Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756146AbaGVSJN (ORCPT ); Tue, 22 Jul 2014 14:09:13 -0400 Received: from mail-pd0-f174.google.com ([209.85.192.174]:38871 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754840AbaGVSJJ (ORCPT ); Tue, 22 Jul 2014 14:09:09 -0400 Date: Tue, 22 Jul 2014 11:09:04 -0700 From: Dmitry Torokhov To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, linux-iio@vger.kernel.org, kgene.kim@samsung.com, pawel.moll@arm.com, t.figa@samsung.com, linux-kernel@vger.kernel.org, Chanwoo Choi , kyungmin.park@samsung.com, linux-samsung-soc@vger.kernel.org, Jonathan Cameron , Ben Dooks , galak@codeaurora.org, ch.naveen@samsung.com, linux-input , heiko.stuebner@bq.com Subject: Re: [PATCH v2] iio: exynos-adc: add experimental touchscreen support Message-ID: <20140722180904.GB5489@core.coreip.homeip.net> References: <5068889.1KfVx3ksNo@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5068889.1KfVx3ksNo@wuerfel> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 22, 2014 at 03:03:12PM +0200, Arnd Bergmann wrote: > This adds support for the touchscreen on Samsung s3c64xx. > The driver is completely untested but shows roughly how > it could be done, following the example of the at91 driver. > > Open questions include: > > - compared to the old plat-samsung/adc driver, there is > no support for prioritizing ts over other clients, nor > for oversampling. From my reading of the code, the > priorities didn't actually have any effect at all, but > the oversampling might be needed. Maybe the original > authors have some insight. > > - We probably need to add support for platform_data as well, > I've skipped this so far. > > Signed-off-by: Arnd Bergmann > --- > This should address all previous comments, and I've also added > a write to ADC_V1_DLY() as the old driver does. > > diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt > index cad81b666a67..ba30836c73cb 100644 > --- a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt > +++ b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt > @@ -43,6 +43,10 @@ Required properties: > and compatible ADC block) > - vdd-supply VDD input supply. > > +Optional properties: > +- has-touchscreen: If present, indicates that a touchscreen is > + connected an usable. > + > Note: child nodes can be added for auto probing from device tree. > > Example: adding device info in dtsi file > diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c > index 420c5cda09c3..3b684a117b9c 100644 > --- a/drivers/iio/adc/exynos_adc.c > +++ b/drivers/iio/adc/exynos_adc.c > @@ -34,6 +34,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -66,6 +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) > @@ -103,24 +107,32 @@ > > /* Bit definitions common for ADC_V1 and ADC_V2 */ > #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)) > > struct exynos_adc { > struct exynos_adc_data *data; > struct device *dev; > + struct input_dev *input; > void __iomem *regs; > void __iomem *enable_reg; > struct clk *clk; > struct clk *sclk; > unsigned int irq; > + unsigned int tsirq; > struct regulator *vdd; > > struct completion completion; > > u32 value; > unsigned int version; > + > + bool read_ts; > + u32 ts_x; > + u32 ts_y; > }; > > struct exynos_adc_data { > @@ -205,6 +217,9 @@ static void exynos_adc_v1_init_hw(struct exynos_adc *info) > /* Enable 12-bit ADC resolution */ > con1 |= ADC_V1_CON_RES; > writel(con1, ADC_V1_CON(info->regs)); > + > + /* set default touchscreen delay */ > + writel(10000, ADC_V1_DLY(info->regs)); > } > > static void exynos_adc_v1_exit_hw(struct exynos_adc *info) > @@ -390,12 +405,54 @@ static int exynos_read_raw(struct iio_dev *indio_dev, > return ret; > } > > +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; > + > + mutex_lock(&indio_dev->mlock); > + info->read_ts = true; > + > + reinit_completion(&info->completion); > + > + writel(ADC_S3C2410_TSC_PULL_UP_DISABLE | ADC_TSC_AUTOPST, > + ADC_V1_TSC(info->regs)); > + > + /* Select the ts channel to be used and Trigger conversion */ > + info->data->start_conv(info, ADC_S3C2410_MUX_TS); > + > + timeout = wait_for_completion_timeout > + (&info->completion, EXYNOS_ADC_TIMEOUT); > + if (timeout == 0) { > + dev_warn(&indio_dev->dev, "Conversion timed out! Resetting\n"); > + if (info->data->init_hw) > + info->data->init_hw(info); > + ret = -ETIMEDOUT; > + } else { > + *x = info->ts_x; > + *y = info->ts_y; > + ret = 0; > + } > + > + info->read_ts = false; > + mutex_unlock(&indio_dev->mlock); > + > + return ret; > +} > + > static irqreturn_t exynos_adc_isr(int irq, void *dev_id) > { > struct exynos_adc *info = (struct exynos_adc *)dev_id; > > /* Read value */ > - info->value = readl(ADC_V1_DATX(info->regs)) & ADC_DATX_MASK; > + if (info->read_ts) { > + 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; > + } > > /* clear irq */ > if (info->data->clear_irq) > @@ -406,6 +463,46 @@ static irqreturn_t exynos_adc_isr(int irq, void *dev_id) > return IRQ_HANDLED; > } > > +/* > + * Here we (ab)use a threaded interrupt handler to stay running > + * for as long as the touchscreen remains pressed, we report > + * a new event with the latest data and then sleep until the > + * next timer tick. This mirrors the behavior of the old > + * driver, with much less code. > + */ > +static irqreturn_t exynos_ts_isr(int irq, void *dev_id) > +{ > + struct exynos_adc *info = dev_id; > + struct iio_dev *dev = dev_get_drvdata(info->dev); > + u32 x, y; > + bool pressed; > + int ret; > + > + while (info->input->users) { > + ret = exynos_read_s3c64xx_ts(dev, &x, &y); > + if (ret == -ETIMEDOUT) > + break; > + > + pressed = x & y & ADC_DATX_PRESSED; > + if (!pressed) { > + input_report_key(info->input, BTN_TOUCH, 0); > + input_sync(info->input); > + break; > + } > + > + input_report_abs(info->input, ABS_X, x & 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); > + }; > + > + writel(0, ADC_V1_CLRINTPNDNUP(info->regs)); > + > + return IRQ_HANDLED; > +} > + > static int exynos_adc_reg_access(struct iio_dev *indio_dev, > unsigned reg, unsigned writeval, > unsigned *readval) > @@ -457,12 +554,66 @@ 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); > + > + enable_irq(info->tsirq); > + > + return 0; > +} > + > +static void exynos_adc_ts_close(struct input_dev *dev) > +{ > + struct exynos_adc *info = input_get_drvdata(dev); > + > + disable_irq(info->tsirq); > +} > + > +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; > + > + info->input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); > + info->input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); > + > + input_set_abs_params(info->input, ABS_X, 0, 0x3FF, 0, 0); > + input_set_abs_params(info->input, ABS_Y, 0, 0x3FF, 0, 0); > + > + info->input->name = "S3C24xx TouchScreen"; > + info->input->id.bustype = BUS_HOST; > + 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) > + input_free_device(info->input); > + > + disable_irq(info->tsirq); > + ret = request_threaded_irq(info->tsirq, NULL, exynos_ts_isr, > + 0, "touchscreen", info); > + if (ret) > + input_unregister_device(info->input); > + > + return ret; > +} > + > static int exynos_adc_probe(struct platform_device *pdev) > { > struct exynos_adc *info = NULL; > struct device_node *np = pdev->dev.of_node; > struct iio_dev *indio_dev = NULL; > struct resource *mem; > + bool has_ts = false; > int ret = -ENODEV; > int irq; > > @@ -498,8 +649,14 @@ static int exynos_adc_probe(struct platform_device *pdev) > dev_err(&pdev->dev, "no irq resource?\n"); > return irq; > } > - > info->irq = irq; > + > + irq = platform_get_irq(pdev, 1); > + if (irq == -EPROBE_DEFER) > + return irq; > + > + info->tsirq = irq; > + > info->dev = &pdev->dev; > > init_completion(&info->completion); > @@ -565,6 +722,15 @@ static int exynos_adc_probe(struct platform_device *pdev) > if (info->data->init_hw) > info->data->init_hw(info); > > + /* leave out any TS related code if unreachable */ > + if (IS_BUILTIN(CONFIG_INPUT) || > + (IS_MODULE(CONFIG_INPUT) && config_enabled(MODULE))) This is ugly... We need IS_SUBSYSTEM_AVAILABLE() wrapper for this... Anyway, Acked-by: Dmitry Torokhov > + has_ts = of_property_read_bool(pdev->dev.of_node, "has-touchscreen"); > + if (has_ts) > + ret = exynos_adc_ts_init(info); > + if (ret) > + goto err_iio; > + > ret = of_platform_populate(np, exynos_adc_match, NULL, &indio_dev->dev); > if (ret < 0) { > dev_err(&pdev->dev, "failed adding child nodes\n"); > @@ -576,6 +742,11 @@ static int exynos_adc_probe(struct platform_device *pdev) > err_of_populate: > device_for_each_child(&indio_dev->dev, NULL, > exynos_adc_remove_devices); > + if (has_ts) { > + input_unregister_device(info->input); > + free_irq(info->tsirq, info); > + } > +err_iio: > iio_device_unregister(indio_dev); > err_irq: > free_irq(info->irq, info); > @@ -595,6 +766,11 @@ 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); > > + if (IS_BUILTIN(CONFIG_INPUT) || > + (IS_MODULE(CONFIG_INPUT) && config_enabled(MODULE))) { > + free_irq(info->tsirq, info); > + input_unregister_device(info->input); > + } > device_for_each_child(&indio_dev->dev, NULL, > exynos_adc_remove_devices); > iio_device_unregister(indio_dev); > -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/