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linux-next/drivers/input/touchscreen/bcm_iproc_tsc.c
Raveendra Padasalagi 74813cebd6 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: 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>
2016-04-06 16:11:56 -07:00

532 lines
14 KiB
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/*
* Copyright (C) 2015 Broadcom Corporation
*
* 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/input.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/keyboard.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <asm/irq.h>
#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"
#define PEN_DOWN_STATUS 1
#define PEN_UP_STATUS 0
#define X_MIN 0
#define Y_MIN 0
#define X_MAX 0xFFF
#define Y_MAX 0xFFF
/* Value given by controller for invalid coordinate. */
#define INVALID_COORD 0xFFFFFFFF
/* Register offsets */
#define REGCTL1 0x00
#define REGCTL2 0x04
#define INTERRUPT_THRES 0x08
#define INTERRUPT_MASK 0x0c
#define INTERRUPT_STATUS 0x10
#define CONTROLLER_STATUS 0x14
#define FIFO_DATA 0x18
#define FIFO_DATA_X_Y_MASK 0xFFFF
#define ANALOG_CONTROL 0x1c
#define AUX_DATA 0x20
#define DEBOUNCE_CNTR_STAT 0x24
#define SCAN_CNTR_STAT 0x28
#define REM_CNTR_STAT 0x2c
#define SETTLING_TIMER_STAT 0x30
#define SPARE_REG 0x34
#define SOFT_BYPASS_CONTROL 0x38
#define SOFT_BYPASS_DATA 0x3c
/* Bit values for INTERRUPT_MASK and INTERRUPT_STATUS regs */
#define TS_PEN_INTR_MASK BIT(0)
#define TS_FIFO_INTR_MASK BIT(2)
/* Bit values for CONTROLLER_STATUS reg1 */
#define TS_PEN_DOWN BIT(0)
/* Shift values for control reg1 */
#define SCANNING_PERIOD_SHIFT 24
#define DEBOUNCE_TIMEOUT_SHIFT 16
#define SETTLING_TIMEOUT_SHIFT 8
#define TOUCH_TIMEOUT_SHIFT 0
/* Shift values for coordinates from fifo */
#define X_COORD_SHIFT 0
#define Y_COORD_SHIFT 16
/* Bit values for REGCTL2 */
#define TS_CONTROLLER_EN_BIT BIT(16)
#define TS_CONTROLLER_AVGDATA_SHIFT 8
#define TS_CONTROLLER_AVGDATA_MASK (0x7 << TS_CONTROLLER_AVGDATA_SHIFT)
#define TS_CONTROLLER_PWR_LDO BIT(5)
#define TS_CONTROLLER_PWR_ADC BIT(4)
#define TS_CONTROLLER_PWR_BGP BIT(3)
#define TS_CONTROLLER_PWR_TS BIT(2)
#define TS_WIRE_MODE_BIT BIT(1)
#define dbg_reg(dev, priv, 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 */
u32 scanning_period;
/* Each step is 512 us. Valid 0-255 */
u32 debounce_timeout;
/*
* The settling duration (in ms) is the amount of time the tsc
* waits to allow the voltage to settle after turning on the
* drivers in detection mode. Valid values: 0-11
* 0 = 0.008 ms
* 1 = 0.01 ms
* 2 = 0.02 ms
* 3 = 0.04 ms
* 4 = 0.08 ms
* 5 = 0.16 ms
* 6 = 0.32 ms
* 7 = 0.64 ms
* 8 = 1.28 ms
* 9 = 2.56 ms
* 10 = 5.12 ms
* 11 = 10.24 ms
*/
u32 settling_timeout;
/* touch timeout in sample counts */
u32 touch_timeout;
/*
* Number of data samples which are averaged before a final data point
* is placed into the FIFO
*/
u32 average_data;
/* FIFO threshold */
u32 fifo_threshold;
/* Optional standard touchscreen properties. */
u32 max_x;
u32 max_y;
u32 fuzz_x;
u32 fuzz_y;
bool invert_x;
bool invert_y;
};
struct iproc_ts_priv {
struct platform_device *pdev;
struct input_dev *idev;
struct regmap *regmap;
struct clk *tsc_clk;
int pen_status;
struct tsc_param cfg_params;
};
/*
* Set default values the same as hardware reset values
* except for fifo_threshold with is set to 1.
