/*
* TI Touch Screen / ADC MFD driver
*
* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
*
* 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/slab.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/regmap.h>
#include <linux/mfd/core.h>
#include <linux/pm_runtime.h>
#include <linux/mfd/ti_am335x_tscadc.h>
#include <linux/input/ti_am335x_tsc.h>
#include <linux/platform_data/ti_am335x_adc.h>
static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
{
unsigned int val;
regmap_read(tsadc->regmap_tscadc, reg, &val);
return val;
}
static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
unsigned int val)
{
regmap_write(tsadc->regmap_tscadc, reg, val);
}
static const struct regmap_config tscadc_regmap_config = {
.name = "ti_tscadc",
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
};
static void tscadc_idle_config(struct ti_tscadc_dev *config)
{
unsigned int idleconfig;
idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
tscadc_writel(config, REG_IDLECONFIG, idleconfig);
}
static int ti_tscadc_probe(struct platform_device *pdev)
{
struct ti_tscadc_dev *tscadc;
struct resource *res;
struct clk *clk;
struct mfd_tscadc_board *pdata = pdev->dev.platform_data;
struct mfd_cell *cell;
int err, ctrl;
int clk_value, clock_rate;
int tsc_wires, adc_channels = 0, total_channels;
if (!pdata) {
dev_err(&pdev->dev, "Could not find platform data\n");
return -EINVAL;
}
if (pdata->adc_init)
adc_channels = pdata->adc_init->adc_channels;
tsc_wires = pdata->tsc_init->wires;
total_channels = tsc_wires + adc_channels;
if (total_channels > 8) {
dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
return -EINVAL;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "no memory resource defined.\n");
return -EINVAL;
}
/* Allocate memory for device */
tscadc = devm_kzalloc(&pdev->dev,
sizeof(struct ti_tscadc_dev), GFP_KERNEL);
if (!tscadc) {
dev_err(&pdev->dev, "failed to allocate memory.\n");
return -ENOMEM;
}
tscadc->dev = &pdev->dev;
err = platform_get_irq(pdev, 0);
if (err < 0) {
dev_err(&pdev->dev, "no irq ID is specified.\n");
goto ret;
} else
tscadc->irq = err;
res = devm_request_mem_region(&pdev->dev,
res->start, resource_size(res), pdev->name);
if (!res) {
dev_err(&pdev->dev, "failed to reserve registers.\n");
return -EBUSY;
}
tscadc->tscadc_base = devm_ioremap(&pdev->dev,
res->start, resource_size(res));
if (!tscadc->tscadc_base) {
dev_err(&pdev->dev, "failed to map registers.\n");
return -ENOMEM;
}
tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
tscadc->tscadc_base, &tscadc_regmap_config);
if (IS_ERR(tscadc->regmap_tscadc)) {
dev_err(&pdev->dev, "regmap init failed\n");
err = PTR_ERR(tscadc->regmap_tscadc);
goto ret;
}
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
/*
* The TSC_ADC_Subsystem has 2 clock domains
* OCP_CLK and ADC_CLK.
* The ADC clock is expected to run at target of 3MHz,
* and expected to capture 12-bit data at a rate of 200 KSPS.
* The TSC_ADC_SS controller design assumes the OCP clock is
* at least 6x faster than the ADC clock.
*/
clk = clk_get(&pdev->dev, "adc_tsc_fck");
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "failed to get TSC fck\n");
err = PTR_ERR(clk);
goto err_disable_clk;
}
clock_rate = clk_get_rate(clk);
clk_put(clk);
clk_value = clock_rate / ADC_CLK;
if (clk_value < MAX_CLK_DIV) {
dev_err(&pdev->dev, "clock input less than min clock requirement\n");
err = -EINVAL;
goto err_disable_clk;
}
/* TSCADC_CLKDIV needs to be configured to the value minus 1 */
clk_value = clk_value - 1;
tscadc_writel(tscadc, REG_CLKDIV, clk_value);
/* Set the control register bits */
ctrl = CNTRLREG_STEPCONFIGWRT |
CNTRLREG_TSCENB |
CNTRLREG_STEPID |
CNTRLREG_4WIRE;
tscadc_writel(tscadc, REG_CTRL, ctrl);
/* Set register bits for Idle Config Mode */
tscadc_idle_config(tscadc);
/* Enable the TSC module enable bit */
ctrl = tscadc_readl(tscadc, REG_CTRL);
ctrl |= CNTRLREG_TSCSSENB;
tscadc_writel(tscadc, REG_CTRL, ctrl);
/* TSC Cell */
cell = &tscadc->cells[TSC_CELL];
cell->name = "tsc";
cell->platform_data = tscadc;
cell->pdata_size = sizeof(*tscadc);
/* ADC Cell */
cell = &tscadc->cells[ADC_CELL];
cell->name = "tiadc";
cell->platform_data = tscadc;
cell->pdata_size = sizeof(*tscadc);
err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
TSCADC_CELLS, NULL, 0, NULL);
if (err < 0)
goto err_disable_clk;
device_init_wakeup(&pdev->dev, true);
platform_set_drvdata(pdev, tscadc);
return 0;
err_disable_clk:
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
ret:
return err;
}
static int ti_tscadc_remove(struct platform_device *pdev)
{
struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev);
tscadc_writel(tscadc, REG_SE, 0x00);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
mfd_remove_devices(tscadc->dev);
return 0;
}
#ifdef CONFIG_PM
static int tscadc_suspend(struct device *dev)
{
struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);
tscadc_writel(tscadc_dev, REG_SE, 0x00);
pm_runtime_put_sync(dev);
return 0;
}
static int tscadc_resume(struct device *dev)
{
struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);
unsigned int restore, ctrl;
pm_runtime_get_sync(dev);
/* context restore */
ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB |
CNTRLREG_STEPID | CNTRLREG_4WIRE;
tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
tscadc_idle_config(tscadc_dev);
tscadc_writel(tscadc_dev, REG_SE, STPENB_STEPENB);
restore = tscadc_readl(tscadc_dev, REG_CTRL);
tscadc_writel(tscadc_dev, REG_CTRL,
(restore | CNTRLREG_TSCSSENB));
return 0;
}
static const struct dev_pm_ops tscadc_pm_ops = {
.suspend = tscadc_suspend,
.resume = tscadc_resume,
};
#define TSCADC_PM_OPS (&tscadc_pm_ops)
#else
#define TSCADC_PM_OPS NULL
#endif
static struct platform_driver ti_tscadc_driver = {
.driver = {
.name = "ti_tscadc",
.owner = THIS_MODULE,
.pm = TSCADC_PM_OPS,
},
.probe = ti_tscadc_probe,
.remove = ti_tscadc_remove,
};
module_platform_driver(ti_tscadc_driver);
MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
MODULE_LICENSE("GPL");
