linuxdebug/drivers/mfd/ti_am335x_tscadc.c

394 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* TI Touch Screen / ADC MFD driver
*
* Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com/
*/
#include <linux/module.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/of.h>
#include <linux/of_device.h>
#include <linux/sched.h>
#include <linux/mfd/ti_am335x_tscadc.h>
static const struct regmap_config tscadc_regmap_config = {
.name = "ti_tscadc",
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
};
void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tscadc, u32 val)
{
unsigned long flags;
spin_lock_irqsave(&tscadc->reg_lock, flags);
tscadc->reg_se_cache |= val;
if (tscadc->adc_waiting)
wake_up(&tscadc->reg_se_wait);
else if (!tscadc->adc_in_use)
regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
spin_unlock_irqrestore(&tscadc->reg_lock, flags);
}
EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);
static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tscadc)
{
DEFINE_WAIT(wait);
u32 reg;
regmap_read(tscadc->regmap, REG_ADCFSM, &reg);
if (reg & SEQ_STATUS) {
tscadc->adc_waiting = true;
prepare_to_wait(&tscadc->reg_se_wait, &wait,
TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&tscadc->reg_lock);
schedule();
spin_lock_irq(&tscadc->reg_lock);
finish_wait(&tscadc->reg_se_wait, &wait);
/*
* Sequencer should either be idle or
* busy applying the charge step.
*/
regmap_read(tscadc->regmap, REG_ADCFSM, &reg);
WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP));
tscadc->adc_waiting = false;
}
tscadc->adc_in_use = true;
}
void am335x_tsc_se_set_once(struct ti_tscadc_dev *tscadc, u32 val)
{
spin_lock_irq(&tscadc->reg_lock);
am335x_tscadc_need_adc(tscadc);
regmap_write(tscadc->regmap, REG_SE, val);
spin_unlock_irq(&tscadc->reg_lock);
}
EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);
void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tscadc)
{
unsigned long flags;
spin_lock_irqsave(&tscadc->reg_lock, flags);
tscadc->adc_in_use = false;
regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
spin_unlock_irqrestore(&tscadc->reg_lock, flags);
}
EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);
void am335x_tsc_se_clr(struct ti_tscadc_dev *tscadc, u32 val)
{
unsigned long flags;
spin_lock_irqsave(&tscadc->reg_lock, flags);
tscadc->reg_se_cache &= ~val;
regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
spin_unlock_irqrestore(&tscadc->reg_lock, flags);
}
EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
static void tscadc_idle_config(struct ti_tscadc_dev *tscadc)
{
unsigned int idleconfig;
idleconfig = STEPCONFIG_INM_ADCREFM | STEPCONFIG_INP_ADCREFM;
if (ti_adc_with_touchscreen(tscadc))
idleconfig |= STEPCONFIG_YNN | STEPCONFIG_YPN;
regmap_write(tscadc->regmap, REG_IDLECONFIG, idleconfig);
}
static int ti_tscadc_probe(struct platform_device *pdev)
{
struct ti_tscadc_dev *tscadc;
struct resource *res;
struct clk *clk;
struct device_node *node;
struct mfd_cell *cell;
struct property *prop;
const __be32 *cur;
bool use_tsc = false, use_mag = false;
u32 val;
int err;
int tscmag_wires = 0, adc_channels = 0, cell_idx = 0, total_channels;
int readouts = 0, mag_tracks = 0;
/* Allocate memory for device */
tscadc = devm_kzalloc(&pdev->dev, sizeof(*tscadc), GFP_KERNEL);
if (!tscadc)
return -ENOMEM;
tscadc->dev = &pdev->dev;
if (!pdev->dev.of_node) {
dev_err(&pdev->dev, "Could not find valid DT data.\n");
return -EINVAL;
}
tscadc->data = of_device_get_match_data(&pdev->dev);
if (ti_adc_with_touchscreen(tscadc)) {
node = of_get_child_by_name(pdev->dev.of_node, "tsc");
of_property_read_u32(node, "ti,wires", &tscmag_wires);
err = of_property_read_u32(node, "ti,coordinate-readouts",
&readouts);
if (err < 0)
of_property_read_u32(node, "ti,coordiante-readouts",
&readouts);
of_node_put(node);
if (tscmag_wires)
use_tsc = true;
} else {
/*
* When adding support for the magnetic stripe reader, here is
* the place to look for the number of tracks used from device
* tree. Let's default to 0 for now.
*/
mag_tracks = 0;
tscmag_wires = mag_tracks * 2;
if (tscmag_wires)
use_mag = true;
}
node = of_get_child_by_name(pdev->dev.of_node, "adc");
of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
adc_channels++;
if (val > 7) {
dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
val);
of_node_put(node);
return -EINVAL;
}
}
of_node_put(node);
total_channels = tscmag_wires + adc_channels;
if (total_channels > 8) {
dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
return -EINVAL;
}
if (total_channels == 0) {
dev_err(&pdev->dev, "Need at least one channel.\n");
return -EINVAL;
}
if (use_tsc && (readouts * 2 + 2 + adc_channels > 16)) {
dev_err(&pdev->dev, "Too many step configurations requested\n");
return -EINVAL;
}
err = platform_get_irq(pdev, 0);
if (err < 0)
return err;
else
tscadc->irq = err;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
tscadc->tscadc_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(tscadc->tscadc_base))
return PTR_ERR(tscadc->tscadc_base);
tscadc->tscadc_phys_base = res->start;
tscadc->regmap = devm_regmap_init_mmio(&pdev->dev,
tscadc->tscadc_base,
&tscadc_regmap_config);
if (IS_ERR(tscadc->regmap)) {
dev_err(&pdev->dev, "regmap init failed\n");
return PTR_ERR(tscadc->regmap);
}
spin_lock_init(&tscadc->reg_lock);
init_waitqueue_head(&tscadc->reg_se_wait);
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
/*
* The TSC_ADC_Subsystem has 2 clock domains: OCP_CLK and ADC_CLK.
