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// SPDX-License-Identifier: GPL-1.0+
//
// Copyright (c) 2008 Simtec Electronics
// http://armlinux.simtec.co.uk/
// Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
//
// Samsung ADC device core
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/regulator/consumer.h>
#include <plat/regs-adc.h>
#include <plat/adc.h>
/* This driver is designed to control the usage of the ADC block between
* the touchscreen and any other drivers that may need to use it, such as
* the hwmon driver.
*
* Priority will be given to the touchscreen driver, but as this itself is
* rate limited it should not starve other requests which are processed in
* order that they are received.
*
* Each user registers to get a client block which uniquely identifies it
* and stores information such as the necessary functions to callback when
* action is required.
*/
enum s3c_cpu_type {
TYPE_ADCV1, /* S3C24XX */
TYPE_ADCV11, /* S3C2443 */
TYPE_ADCV12, /* S3C2416, S3C2450 */
TYPE_ADCV2, /* S3C64XX */
TYPE_ADCV3, /* S5PV210, S5PC110, EXYNOS4210 */
};
struct s3c_adc_client {
struct platform_device *pdev;
struct list_head pend;
wait_queue_head_t *wait;
unsigned int nr_samples;
int result;
unsigned char is_ts;
unsigned char channel;
void (*select_cb)(struct s3c_adc_client *c, unsigned selected);
void (*convert_cb)(struct s3c_adc_client *c,
unsigned val1, unsigned val2,
unsigned *samples_left);
};
struct adc_device {
struct platform_device *pdev;
struct platform_device *owner;
struct clk *clk;
struct s3c_adc_client *cur;
struct s3c_adc_client *ts_pend;
void __iomem *regs;
spinlock_t lock;
unsigned int prescale;
int irq;
struct regulator *vdd;
};
static struct adc_device *adc_dev;
static LIST_HEAD(adc_pending); /* protected by adc_device.lock */
#define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)
static inline void s3c_adc_convert(struct adc_device *adc)
{
unsigned con = readl(adc->regs + S3C2410_ADCCON);
con |= S3C2410_ADCCON_ENABLE_START;
writel(con, adc->regs + S3C2410_ADCCON);
}
static inline void s3c_adc_select(struct adc_device *adc,
struct s3c_adc_client *client)
{
unsigned con = readl(adc->regs + S3C2410_ADCCON);
enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
client->select_cb(client, 1);
if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV2)
con &= ~S3C2410_ADCCON_MUXMASK;
con &= ~S3C2410_ADCCON_STDBM;
con &= ~S3C2410_ADCCON_STARTMASK;
if (!client->is_ts) {
if (cpu == TYPE_ADCV3)
writel(client->channel & 0xf, adc->regs + S5P_ADCMUX);
else if (cpu == TYPE_ADCV11 || cpu == TYPE_ADCV12)
writel(client->channel & 0xf,
adc->regs + S3C2443_ADCMUX);
else
con |= S3C2410_ADCCON_SELMUX(client->channel);
}
writel(con, adc->regs + S3C2410_ADCCON);
}
static void s3c_adc_dbgshow(struct adc_device *adc)
{
adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",
readl(adc->regs + S3C2410_ADCCON),
readl(adc->regs + S3C2410_ADCTSC),
readl(adc->regs + S3C2410_ADCDLY));
}
static void s3c_adc_try(struct adc_device *adc)
{
struct s3c_adc_client *next = adc->ts_pend;
if (!next && !list_empty(&adc_pending)) {
next = list_first_entry(&adc_pending,
struct s3c_adc_client, pend);
list_del(&next->pend);
} else
adc->ts_pend = NULL;
if (next) {
adc_dbg(adc, "new client is %p\n", next);
adc->cur = next;
s3c_adc_select(adc, next);
s3c_adc_convert(adc);
s3c_adc_dbgshow(adc);
}
}
int s3c_adc_start(struct s3c_adc_client *client,
unsigned int channel, unsigned int nr_samples)
{
struct adc_device *adc = adc_dev;
unsigned long flags;
if (!adc) {
printk(KERN_ERR "%s: failed to find adc\n", __func__);
return -EINVAL;
