mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 13:41:51 +00:00
fdcfd85433
rtc_register_device() is a managed interface but it doesn't use devres by itself - instead it marks an rtc_device as "registered" and the devres callback for devm_rtc_allocate_device() takes care of resource release. This doesn't correspond with the design behind devres where managed structures should not be aware of being managed. The correct solution here is to register a separate devres callback for unregistering the device. While at it: rename rtc_register_device() to devm_rtc_register_device() and add it to the list of managed interfaces in devres.rst. This way we can avoid any potential confusion of driver developers who may expect there to exist a corresponding unregister function. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl
257 lines
5.8 KiB
C
257 lines
5.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
// Copyright (C) 2012 Sven Schnelle <svens@stackframe.org>
|
|
|
|
#include <linux/platform_device.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/types.h>
|
|
#include <linux/bcd.h>
|
|
#include <linux/platform_data/rtc-ds2404.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/gpio.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/io.h>
|
|
|
|
#define DS2404_STATUS_REG 0x200
|
|
#define DS2404_CONTROL_REG 0x201
|
|
#define DS2404_RTC_REG 0x202
|
|
|
|
#define DS2404_WRITE_SCRATCHPAD_CMD 0x0f
|
|
#define DS2404_READ_SCRATCHPAD_CMD 0xaa
|
|
#define DS2404_COPY_SCRATCHPAD_CMD 0x55
|
|
#define DS2404_READ_MEMORY_CMD 0xf0
|
|
|
|
#define DS2404_RST 0
|
|
#define DS2404_CLK 1
|
|
#define DS2404_DQ 2
|
|
|
|
struct ds2404_gpio {
|
|
const char *name;
|
|
unsigned int gpio;
|
|
};
|
|
|
|
struct ds2404 {
|
|
struct ds2404_gpio *gpio;
|
|
struct rtc_device *rtc;
|
|
};
|
|
|
|
static struct ds2404_gpio ds2404_gpio[] = {
|
|
{ "RTC RST", 0 },
|
|
{ "RTC CLK", 0 },
|
|
{ "RTC DQ", 0 },
|
|
};
|
|
|
|
static int ds2404_gpio_map(struct ds2404 *chip, struct platform_device *pdev,
|
|
struct ds2404_platform_data *pdata)
|
|
{
|
|
int i, err;
|
|
|
|
ds2404_gpio[DS2404_RST].gpio = pdata->gpio_rst;
|
|
ds2404_gpio[DS2404_CLK].gpio = pdata->gpio_clk;
|
|
ds2404_gpio[DS2404_DQ].gpio = pdata->gpio_dq;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(ds2404_gpio); i++) {
|
|
err = gpio_request(ds2404_gpio[i].gpio, ds2404_gpio[i].name);
|
|
if (err) {
|
|
dev_err(&pdev->dev, "error mapping gpio %s: %d\n",
|
|
ds2404_gpio[i].name, err);
|
|
goto err_request;
|
|
}
|
|
if (i != DS2404_DQ)
|
|
gpio_direction_output(ds2404_gpio[i].gpio, 1);
|
|
}
|
|
|
|
chip->gpio = ds2404_gpio;
|
|
return 0;
|
|
|
|
err_request:
|
|
while (--i >= 0)
|
|
gpio_free(ds2404_gpio[i].gpio);
|
|
return err;
|
|
}
|
|
|
|
static void ds2404_gpio_unmap(void *data)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(ds2404_gpio); i++)
|
|
gpio_free(ds2404_gpio[i].gpio);
|
|
}
|
|
|
|
static void ds2404_reset(struct device *dev)
|
|
{
|
|
gpio_set_value(ds2404_gpio[DS2404_RST].gpio, 0);
|
|
udelay(1000);
|
|
gpio_set_value(ds2404_gpio[DS2404_RST].gpio, 1);
|
|
gpio_set_value(ds2404_gpio[DS2404_CLK].gpio, 0);
|
|
gpio_direction_output(ds2404_gpio[DS2404_DQ].gpio, 0);
|
|
udelay(10);
|
|
}
|
|
|
|
static void ds2404_write_byte(struct device *dev, u8 byte)
|
|
{
|
|
int i;
|
|
|
|
gpio_direction_output(ds2404_gpio[DS2404_DQ].gpio, 1);
|
|
for (i = 0; i < 8; i++) {
|
|
gpio_set_value(ds2404_gpio[DS2404_DQ].gpio, byte & (1 << i));
|
|
udelay(10);
|
|
gpio_set_value(ds2404_gpio[DS2404_CLK].gpio, 1);
|
|
udelay(10);
|
|
gpio_set_value(ds2404_gpio[DS2404_CLK].gpio, 0);
|
|
udelay(10);
|
|
}
|
|
}
|
|
|
|
static u8 ds2404_read_byte(struct device *dev)
|
|
{
|
|
int i;
|
|
u8 ret = 0;
|
|
|
|
gpio_direction_input(ds2404_gpio[DS2404_DQ].gpio);