*/
static const struct tsc_param iproc_default_config = {
.scanning_period = 0x5, /* 1 to 256 */
.debounce_timeout = 0x28, /* 0 to 255 */
.settling_timeout = 0x7, /* 0 to 11 */
.touch_timeout = 0xa, /* 0 to 255 */
.average_data = 5, /* entry 5 = 32 pts */
.fifo_threshold = 1, /* 0 to 31 */
.max_x = X_MAX,
.max_y = Y_MAX,
};
static void ts_reg_dump(struct iproc_ts_priv *priv)
{
struct device *dev = &priv->pdev->dev;
dbg_reg(dev, priv, REGCTL1);
dbg_reg(dev, priv, REGCTL2);
dbg_reg(dev, priv, INTERRUPT_THRES);
dbg_reg(dev, priv, INTERRUPT_MASK);
dbg_reg(dev, priv, INTERRUPT_STATUS);
dbg_reg(dev, priv, CONTROLLER_STATUS);
dbg_reg(dev, priv, FIFO_DATA);
dbg_reg(dev, priv, ANALOG_CONTROL);
dbg_reg(dev, priv, AUX_DATA);
dbg_reg(dev, priv, DEBOUNCE_CNTR_STAT);
dbg_reg(dev, priv, SCAN_CNTR_STAT);
dbg_reg(dev, priv, REM_CNTR_STAT);
dbg_reg(dev, priv, SETTLING_TIMER_STAT);
dbg_reg(dev, priv, SPARE_REG);
dbg_reg(dev, priv, SOFT_BYPASS_CONTROL);
dbg_reg(dev, priv, SOFT_BYPASS_DATA);
}
static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data)
{
struct platform_device *pdev = data;
struct iproc_ts_priv *priv = platform_get_drvdata(pdev);
u32 intr_status;
u32 raw_coordinate;
u16 x;
u16 y;
int i;
bool needs_sync = false;
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 */
regmap_write(priv->regmap, INTERRUPT_STATUS, intr_status);
/* Pen up/down */
if (intr_status & TS_PEN_INTR_MASK) {
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);
needs_sync = true;
dev_dbg(&priv->pdev->dev,
"pen up-down (%d)\n", priv->pen_status);
}
/* coordinates in FIFO exceed the theshold */
if (intr_status & TS_FIFO_INTR_MASK) {
for (i = 0; i < priv->cfg_params.fifo_threshold; i++) {
regmap_read(priv->regmap, FIFO_DATA, &raw_coordinate);
if (raw_coordinate == INVALID_COORD)
continue;
/*
* The x and y coordinate are 16 bits each
* with the x in the lower 16 bits and y in the
* upper 16 bits.
*/
x = (raw_coordinate >> X_COORD_SHIFT) &
FIFO_DATA_X_Y_MASK;
y = (raw_coordinate >> Y_COORD_SHIFT) &
FIFO_DATA_X_Y_MASK;
/* We only want to retain the 12 msb of the 16 */
x = (x >> 4) & 0x0FFF;
y = (y >> 4) & 0x0FFF;
/* Adjust x y according to LCD tsc mount angle. */
if (priv->cfg_params.invert_x)
x = priv->cfg_params.max_x - x;
if (priv->cfg_params.invert_y)
y = priv->cfg_params.max_y - y;
input_report_abs(priv->idev, ABS_X, x);
input_report_abs(priv->idev, ABS_Y, y);
needs_sync = true;
dev_dbg(&priv->pdev->dev, "xy (0x%x 0x%x)\n", x, y);
}
}
if (needs_sync)
input_sync(priv->idev);
return IRQ_HANDLED;
}
static int iproc_ts_start(struct input_dev *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);
if (error) {
dev_err(&priv->pdev->dev, "%s clk_prepare_enable failed %d\n",
__func__, error);
return error;
}
/*
* Interrupt is generated when:
* FIFO reaches the int_th value, and pen event(up/down)
*/
val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, val);
val = priv->cfg_params.fifo_threshold;
regmap_write(priv->regmap, INTERRUPT_THRES, val);
/* Initialize control reg1 */
val = 0;
val |= priv->cfg_params.scanning_period << SCANNING_PERIOD_SHIFT;
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;
regmap_write(priv->regmap, REGCTL1, val);
/* Try to clear all interrupt status */
val = TS_FIFO_INTR_MASK | TS_PEN_INTR_MASK;
regmap_update_bits(priv->regmap, INTERRUPT_STATUS, val, val);
/* Initialize control reg2 */
val = TS_CONTROLLER_EN_BIT | TS_WIRE_MODE_BIT;
val |= priv->cfg_params.average_data << TS_CONTROLLER_AVGDATA_SHIFT;
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 */
mask |= val;
regmap_update_bits(priv->regmap, REGCTL2, mask, val);
ts_reg_dump(priv);
return 0;
}
static void iproc_ts_stop(struct input_dev *dev)
{
u32 val;
struct iproc_ts_priv *priv = input_get_drvdata(dev);
/*
* 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 = TS_CONTROLLER_PWR_TS;
regmap_update_bits(priv->regmap, REGCTL2, val, val);
clk_disable(priv->tsc_clk);
}
static int iproc_get_tsc_config(struct device *dev, struct iproc_ts_priv *priv)
{
struct device_node *np = dev->of_node;
u32 val;
