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linux/drivers/rtc/rtc-pcf85063.c
Bartosz Golaszewski fdcfd85433 rtc: rework rtc_register_device() resource management 
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
2020-11-19 12:50:12 +01:00

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// SPDX-License-Identifier: GPL-2.0
/*
* An I2C driver for the PCF85063 RTC
* Copyright 2014 Rose Technology
*
* Author: Søren Andersen <san@rosetechnology.dk>
* Maintainers: http://www.nslu2-linux.org/
*
* Copyright (C) 2019 Micro Crystal AG
* Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
*/
#include <linux/clk-provider.h>
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/pm_wakeirq.h>
#include <linux/regmap.h>
/*
* Information for this driver was pulled from the following datasheets.
*
* https://www.nxp.com/documents/data_sheet/PCF85063A.pdf
* https://www.nxp.com/documents/data_sheet/PCF85063TP.pdf
*
* PCF85063A -- Rev. 6 — 18 November 2015
* PCF85063TP -- Rev. 4 — 6 May 2015
*
* https://www.microcrystal.com/fileadmin/Media/Products/RTC/App.Manual/RV-8263-C7_App-Manual.pdf
* RV8263 -- Rev. 1.0 — January 2019
*/
#define PCF85063_REG_CTRL1 0x00 /* status */
#define PCF85063_REG_CTRL1_CAP_SEL BIT(0)
#define PCF85063_REG_CTRL1_STOP BIT(5)
#define PCF85063_REG_CTRL2 0x01
#define PCF85063_CTRL2_AF BIT(6)
#define PCF85063_CTRL2_AIE BIT(7)
#define PCF85063_REG_OFFSET 0x02
#define PCF85063_OFFSET_SIGN_BIT 6 /* 2's complement sign bit */
#define PCF85063_OFFSET_MODE BIT(7)
#define PCF85063_OFFSET_STEP0 4340
#define PCF85063_OFFSET_STEP1 4069
#define PCF85063_REG_CLKO_F_MASK 0x07 /* frequency mask */
#define PCF85063_REG_CLKO_F_32768HZ 0x00
#define PCF85063_REG_CLKO_F_OFF 0x07
#define PCF85063_REG_RAM 0x03
#define PCF85063_REG_SC 0x04 /* datetime */
#define PCF85063_REG_SC_OS 0x80
#define PCF85063_REG_ALM_S 0x0b
#define PCF85063_AEN BIT(7)
struct pcf85063_config {
struct regmap_config regmap;
unsigned has_alarms:1;
unsigned force_cap_7000:1;
};
struct pcf85063 {
struct rtc_device *rtc;
struct regmap *regmap;
#ifdef CONFIG_COMMON_CLK
struct clk_hw clkout_hw;
#endif
};
static int pcf85063_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
int rc;
u8 regs[7];
/*
* while reading, the time/date registers are blocked and not updated
* anymore until the access is finished. To not lose a second
* event, the access must be finished within one second. So, read all
* time/date registers in one turn.
*/
rc = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_SC, regs,
sizeof(regs));
if (rc)
return rc;
/* if the clock has lost its power it makes no sense to use its time */
if (regs[0] & PCF85063_REG_SC_OS) {
dev_warn(&pcf85063->rtc->dev, "Power loss detected, invalid time\n");
return -EINVAL;
}
tm->tm_sec = bcd2bin(regs[0] & 0x7F);
tm->tm_min = bcd2bin(regs[1] & 0x7F);
tm->tm_hour = bcd2bin(regs[2] & 0x3F); /* rtc hr 0-23 */
tm->tm_mday = bcd2bin(regs[3] & 0x3F);
tm->tm_wday = regs[4] & 0x07;
tm->tm_mon = bcd2bin(regs[5] & 0x1F) - 1; /* rtc mn 1-12 */
tm->tm_year = bcd2bin(regs[6]);
tm->tm_year += 100;
return 0;
}
static int pcf85063_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
int rc;
u8 regs[7];
/*
* to accurately set the time, reset the divider chain and keep it in
* reset state until all time/date registers are written
*/
rc = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
PCF85063_REG_CTRL1_STOP,
PCF85063_REG_CTRL1_STOP);
if (rc)
return rc;
/* hours, minutes and seconds */
regs[0] = bin2bcd(tm->tm_sec) & 0x7F; /* clear OS flag */
regs[1] = bin2bcd(tm->tm_min);
regs[2] = bin2bcd(tm->tm_hour);
/* Day of month, 1 - 31 */
regs[3] = bin2bcd(tm->tm_mday);
/* Day, 0 - 6 */
regs[4] = tm->tm_wday & 0x07;
/* month, 1 - 12 */
regs[5] = bin2bcd(tm->tm_mon + 1);
/* year and century */
regs[6] = bin2bcd(tm->tm_year - 100);
/* write all registers at once */
rc = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_SC,
regs, sizeof(regs));
if (rc)
return rc;
/*
* Write the control register as a separate action since the size of
* the register space is different between the PCF85063TP and
* PCF85063A devices. The rollover point can not be used.