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
gpio_set_value(ds2404_gpio[DS2404_CLK].gpio, 0);
|
|
udelay(10);
|
|
if (gpio_get_value(ds2404_gpio[DS2404_DQ].gpio))
|
|
ret |= 1 << i;
|
|
gpio_set_value(ds2404_gpio[DS2404_CLK].gpio, 1);
|
|
udelay(10);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void ds2404_read_memory(struct device *dev, u16 offset,
|
|
int length, u8 *out)
|
|
{
|
|
ds2404_reset(dev);
|
|
ds2404_write_byte(dev, DS2404_READ_MEMORY_CMD);
|
|
ds2404_write_byte(dev, offset & 0xff);
|
|
ds2404_write_byte(dev, (offset >> 8) & 0xff);
|
|
while (length--)
|
|
*out++ = ds2404_read_byte(dev);
|
|
}
|
|
|
|
static void ds2404_write_memory(struct device *dev, u16 offset,
|
|
int length, u8 *out)
|
|
{
|
|
int i;
|
|
u8 ta01, ta02, es;
|
|
|
|
ds2404_reset(dev);
|
|
ds2404_write_byte(dev, DS2404_WRITE_SCRATCHPAD_CMD);
|
|
ds2404_write_byte(dev, offset & 0xff);
|
|
ds2404_write_byte(dev, (offset >> 8) & 0xff);
|
|
|
|
for (i = 0; i < length; i++)
|
|
ds2404_write_byte(dev, out[i]);
|
|
|
|
ds2404_reset(dev);
|
|
ds2404_write_byte(dev, DS2404_READ_SCRATCHPAD_CMD);
|
|
|
|
ta01 = ds2404_read_byte(dev);
|
|
ta02 = ds2404_read_byte(dev);
|
|
es = ds2404_read_byte(dev);
|
|
|
|
for (i = 0; i < length; i++) {
|
|
if (out[i] != ds2404_read_byte(dev)) {
|
|
dev_err(dev, "read invalid data\n");
|
|
return;
|
|
}
|
|
}
|
|
|
|
ds2404_reset(dev);
|
|
ds2404_write_byte(dev, DS2404_COPY_SCRATCHPAD_CMD);
|
|
ds2404_write_byte(dev, ta01);
|
|
ds2404_write_byte(dev, ta02);
|
|
ds2404_write_byte(dev, es);
|
|
|
|
gpio_direction_input(ds2404_gpio[DS2404_DQ].gpio);
|
|
while (gpio_get_value(ds2404_gpio[DS2404_DQ].gpio))
|
|
;
|
|
}
|
|
|
|
static void ds2404_enable_osc(struct device *dev)
|
|
{
|
|
u8 in[1] = { 0x10 }; /* enable oscillator */
|
|
ds2404_write_memory(dev, 0x201, 1, in);
|
|
}
|
|
|
|
static int ds2404_read_time(struct device *dev, struct rtc_time *dt)
|
|
{
|
|
unsigned long time = 0;
|
|
__le32 hw_time = 0;
|
|
|
|
ds2404_read_memory(dev, 0x203, 4, (u8 *)&hw_time);
|
|
time = le32_to_cpu(hw_time);
|
|
|
|
rtc_time64_to_tm(time, dt);
|
|
return 0;
|
|
}
|
|
|
|
static int ds2404_set_time(struct device *dev, struct rtc_time *dt)
|
|
{
|
|
u32 time = cpu_to_le32(rtc_tm_to_time64(dt));
|
|
ds2404_write_memory(dev, 0x203, 4, (u8 *)&time);
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops ds2404_rtc_ops = {
|
|
.read_time = ds2404_read_time,
|
|
.set_time = ds2404_set_time,
|
|
};
|
|
|
|
static int rtc_probe(struct platform_device *pdev)
|
|
{
|
|
struct ds2404_platform_data *pdata = dev_get_platdata(&pdev->dev);
|
|
struct ds2404 *chip;
|
|
int retval = -EBUSY;
|
|
|
|
chip = devm_kzalloc(&pdev->dev, sizeof(struct ds2404), GFP_KERNEL);
|
|
if (!chip)
|
|
return -ENOMEM;
|
|
|
|
chip->rtc = devm_rtc_allocate_device(&pdev->dev);
|
|
if (IS_ERR(chip->rtc))
|
|
return PTR_ERR(chip->rtc);
|
|
|
|
retval = ds2404_gpio_map(chip, pdev, pdata);
|
|
if (retval)
|
|
return retval;
|
|
|
|
retval = devm_add_action_or_reset(&pdev->dev, ds2404_gpio_unmap, chip);
|
|
if (retval)
|
|
return retval;
|
|
|
|
dev_info(&pdev->dev, "using GPIOs RST:%d, CLK:%d, DQ:%d\n",
|
|
chip->gpio[DS2404_RST].gpio, chip->gpio[DS2404_CLK].gpio,
|
|
chip->gpio[DS2404_DQ].gpio);
|
|
|
|
platform_set_drvdata(pdev, chip);
|
|
|
|
chip->rtc->ops = &ds2404_rtc_ops;
|
|
chip->rtc->range_max = U32_MAX;
|
|
|
|
retval = devm_rtc_register_device(chip->rtc);
|
|
if (retval)
|
|
return retval;
|
|
|
|
ds2404_enable_osc(&pdev->dev);
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver rtc_device_driver = {
|
|
.probe = rtc_probe,
|
|
.driver = {
|
|
.name = "ds2404",
|
|
},
|
|
};
|
|
module_platform_driver(rtc_device_driver);
|
|
|
|
MODULE_DESCRIPTION("DS2404 RTC");
|
|
MODULE_AUTHOR("Sven Schnelle");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:ds2404");
|