}
spin_lock_irqsave(&adc->lock, flags);
if (client->is_ts && adc->ts_pend) {
spin_unlock_irqrestore(&adc->lock, flags);
return -EAGAIN;
}
client->channel = channel;
client->nr_samples = nr_samples;
if (client->is_ts)
adc->ts_pend = client;
else
list_add_tail(&client->pend, &adc_pending);
if (!adc->cur)
s3c_adc_try(adc);
spin_unlock_irqrestore(&adc->lock, flags);
return 0;
}
EXPORT_SYMBOL_GPL(s3c_adc_start);
static void s3c_convert_done(struct s3c_adc_client *client,
unsigned v, unsigned u, unsigned *left)
{
client->result = v;
wake_up(client->wait);
}
int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
{
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
int ret;
client->convert_cb = s3c_convert_done;
client->wait = &wake;
client->result = -1;
ret = s3c_adc_start(client, ch, 1);
if (ret < 0)
goto err;
ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
if (client->result < 0) {
ret = -ETIMEDOUT;
goto err;
}
client->convert_cb = NULL;
return client->result;
err:
return ret;
}
EXPORT_SYMBOL_GPL(s3c_adc_read);
static void s3c_adc_default_select(struct s3c_adc_client *client,
unsigned select)
{
}
struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
void (*select)(struct s3c_adc_client *client,
unsigned int selected),
void (*conv)(struct s3c_adc_client *client,
unsigned d0, unsigned d1,
unsigned *samples_left),
unsigned int is_ts)
{
struct s3c_adc_client *client;
WARN_ON(!pdev);
if (!select)
select = s3c_adc_default_select;
if (!pdev)
return ERR_PTR(-EINVAL);
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (!client)
return ERR_PTR(-ENOMEM);
client->pdev = pdev;
client->is_ts = is_ts;
client->select_cb = select;
client->convert_cb = conv;
return client;
}
EXPORT_SYMBOL_GPL(s3c_adc_register);
void s3c_adc_release(struct s3c_adc_client *client)
{
unsigned long flags;
spin_lock_irqsave(&adc_dev->lock, flags);
/* We should really check that nothing is in progress. */
if (adc_dev->cur == client)
adc_dev->cur = NULL;
if (adc_dev->ts_pend == client)
adc_dev->ts_pend = NULL;
else {
struct list_head *p, *n;
struct s3c_adc_client *tmp;
list_for_each_safe(p, n, &adc_pending) {
tmp = list_entry(p, struct s3c_adc_client, pend);
if (tmp == client)
list_del(&tmp->pend);
}
}
if (adc_dev->cur == NULL)
s3c_adc_try(adc_dev);
spin_unlock_irqrestore(&adc_dev->lock, flags);
kfree(client);
}
EXPORT_SYMBOL_GPL(s3c_adc_release);
static irqreturn_t s3c_adc_irq(int irq, void *pw)
{
struct adc_device *adc = pw;
struct s3c_adc_client *client = adc->cur;
enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;
unsigned data0, data1;
if (!client) {
dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
goto exit;
}
data0 = readl(adc->regs + S3C2410_ADCDAT0);
data1 = readl(adc->regs + S3C2410_ADCDAT1);
adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
client->nr_samples--;
if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV11) {
data0 &= 0x3ff;
data1 &= 0x3ff;
} else {
/* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */
data0 &= 0xfff;
data1 &= 0xfff;
}
if (client->convert_cb)
(client->convert_cb)(client, data0, data1, &client->nr_samples);
if (client->nr_samples > 0) {
/* fire another conversion for this */
client->select_cb(client, 1);
s3c_adc_convert(adc);
} else {
spin_lock(&adc->lock);
(client->select_cb)(client, 0);
adc->cur = NULL;
s3c_adc_try(adc);
spin_unlock(&adc->lock);
}
exit:
if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) {
/* Clear ADC interrupt */
writel(0, adc->regs + S3C64XX_ADCCLRINT);
}
return IRQ_HANDLED;
}
static int s3c_adc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct adc_device *adc;