*/
return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
PCF85063_REG_CTRL1_STOP, 0);
}
static int pcf85063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
u8 buf[4];
unsigned int val;
int ret;
ret = regmap_bulk_read(pcf85063->regmap, PCF85063_REG_ALM_S,
buf, sizeof(buf));
if (ret)
return ret;
alrm->time.tm_sec = bcd2bin(buf[0]);
alrm->time.tm_min = bcd2bin(buf[1]);
alrm->time.tm_hour = bcd2bin(buf[2]);
alrm->time.tm_mday = bcd2bin(buf[3]);
ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val);
if (ret)
return ret;
alrm->enabled = !!(val & PCF85063_CTRL2_AIE);
return 0;
}
static int pcf85063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
u8 buf[5];
int ret;
buf[0] = bin2bcd(alrm->time.tm_sec);
buf[1] = bin2bcd(alrm->time.tm_min);
buf[2] = bin2bcd(alrm->time.tm_hour);
buf[3] = bin2bcd(alrm->time.tm_mday);
buf[4] = PCF85063_AEN; /* Do not match on week day */
ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF, 0);
if (ret)
return ret;
ret = regmap_bulk_write(pcf85063->regmap, PCF85063_REG_ALM_S,
buf, sizeof(buf));
if (ret)
return ret;
return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
alrm->enabled ? PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF : PCF85063_CTRL2_AF);
}
static int pcf85063_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
PCF85063_CTRL2_AIE,
enabled ? PCF85063_CTRL2_AIE : 0);
}
static irqreturn_t pcf85063_rtc_handle_irq(int irq, void *dev_id)
{
struct pcf85063 *pcf85063 = dev_id;
unsigned int val;
int err;
err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &val);
if (err)
return IRQ_NONE;
if (val & PCF85063_CTRL2_AF) {
rtc_update_irq(pcf85063->rtc, 1, RTC_IRQF | RTC_AF);
regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
PCF85063_CTRL2_AIE | PCF85063_CTRL2_AF,
0);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int pcf85063_read_offset(struct device *dev, long *offset)
{
struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
long val;
u32 reg;
int ret;
ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, &reg);
if (ret < 0)
return ret;
val = sign_extend32(reg & ~PCF85063_OFFSET_MODE,
PCF85063_OFFSET_SIGN_BIT);
if (reg & PCF85063_OFFSET_MODE)
*offset = val * PCF85063_OFFSET_STEP1;
else
*offset = val * PCF85063_OFFSET_STEP0;
return 0;
}
static int pcf85063_set_offset(struct device *dev, long offset)
{
struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
s8 mode0, mode1, reg;
unsigned int error0, error1;
if (offset > PCF85063_OFFSET_STEP0 * 63)
return -ERANGE;
if (offset < PCF85063_OFFSET_STEP0 * -64)
return -ERANGE;
mode0 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP0);
mode1 = DIV_ROUND_CLOSEST(offset, PCF85063_OFFSET_STEP1);
error0 = abs(offset - (mode0 * PCF85063_OFFSET_STEP0));
error1 = abs(offset - (mode1 * PCF85063_OFFSET_STEP1));
if (mode1 > 63 || mode1 < -64 || error0 < error1)
reg = mode0 & ~PCF85063_OFFSET_MODE;
else
reg = mode1 | PCF85063_OFFSET_MODE;
return regmap_write(pcf85063->regmap, PCF85063_REG_OFFSET, reg);
}
static int pcf85063_ioctl(struct device *dev, unsigned int cmd,
unsigned long arg)
{
struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
int status, ret = 0;
switch (cmd) {
case RTC_VL_READ:
ret = regmap_read(pcf85063->regmap, PCF85063_REG_SC, &status);
if (ret < 0)
return ret;
