Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 74813ceb authored by Raveendra Padasalagi's avatar Raveendra Padasalagi Committed by Dmitry Torokhov
Browse files

Input: bcm_iproc_tsc - use syscon to access shared registers 



In Cygnus SOC touch screen controller registers are shared with ADC and
flex timer. Using readl/writel could lead to race condition. So touch
screen driver is enhanced to support register access using syscon framework
API's to take care of mutually exclusive access.

Signed-off-by: default avatarRaveendra Padasalagi <raveendra.padasalagi@broadcom.com>
Reviewed-by: default avatarRay Jui <ray.jui@broadcom.com>
Reviewed-by: default avatarScott Branden <scott.branden@broadcom.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 20aa787e

Documentation/devicetree/bindings/input/touchscreen/brcm,iproc-touchscreen.txt

+16 −5
Original line number Diff line number Diff line
@@ -2,11 +2,17 @@ 


Required properties:

- compatible: must be "brcm,iproc-touchscreen"

- reg: physical base address of the controller and length of memory mapped

  region.

- ts_syscon: handler of syscon node defining physical base

  address of the controller and length of memory mapped region.

  If this property is selected please make sure MFD_SYSCON config

  is enabled in the defconfig file.

- clocks:  The clock provided by the SOC to driver the tsc

- clock-name:  name for the clock

- interrupts: The touchscreen controller's interrupt

- address-cells: Specify the number of u32 entries needed in child nodes.

  Should set to 1.

- size-cells: Specify number of u32 entries needed to specify child nodes size

  in reg property. Should set to 1.



Optional properties:

- scanning_period: Time between scans. Each step is 1024 us.  Valid 1-256.
@@ -53,13 +59,18 @@ Optional properties: 
- touchscreen-inverted-x: X axis is inverted (boolean)

- touchscreen-inverted-y: Y axis is inverted (boolean)



Example:

Example: An example of touchscreen node



	touchscreen: tsc@0x180A6000 {

	ts_adc_syscon: ts_adc_syscon@180a6000 {

		compatible = "brcm,iproc-ts-adc-syscon","syscon";

		reg = <0x180a6000 0xc30>;

	};



	touchscreen: touchscreen@180A6000 {

		compatible = "brcm,iproc-touchscreen";

		#address-cells = <1>;

		#size-cells = <1>;

		reg = <0x180A6000 0x40>;

		ts_syscon = <&ts_adc_syscon>;

		clocks = <&adc_clk>;

		clock-names = "tsc_clk";

		interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;

arch/arm/boot/dts/bcm-cygnus.dtsi

+9 −2
Original line number Diff line number Diff line
@@ -351,9 +351,16 @@ 
					<&pinctrl 142 10 1>;

		};



		touchscreen: tsc@180a6000 {

		ts_adc_syscon: ts_adc_syscon@180a6000 {

			compatible = "brcm,iproc-ts-adc-syscon", "syscon";

			reg = <0x180a6000 0xc30>;

		};



		touchscreen: touchscreen@180a6000 {

			compatible = "brcm,iproc-touchscreen";

			reg = <0x180a6000 0x40>;

			#address-cells = <1>;

			#size-cells = <1>;

			ts_syscon = <&ts_adc_syscon>;

			clocks = <&asiu_clks BCM_CYGNUS_ASIU_ADC_CLK>;

			clock-names = "tsc_clk";

			interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;

drivers/input/touchscreen/bcm_iproc_tsc.c

+43 −34
Original line number Diff line number Diff line
@@ -23,6 +23,8 @@ 
#include <linux/io.h>

#include <linux/clk.h>

#include <linux/serio.h>

#include <linux/mfd/syscon.h>

#include <linux/regmap.h>



#define IPROC_TS_NAME "iproc-ts"
@@ -88,7 +90,11 @@ 
#define TS_WIRE_MODE_BIT        BIT(1)



#define dbg_reg(dev, priv, reg) \

	dev_dbg(dev, "%20s= 0x%08x\n", #reg, readl((priv)->regs + reg))

do { \

	u32 val; \

	regmap_read(priv->regmap, reg, &val); \

	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \

} while (0)



struct tsc_param {

	/* Each step is 1024 us.  Valid 1-256 */
@@ -141,7 +147,7 @@ struct iproc_ts_priv { 
	struct platform_device *pdev;

	struct input_dev *idev;



	void __iomem *regs;

	struct regmap *regmap;

	struct clk *tsc_clk;



	int  pen_status;
@@ -196,17 +202,17 @@ static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data) 
	int i;

	bool needs_sync = false;



	intr_status = readl(priv->regs + INTERRUPT_STATUS);

	regmap_read(priv->regmap, INTERRUPT_STATUS, &intr_status);

	intr_status &= TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;

	if (intr_status == 0)

		return IRQ_NONE;



	/* Clear all interrupt status bits, write-1-clear */

	writel(intr_status, priv->regs + INTERRUPT_STATUS);



	regmap_write(priv->regmap, INTERRUPT_STATUS, intr_status);

