Re: [PATCH 2/2] iio: exynos-adc: add experimental touchscreen support

Arnd Bergmann
2014-07-21T10:26:46Z

On Monday 21 July 2014 12:23:58 Arnd Bergmann wrote:
>
> Thanks a lot for the review! I'll send out the new version after some build testing.

Here are the changes I did to the adc driver based on the review comments.
I'll start a new thread for the updated version that includes the changes.

diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index 3d2caea05977..823d7ebc7f52 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -67,6 +67,9 @@

#define ADC_S3C2410_CON_SELMUX(x) (((x)&0x7)<<3)

+/* touch screen always uses channel 0 */
+#define ADC_S3C2410_MUX_TS 0
+
/* ADCTSC Register Bits */
#define ADC_S3C2443_TSC_UD_SEN (1u << 8)
#define ADC_S3C2410_TSC_YM_SEN (1u << 7)
@@ -106,6 +109,7 @@
#define ADC_CON_EN_START (1u << 0)
#define ADC_DATX_PRESSED (1u << 15)
#define ADC_DATX_MASK 0xFFF
+#define ADC_DATY_MASK 0xFFF

#define EXYNOS_ADC_TIMEOUT (msecs_to_jiffies(100))

@@ -123,10 +127,12 @@ struct exynos_adc {

struct completion completion;

- bool read_ts;
u32 value;
- u32 value2;
unsigned int version;
+
+ bool read_ts;
+ u32 ts_x;
+ u32 ts_y;
};

struct exynos_adc_data {
@@ -396,21 +402,14 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
return ret;
}

-static int exynos_read_s3c64xx_ts(struct iio_dev *indio_dev,
- struct iio_chan_spec const *chan,
- int *val,
- int *val2,
- long mask)
+static int exynos_read_s3c64xx_ts(struct iio_dev *indio_dev, int *x, int *y)
{
struct exynos_adc *info = iio_priv(indio_dev);
unsigned long timeout;
int ret;

- if (mask != IIO_CHAN_INFO_RAW)
- return -EINVAL;
-
mutex_lock(&indio_dev->mlock);
- info->read_ts = 1;
+ info->read_ts = true;

reinit_completion(&info->completion);

@@ -418,7 +417,7 @@ static int exynos_read_s3c64xx_ts(struct iio_dev *indio_dev,
ADC_V1_TSC(info->regs));

/* Select the ts channel to be used and Trigger conversion */
- info->data->start_conv(info, 0);
+ info->data->start_conv(info, ADC_S3C2410_MUX_TS);

timeout = wait_for_completion_timeout
(&info->completion, EXYNOS_ADC_TIMEOUT);
@@ -428,12 +427,12 @@ static int exynos_read_s3c64xx_ts(struct iio_dev *indio_dev,
info->data->init_hw(info);
ret = -ETIMEDOUT;
} else {
- *val = info->value;
- *val2 = info->value2;
- ret = IIO_VAL_INT;
+ *x = info->ts_x;
+ *y = info->ts_y;
+ ret = 0;
}

- info->read_ts = 0;
+ info->read_ts = false;
mutex_unlock(&indio_dev->mlock);

return ret;
@@ -445,8 +444,8 @@ static irqreturn_t exynos_adc_isr(int irq, void *dev_id)

/* Read value */
if (info->read_ts) {
- info->value = readl(ADC_V1_DATX(info->regs)) & ADC_DATX_MASK;
- info->value2 = readl(ADC_V1_DATY(info->regs)) & ADC_DATX_MASK;
+ info->ts_x = readl(ADC_V1_DATX(info->regs));
+ info->ts_y = readl(ADC_V1_DATY(info->regs));
writel(ADC_TSC_WAIT4INT | ADC_S3C2443_TSC_UD_SEN, ADC_V1_TSC(info->regs));
} else {
info->value = readl(ADC_V1_DATX(info->regs)) & ADC_DATX_MASK;
@@ -477,7 +476,7 @@ static irqreturn_t exynos_ts_isr(int irq, void *dev_id)
int ret;

do {
- ret =exynos_read_s3c64xx_ts(dev, NULL, &x, &y, IIO_CHAN_INFO_RAW);
+ ret = exynos_read_s3c64xx_ts(dev, &x, &y);
if (ret == -ETIMEDOUT)
break;

