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Input: bcm_iproc_tsc - use syscon to access shared registers

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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: Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Raveendra Padasalagi 2016-04-06 10:26:27 -07:00 committed by Dmitry Torokhov
parent 20aa787e45
commit 74813cebd6
3 changed files with 68 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
Documentation/devicetree/bindings/input/touchscreen/brcm,iproc-touchscreen.txt
View File

@ -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>;

11
arch/arm/boot/dts/bcm-cygnus.dtsi
View File

@ -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>;

77
drivers/input/touchscreen/bcm_iproc_tsc.c
View File

@ -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;
@ -196,22 +202,22 @@ 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;
input_report_key(priv->idev, BTN_TOUCH, priv->pen_status);
input_report_key(priv->idev, BTN_TOUCH, priv->pen_status);
needs_sync = true;
dev_dbg(&priv->pdev->dev,
@ -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;
@ -422,12 +431,12 @@ 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);
dev_err(&pdev->dev, "unable to map I/O memory: %d\n", error);
/* 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;
}