priv->cfg_params = iproc_default_config;
if (!np)
return 0;
if (of_property_read_u32(np, "scanning_period", &val) >= 0) {
if (val < 1 || val > 256) {
dev_err(dev, "scanning_period (%u) must be [1-256]\n",
val);
return -EINVAL;
}
priv->cfg_params.scanning_period = val;
}
if (of_property_read_u32(np, "debounce_timeout", &val) >= 0) {
if (val > 255) {
dev_err(dev, "debounce_timeout (%u) must be [0-255]\n",
val);
return -EINVAL;
}
priv->cfg_params.debounce_timeout = val;
}
if (of_property_read_u32(np, "settling_timeout", &val) >= 0) {
if (val > 11) {
dev_err(dev, "settling_timeout (%u) must be [0-11]\n",
val);
return -EINVAL;
}
priv->cfg_params.settling_timeout = val;
}
if (of_property_read_u32(np, "touch_timeout", &val) >= 0) {
if (val > 255) {
dev_err(dev, "touch_timeout (%u) must be [0-255]\n",
val);
return -EINVAL;
}
priv->cfg_params.touch_timeout = val;
}
if (of_property_read_u32(np, "average_data", &val) >= 0) {
if (val > 8) {
dev_err(dev, "average_data (%u) must be [0-8]\n", val);
return -EINVAL;
}
priv->cfg_params.average_data = val;
}
if (of_property_read_u32(np, "fifo_threshold", &val) >= 0) {
if (val > 31) {
dev_err(dev, "fifo_threshold (%u)) must be [0-31]\n",
val);
return -EINVAL;
}
priv->cfg_params.fifo_threshold = val;
}
/* Parse optional properties. */
of_property_read_u32(np, "touchscreen-size-x", &priv->cfg_params.max_x);
of_property_read_u32(np, "touchscreen-size-y", &priv->cfg_params.max_y);
of_property_read_u32(np, "touchscreen-fuzz-x",
&priv->cfg_params.fuzz_x);
of_property_read_u32(np, "touchscreen-fuzz-y",
&priv->cfg_params.fuzz_y);
priv->cfg_params.invert_x =
of_property_read_bool(np, "touchscreen-inverted-x");
priv->cfg_params.invert_y =
of_property_read_bool(np, "touchscreen-inverted-y");
return 0;
}
static int iproc_ts_probe(struct platform_device *pdev)
{
struct iproc_ts_priv *priv;
struct input_dev *idev;
int irq;
int error;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* 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;
}
priv->tsc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
if (IS_ERR(priv->tsc_clk)) {
error = PTR_ERR(priv->tsc_clk);
dev_err(&pdev->dev,
"failed getting clock tsc_clk: %d\n", error);
return error;
}
priv->pdev = pdev;
error = iproc_get_tsc_config(&pdev->dev, priv);
if (error) {
dev_err(&pdev->dev, "get_tsc_config failed: %d\n", error);
return error;
}
idev = devm_input_allocate_device(&pdev->dev);
if (!idev) {
dev_err(&pdev->dev, "failed to allocate input device\n");
return -ENOMEM;
}
priv->idev = idev;
priv->pen_status = PEN_UP_STATUS;
/* Set input device info */
idev->name = IPROC_TS_NAME;
idev->dev.parent = &pdev->dev;
idev->id.bustype = BUS_HOST;
idev->id.vendor = SERIO_UNKNOWN;
idev->id.product = 0;
idev->id.version = 0;
idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
__set_bit(BTN_TOUCH, idev->keybit);
input_set_abs_params(idev, ABS_X, X_MIN, priv->cfg_params.max_x,
priv->cfg_params.fuzz_x, 0);
input_set_abs_params(idev, ABS_Y, Y_MIN, priv->cfg_params.max_y,
priv->cfg_params.fuzz_y, 0);
idev->open = iproc_ts_start;
idev->close = iproc_ts_stop;
input_set_drvdata(idev, priv);
platform_set_drvdata(pdev, priv);
/* get interrupt */
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "platform_get_irq failed: %d\n", irq);
return irq;
}
error = devm_request_irq(&pdev->dev, irq,
iproc_touchscreen_interrupt,
IRQF_SHARED, IPROC_TS_NAME, pdev);
if (error)
return error;
error = input_register_device(priv->idev);
if (error) {
dev_err(&pdev->dev,
"failed to register input device: %d\n", error);
return error;
}
return 0;
}
static const struct of_device_id iproc_ts_of_match[] = {
{.compatible = "brcm,iproc-touchscreen", },
{ },
};
MODULE_DEVICE_TABLE(of, iproc_ts_of_match);
static struct platform_driver iproc_ts_driver = {
.probe = iproc_ts_probe,
.driver = {
.name = IPROC_TS_NAME,
.of_match_table = of_match_ptr(iproc_ts_of_match),
},
};
module_platform_driver(iproc_ts_driver);
MODULE_DESCRIPTION("IPROC Touchscreen driver");
MODULE_AUTHOR("Broadcom");
MODULE_LICENSE("GPL v2");
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