@@ -486,11 +485,15 @@ static irqreturn_t exynos_ts_isr(int irq, void *dev_id)
break;

input_report_abs(info->input, ABS_X, x & ADC_DATX_MASK);
- input_report_abs(info->input, ABS_Y, y & ADC_DATX_MASK);
+ input_report_abs(info->input, ABS_Y, y & ADC_DATY_MASK);
input_report_key(info->input, BTN_TOUCH, 1);
input_sync(info->input);

msleep(1);
+
+ /* device may have been closed while touched */
+ if (!info->input->users)
+ return IRQ_HANDLED;
} while (1);

input_report_key(info->input, BTN_TOUCH, 0);
@@ -552,10 +555,28 @@ static int exynos_adc_remove_devices(struct device *dev, void *c)
return 0;
}

+static int exynos_adc_ts_open(struct input_dev *dev)
+{
+ struct exynos_adc *info = input_get_drvdata(dev);
+
+ return request_threaded_irq(info->tsirq, NULL, exynos_ts_isr,
+ 0, "touchscreen", info);
+}
+
+static void exynos_adc_ts_close(struct input_dev *dev)
+{
+ struct exynos_adc *info = input_get_drvdata(dev);
+
+ free_irq(info->tsirq, info);
+}
+
static int exynos_adc_ts_init(struct exynos_adc *info)
{
int ret;

+ if (info->tsirq <= 0)
+ return -ENODEV;
+
info->input = input_allocate_device();
if (!info->input)
return -ENOMEM;
@@ -566,33 +587,17 @@ static int exynos_adc_ts_init(struct exynos_adc *info)
input_set_abs_params(info->input, ABS_X, 0, 0x3FF, 0, 0);
input_set_abs_params(info->input, ABS_Y, 0, 0x3FF, 0, 0);

- /* data from s3c2410_ts driver */
info->input->name = "S3C24xx TouchScreen";
info->input->id.bustype = BUS_HOST;
- info->input->id.vendor = 0xDEAD;
- info->input->id.product = 0xBEEF;
- info->input->id.version = 0x0200;
+ info->input->open = exynos_adc_ts_open;
+ info->input->close = exynos_adc_ts_close;
+
+ input_set_drvdata(info->input, info);

ret = input_register_device(info->input);
- if (ret) {
+ if (ret)
input_free_device(info->input);
- goto err;
- }
-
- if (info->tsirq > 0)
- ret = request_threaded_irq(info->irq, NULL, exynos_ts_isr,
- 0, "touchscreen", info);
- if (ret < 0) {
- dev_err(info->dev, "failed requesting touchsccreen irq, irq = %d\n",
- info->irq);
- goto err_input;
- }
-
- return 0;

-err_input:
- input_unregister_device(info->input);
-err:
return ret;
}

@@ -602,7 +607,7 @@ static int exynos_adc_probe(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
struct iio_dev *indio_dev = NULL;
struct resource *mem;
- bool has_ts;
+ bool has_ts = false;
int ret = -ENODEV;
int irq;

@@ -711,7 +716,10 @@ static int exynos_adc_probe(struct platform_device *pdev)
if (info->data->init_hw)
info->data->init_hw(info);

- has_ts = of_property_read_bool(pdev->dev.of_node, "has-touchscreen");
+ /* leave out any TS related code if unreachable */
+ if (IS_BUILTIN(CONFIG_INPUT) ||
+ (IS_MODULE(CONFIG_INPUT) && config_enabled(MODULE)))
+ has_ts = of_property_read_bool(pdev->dev.of_node, "has-touchscreen");
if (has_ts)
ret = exynos_adc_ts_init(info);
if (ret)
@@ -752,7 +760,7 @@ static int exynos_adc_remove(struct platform_device *pdev)
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct exynos_adc *info = iio_priv(indio_dev);

- input_free_device(info->input);
+ input_unregister_device(info->input);
device_for_each_child(&indio_dev->dev, NULL,
exynos_adc_remove_devices);
iio_device_unregister(indio_dev);