* ADCs produce a 12-bit sample every 15 ADC_CLK cycles.
* am33xx ADCs expect to capture 200ksps.
* am47xx ADCs expect to capture 867ksps.
* We need ADC clocks respectively running at 3MHz and 13MHz.
* These frequencies are valid since TSC_ADC_SS controller design
* assumes the OCP clock is at least 6x faster than the ADC clock.
*/
clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "failed to get fck\n");
err = PTR_ERR(clk);
goto err_disable_clk;
}
tscadc->clk_div = (clk_get_rate(clk) / tscadc->data->target_clk_rate) - 1;
regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div);
/*
* Set the control register bits. tscadc->ctrl stores the configuration
* of the CTRL register but not the subsystem enable bit which must be
* added manually when timely.
*/
tscadc->ctrl = CNTRLREG_STEPID;
if (ti_adc_with_touchscreen(tscadc)) {
tscadc->ctrl |= CNTRLREG_TSC_STEPCONFIGWRT;
if (use_tsc) {
tscadc->ctrl |= CNTRLREG_TSC_ENB;
if (tscmag_wires == 5)
tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
else
tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
}
} else {
tscadc->ctrl |= CNTRLREG_MAG_PREAMP_PWRDOWN |
CNTRLREG_MAG_PREAMP_BYPASS;
}
regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
tscadc_idle_config(tscadc);
/* Enable the TSC module enable bit */
regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB);
/* TSC or MAG Cell */
if (use_tsc || use_mag) {
cell = &tscadc->cells[cell_idx++];
cell->name = tscadc->data->secondary_feature_name;
cell->of_compatible = tscadc->data->secondary_feature_compatible;
cell->platform_data = &tscadc;
cell->pdata_size = sizeof(tscadc);
}
/* ADC Cell */
if (adc_channels > 0) {
cell = &tscadc->cells[cell_idx++];
cell->name = tscadc->data->adc_feature_name;
cell->of_compatible = tscadc->data->adc_feature_compatible;
cell->platform_data = &tscadc;
cell->pdata_size = sizeof(tscadc);
}
err = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
tscadc->cells, cell_idx, NULL, 0, NULL);
if (err < 0)
goto err_disable_clk;
platform_set_drvdata(pdev, tscadc);
return 0;
err_disable_clk:
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return err;
}
static int ti_tscadc_remove(struct platform_device *pdev)
{
struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev);
regmap_write(tscadc->regmap, REG_SE, 0x00);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
mfd_remove_devices(tscadc->dev);
return 0;
}
static int __maybe_unused ti_tscadc_can_wakeup(struct device *dev, void *data)
{
return device_may_wakeup(dev);
}
static int __maybe_unused tscadc_suspend(struct device *dev)
{
struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev);
regmap_write(tscadc->regmap, REG_SE, 0x00);
if (device_for_each_child(dev, NULL, ti_tscadc_can_wakeup)) {
u32 ctrl;
regmap_read(tscadc->regmap, REG_CTRL, &ctrl);
ctrl &= ~(CNTRLREG_POWERDOWN);
ctrl |= CNTRLREG_SSENB;
regmap_write(tscadc->regmap, REG_CTRL, ctrl);
}
pm_runtime_put_sync(dev);
return 0;
}
static int __maybe_unused tscadc_resume(struct device *dev)
{
struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev);
pm_runtime_get_sync(dev);
regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div);
regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
tscadc_idle_config(tscadc);
regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB);
return 0;
}
static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume);
static const struct ti_tscadc_data tscdata = {
.adc_feature_name = "TI-am335x-adc",
.adc_feature_compatible = "ti,am3359-adc",
.secondary_feature_name = "TI-am335x-tsc",
.secondary_feature_compatible = "ti,am3359-tsc",
.target_clk_rate = TSC_ADC_CLK,
};
static const struct ti_tscadc_data magdata = {
.adc_feature_name = "TI-am43xx-adc",
.adc_feature_compatible = "ti,am4372-adc",
.secondary_feature_name = "TI-am43xx-mag",
.secondary_feature_compatible = "ti,am4372-mag",
.target_clk_rate = MAG_ADC_CLK,
};
static const struct of_device_id ti_tscadc_dt_ids[] = {
{ .compatible = "ti,am3359-tscadc", .data = &tscdata },
{ .compatible = "ti,am4372-magadc", .data = &magdata },
{ }
};
MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
static struct platform_driver ti_tscadc_driver = {
.driver = {
.name = "ti_am3359-tscadc",
.pm = &tscadc_pm_ops,
.of_match_table = ti_tscadc_dt_ids,
},
.probe = ti_tscadc_probe,
.remove = ti_tscadc_remove,
};
module_platform_driver(ti_tscadc_driver);
MODULE_DESCRIPTION("TI touchscreen/magnetic stripe reader/ADC MFD controller driver");
MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
MODULE_LICENSE("GPL");