc->tscadc_base + reg); }
> > +
> > +static void adc_writel(struct adc_device *adc, unsigned int reg,
> > + unsigned int val)
> > +{
> > + writel(val, adc->mfd_tscadc->tscadc_base + reg); }
> > +
> > +static void adc_step_config(struct adc_device *adc_dev) {
> > + unsigned int stepconfig;
> > + int i, channels = 0, steps;
> > +
> > + /*
>
> Don't suppose you could tell us what the steps actually are?
> It's not a term I've come across before and right now I can't seem to find the relevant datasheet (and am inherently lazy ;)

The user must first program the Step Configuration registers in order to configure a channel input to be sampled. There are 16 programmable Step Configuration registers which are used by the sequencer to control which switches to turn on or off (inputs to the Analog front end used for touchscreen), which channel to sample, and which mode to use (HW triggered or SW enabled, one-shot or continuous mode), averaging, where to save the FIFO data, etc. The sequencer is completely controlled by software and behaves accordingly to how the Step Registers are programmed. A step is the general term for sampling a channel input.

>
> > + * There are 16 configurable steps and 8 analog input
> > + * lines available which are shared between Touchscreen and ADC.
> > + *
> > + * Steps backwards i.e. from 16 towards 0 are used by ADC
> > + * depending on number of input lines needed.
> > + * Channel would represent which analog input
> > + * needs to be given to ADC to digitalize data.
> > + */
> > +
> > + steps = TOTAL_STEPS - adc_dev->channels;
> > + channels = TOTAL_CHANNELS - adc_dev->channels;
> > +
> > + stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1;
> > +
> > + for (i = (steps + 1); i <= TOTAL_STEPS; i++) {
> > + adc_writel(adc_dev, REG_STEPCONFIG(i),
> > + stepconfig | STEPCONFIG_INP(channels));
> > + adc_writel(adc_dev, REG_STEPDELAY(i),
> > + STEPCONFIG_OPENDLY);
> > + channels++;
> > + }
> > + adc_writel(adc_dev, REG_SE, STPENB_STEPENB); }
> > +
> > +static int tiadc_channel_init(struct iio_dev *idev, struct adc_device
> > +*adc_dev) {
> > + struct iio_chan_spec *chan_array;
> > + int i;
> > +
> > + idev->num_channels = adc_dev->channels;
> Given adc_dev is just used for this why not just pass in the number of channels?

Yes, I can just pass the channel information directly.

>
> > + chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
> > + GFP_KERNEL);
> > +
> > + if (chan_array == NULL)
> > + return -ENOMEM;
> > +
> > + for (i = 0; i < (idev->num_channels); i++) {
> > + struct iio_chan_spec *chan = chan_array + i;
> > + chan->type = IIO_VOLTAGE;
> > + chan->indexed = 1;
> > + chan->channel = i;
> You don't use the buffered interfaces so don't need anything below here.

Ok. I will drop this.

> > + chan->scan_type.sign = 'u';
> > + chan->scan_type.realbits = 12;
> > + chan->scan_type.storagebits = 32;
> > + chan->scan_type.shift = 0;
> > + }
> > +
> > + idev->channels = chan_array;
> whilst not critical it's a nice convention to drop in a blank line before return statements.. Just makes it slightly easier to parse.

Ok. I will add blank line here.

> > + return idev->num_channels;
> > +}
> > +
> channels would be slightly more acurate I think...

True, I will change this.

> > +static void tiadc_channel_remove(struct iio_dev *idev) {
> > + kfree(idev->channels);
> > +}
> > +
> > +static int tiadc_read_raw(struct iio_dev *idev,
> > + struct iio_chan_spec const *chan,
> > + int *val, int *val2, long mask)
> > +{
> > + struct adc_device *adc_dev = iio_priv(idev);
> > + int i;
> > + unsigned int fifo1count, readx1;
> > +
> Given adc_dev is only passed directly to adc_readl and adc_writel you could make those functions take the iio_dev instead..

adc_dev holds base address of registers to be accessed. Passing iio_dev does not serve the purpose.

> > + fifo1count = adc_readl(adc_dev, REG_FIFO1CNT);
> What are the semantics of this? Is the channel guaranteed to be there? Is this just about ensuring we always get the latest reading?
> This is definitely a case where a little commenting would help the reader :)

This is not a channel. Here I am reading number of words present in FIFO1.
The IP has 2 FIFO's and ADC uses FIFO1.
In the next steps I read all the data in FIFO1, and return only the ADC value of channel user has asked for.
The IP has a sequencer which starts from the 1st step configured. If one has configured for all 8 channels available and is trying to read
Data on only one of the lines, Data pertaining to other lines is also still generated.
We need to flush this data, so that when user tries to access any other channel, the latest value on the channel is read.

I will add comments here.

> > + for (i = 0; i < fifo1count; i++) {
> > + readx1 = adc_readl(adc_dev, REG_FIFO1);
> > + if (i == chan->channel) {
> > + readx1 = readx1 & 0xfff;
> > + *val = readx1;
> might as well combine the two lines above...

Yes. I can do this.

> > + }
> > + }
> > + adc_writel(adc_dev, REG_SE, STPENB_STEPENB);
> > + return IIO_VAL_INT;
> > +}
> > +
> > +static const struct iio_info tiadc_info = {
> > + .read_raw = &tiadc_read_raw,
> > +};
> > +
> > +static int __devinit tiadc_probe(struct platform_device *pdev) {
> > + struct iio_dev *idev;
> > + int err;
> > + struct adc_device *adc_dev = NULL;
> I don't think there is any reason to initialize adc_dev...

Ok. I will drop this.

>
> > + struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
> > + struct mfd_tscadc_board *pdata;
> > +
> > + pdata = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data;
> > + if (!pdata || !pdata->adc_init) {
> > + dev_err(tscadc_dev->dev, "Could not find platform data\n");
> > + return -EINVAL;
> > + }
> > +
> > + idev = iio_device_alloc(sizeof(struct adc_device));
> > + if (idev == NULL) {
> > + dev_err(&pdev->dev, "failed to allocate iio device.\n");
> > + err = -ENOMEM;
> > + goto err_allocate;
> > + }
> > + adc_dev = iio_priv(idev);
> > +
> > + tscadc_dev->adc = adc_dev;
> > + adc_dev->mfd_tscadc = tscadc_dev;
> > + adc_dev->idev = idev;
>
> hmm.. this is getting a bit circular... You could store the iio_dev pointer in tscadc_dev intead of the adc_dev one thus I think avoiding the need for this.. Still I guess it may be best to leave it as it currently is for consistency with the input driver.

Yes, this is in consistence with input driver.

<SNIP>

Regards,
Rachna