	/* Pen up/down */

	if (intr_status & TS_PEN_INTR_MASK) {

		if (readl(priv->regs + CONTROLLER_STATUS) & TS_PEN_DOWN)

		regmap_read(priv->regmap, CONTROLLER_STATUS, &priv->pen_status);

		if (priv->pen_status & TS_PEN_DOWN)

			priv->pen_status = PEN_DOWN_STATUS;

		else

			priv->pen_status = PEN_UP_STATUS;
@@ -221,7 +227,7 @@ static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data) 
	/* coordinates in FIFO exceed the theshold */

	if (intr_status & TS_FIFO_INTR_MASK) {

		for (i = 0; i < priv->cfg_params.fifo_threshold; i++) {

			raw_coordinate = readl(priv->regs + FIFO_DATA);

			regmap_read(priv->regmap, FIFO_DATA, &raw_coordinate);

			if (raw_coordinate == INVALID_COORD)

				continue;
@@ -239,7 +245,7 @@ static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data) 
			x = (x >> 4) & 0x0FFF;

			y = (y >> 4) & 0x0FFF;



			/* adjust x y according to lcd tsc mount angle */

			/* Adjust x y according to LCD tsc mount angle. */

			if (priv->cfg_params.invert_x)

				x = priv->cfg_params.max_x - x;
@@ -262,9 +268,10 @@ static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data) 


static int iproc_ts_start(struct input_dev *idev)

{

	struct iproc_ts_priv *priv = input_get_drvdata(idev);

	u32 val;

	u32 mask;

	int error;

	struct iproc_ts_priv *priv = input_get_drvdata(idev);



	/* Enable clock */

	error = clk_prepare_enable(priv->tsc_clk);
@@ -279,9 +286,10 @@ static int iproc_ts_start(struct input_dev *idev) 
	 *  FIFO reaches the int_th value, and pen event(up/down)

	 */

	val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;

	writel(val, priv->regs + INTERRUPT_MASK);

	regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, val);



	writel(priv->cfg_params.fifo_threshold, priv->regs + INTERRUPT_THRES);

	val = priv->cfg_params.fifo_threshold;

	regmap_write(priv->regmap, INTERRUPT_THRES, val);



	/* Initialize control reg1 */

	val = 0;
@@ -289,26 +297,23 @@ static int iproc_ts_start(struct input_dev *idev) 
	val |= priv->cfg_params.debounce_timeout << DEBOUNCE_TIMEOUT_SHIFT;

	val |= priv->cfg_params.settling_timeout << SETTLING_TIMEOUT_SHIFT;

	val |= priv->cfg_params.touch_timeout << TOUCH_TIMEOUT_SHIFT;

	writel(val, priv->regs + REGCTL1);

	regmap_write(priv->regmap, REGCTL1, val);



	/* Try to clear all interrupt status */

	val = readl(priv->regs + INTERRUPT_STATUS);

	val |= TS_FIFO_INTR_MASK | TS_PEN_INTR_MASK;

	writel(val, priv->regs + INTERRUPT_STATUS);

	val = TS_FIFO_INTR_MASK | TS_PEN_INTR_MASK;

	regmap_update_bits(priv->regmap, INTERRUPT_STATUS, val, val);



	/* Initialize control reg2 */

	val = readl(priv->regs + REGCTL2);

	val |= TS_CONTROLLER_EN_BIT | TS_WIRE_MODE_BIT;



	val &= ~TS_CONTROLLER_AVGDATA_MASK;

	val = TS_CONTROLLER_EN_BIT | TS_WIRE_MODE_BIT;

	val |= priv->cfg_params.average_data << TS_CONTROLLER_AVGDATA_SHIFT;



	val &= ~(TS_CONTROLLER_PWR_LDO |	/* PWR up LDO */

	mask = (TS_CONTROLLER_AVGDATA_MASK);

	mask |= (TS_CONTROLLER_PWR_LDO |	/* PWR up LDO */

		   TS_CONTROLLER_PWR_ADC |	/* PWR up ADC */

		   TS_CONTROLLER_PWR_BGP |	/* PWR up BGP */

		   TS_CONTROLLER_PWR_TS);	/* PWR up TS */



	writel(val, priv->regs + REGCTL2);

	mask |= val;

	regmap_update_bits(priv->regmap, REGCTL2, mask, val);



	ts_reg_dump(priv);
@@ -320,12 +325,17 @@ static void iproc_ts_stop(struct input_dev *dev) 
	u32 val;

	struct iproc_ts_priv *priv = input_get_drvdata(dev);



	writel(0, priv->regs + INTERRUPT_MASK); /* Disable all interrupts */

	/*

	 * Disable FIFO int_th and pen event(up/down)Interrupts only

	 * as the interrupt mask register is shared between ADC, TS and

	 * flextimer.

	 */

	val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;

	regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, 0);



	/* Only power down touch screen controller */

	val = readl(priv->regs + REGCTL2);

	val |= TS_CONTROLLER_PWR_TS;

	writel(val, priv->regs + REGCTL2);

	val = TS_CONTROLLER_PWR_TS;

	regmap_update_bits(priv->regmap, REGCTL2, val, val);



	clk_disable(priv->tsc_clk);

}
@@ -414,7 +424,6 @@ static int iproc_ts_probe(struct platform_device *pdev) 
{

	struct iproc_ts_priv *priv;

	struct input_dev *idev;

	struct resource *res;

	int irq;

	int error;
@@ -422,11 +431,11 @@ static int iproc_ts_probe(struct platform_device *pdev) 
	if (!priv)

		return -ENOMEM;



	/* touchscreen controller memory mapped regs */

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	priv->regs = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(priv->regs)) {

		error = PTR_ERR(priv->regs);

	/* touchscreen controller memory mapped regs via syscon*/

	priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,

							"ts_syscon");

	if (IS_ERR(priv->regmap)) {

		error = PTR_ERR(priv->regmap);

		dev_err(&pdev->dev, "unable to map I/O memory:%d\n", error);

		return error;

	}