struct resource *regs;
enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
int ret;
unsigned tmp;
adc = devm_kzalloc(dev, sizeof(*adc), GFP_KERNEL);
if (!adc)
return -ENOMEM;
spin_lock_init(&adc->lock);
adc->pdev = pdev;
adc->prescale = S3C2410_ADCCON_PRSCVL(49);
adc->vdd = devm_regulator_get(dev, "vdd");
if (IS_ERR(adc->vdd)) {
dev_err(dev, "operating without regulator \"vdd\" .\n");
return PTR_ERR(adc->vdd);
}
adc->irq = platform_get_irq(pdev, 1);
if (adc->irq <= 0) {
dev_err(dev, "failed to get adc irq\n");
return -ENOENT;
}
ret = devm_request_irq(dev, adc->irq, s3c_adc_irq, 0, dev_name(dev),
adc);
if (ret < 0) {
dev_err(dev, "failed to attach adc irq\n");
return ret;
}
adc->clk = devm_clk_get(dev, "adc");
if (IS_ERR(adc->clk)) {
dev_err(dev, "failed to get adc clock\n");
return PTR_ERR(adc->clk);
}
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
adc->regs = devm_ioremap_resource(dev, regs);
if (IS_ERR(adc->regs))
return PTR_ERR(adc->regs);
ret = regulator_enable(adc->vdd);
if (ret)
return ret;
clk_prepare_enable(adc->clk);
tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
/* Enable 12-bit ADC resolution */
if (cpu == TYPE_ADCV12)
tmp |= S3C2416_ADCCON_RESSEL;
if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
tmp |= S3C64XX_ADCCON_RESSEL;
writel(tmp, adc->regs + S3C2410_ADCCON);
dev_info(dev, "attached adc driver\n");
platform_set_drvdata(pdev, adc);
adc_dev = adc;
return 0;
}
static int s3c_adc_remove(struct platform_device *pdev)
{
struct adc_device *adc = platform_get_drvdata(pdev);
clk_disable_unprepare(adc->clk);
regulator_disable(adc->vdd);
return 0;
}
#ifdef CONFIG_PM
static int s3c_adc_suspend(struct device *dev)
{
struct adc_device *adc = dev_get_drvdata(dev);
unsigned long flags;
u32 con;
spin_lock_irqsave(&adc->lock, flags);
con = readl(adc->regs + S3C2410_ADCCON);
con |= S3C2410_ADCCON_STDBM;
writel(con, adc->regs + S3C2410_ADCCON);
disable_irq(adc->irq);
spin_unlock_irqrestore(&adc->lock, flags);
clk_disable(adc->clk);
regulator_disable(adc->vdd);
return 0;
}
static int s3c_adc_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct adc_device *adc = platform_get_drvdata(pdev);
enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;
int ret;
unsigned long tmp;
ret = regulator_enable(adc->vdd);
if (ret)
return ret;
clk_enable(adc->clk);
enable_irq(adc->irq);
tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;
/* Enable 12-bit ADC resolution */
if (cpu == TYPE_ADCV12)
tmp |= S3C2416_ADCCON_RESSEL;
if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3)
tmp |= S3C64XX_ADCCON_RESSEL;
writel(tmp, adc->regs + S3C2410_ADCCON);
return 0;
}
#else
#define s3c_adc_suspend NULL
#define s3c_adc_resume NULL
#endif
static const struct platform_device_id s3c_adc_driver_ids[] = {
{
.name = "s3c24xx-adc",
.driver_data = TYPE_ADCV1,
}, {
.name = "s3c2443-adc",
.driver_data = TYPE_ADCV11,
}, {
.name = "s3c2416-adc",
.driver_data = TYPE_ADCV12,
}, {
.name = "s3c64xx-adc",
.driver_data = TYPE_ADCV2,
}, {
.name = "samsung-adc-v3",
.driver_data = TYPE_ADCV3,
},
{ }
};
MODULE_DEVICE_TABLE(platform, s3c_adc_driver_ids);
static const struct dev_pm_ops adc_pm_ops = {
.suspend = s3c_adc_suspend,
.resume = s3c_adc_resume,
};
static struct platform_driver s3c_adc_driver = {
.id_table = s3c_adc_driver_ids,
.driver = {
.name = "s3c-adc",
.pm = &adc_pm_ops,
},
.probe = s3c_adc_probe,
.remove = s3c_adc_remove,
};
static int __init adc_init(void)
{
int ret;
ret = platform_driver_register(&s3c_adc_driver);
if (ret)
printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
return ret;
}
module_init(adc_init);