status = status & PCF85063_REG_SC_OS ? RTC_VL_DATA_INVALID : 0;
return put_user(status, (unsigned int __user *)arg);
default:
return -ENOIOCTLCMD;
}
}
static const struct rtc_class_ops pcf85063_rtc_ops = {
.read_time = pcf85063_rtc_read_time,
.set_time = pcf85063_rtc_set_time,
.read_offset = pcf85063_read_offset,
.set_offset = pcf85063_set_offset,
.ioctl = pcf85063_ioctl,
};
static const struct rtc_class_ops pcf85063_rtc_ops_alarm = {
.read_time = pcf85063_rtc_read_time,
.set_time = pcf85063_rtc_set_time,
.read_offset = pcf85063_read_offset,
.set_offset = pcf85063_set_offset,
.read_alarm = pcf85063_rtc_read_alarm,
.set_alarm = pcf85063_rtc_set_alarm,
.alarm_irq_enable = pcf85063_rtc_alarm_irq_enable,
.ioctl = pcf85063_ioctl,
};
static int pcf85063_nvmem_read(void *priv, unsigned int offset,
void *val, size_t bytes)
{
return regmap_read(priv, PCF85063_REG_RAM, val);
}
static int pcf85063_nvmem_write(void *priv, unsigned int offset,
void *val, size_t bytes)
{
return regmap_write(priv, PCF85063_REG_RAM, *(u8 *)val);
}
static int pcf85063_load_capacitance(struct pcf85063 *pcf85063,
const struct device_node *np,
unsigned int force_cap)
{
u32 load = 7000;
u8 reg = 0;
if (force_cap)
load = force_cap;
else
of_property_read_u32(np, "quartz-load-femtofarads", &load);
switch (load) {
default:
dev_warn(&pcf85063->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 7000",
load);
fallthrough;
case 7000:
break;
case 12500:
reg = PCF85063_REG_CTRL1_CAP_SEL;
break;
}
return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
PCF85063_REG_CTRL1_CAP_SEL, reg);
}
#ifdef CONFIG_COMMON_CLK
/*
* Handling of the clkout
*/
#define clkout_hw_to_pcf85063(_hw) container_of(_hw, struct pcf85063, clkout_hw)
static int clkout_rates[] = {
32768,
16384,
8192,
4096,
2048,
1024,
1,
0
};
static unsigned long pcf85063_clkout_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
unsigned int buf;
int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
if (ret < 0)
return 0;
buf &= PCF85063_REG_CLKO_F_MASK;
return clkout_rates[buf];
}
static long pcf85063_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
int i;
for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
if (clkout_rates[i] <= rate)
return clkout_rates[i];
return 0;
}
static int pcf85063_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
int i;
for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
if (clkout_rates[i] == rate)
return regmap_update_bits(pcf85063->regmap,
PCF85063_REG_CTRL2,
PCF85063_REG_CLKO_F_MASK, i);
return -EINVAL;
}
static int pcf85063_clkout_control(struct clk_hw *hw, bool enable)
{
struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
unsigned int buf;
int ret;
ret = regmap_read(pcf85063->regmap, PCF85063_REG_OFFSET, &buf);
if (ret < 0)
return ret;
buf &= PCF85063_REG_CLKO_F_MASK;
if (enable) {
if (buf == PCF85063_REG_CLKO_F_OFF)
buf = PCF85063_REG_CLKO_F_32768HZ;
else
return 0;
} else {
if (buf != PCF85063_REG_CLKO_F_OFF)
buf = PCF85063_REG_CLKO_F_OFF;
else
return 0;
}
return regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL2,
PCF85063_REG_CLKO_F_MASK, buf);
}
static int pcf85063_clkout_prepare(struct clk_hw *hw)
{
return pcf85063_clkout_control(hw, 1);
}
static void pcf85063_clkout_unprepare(struct clk_hw *hw)
{
pcf85063_clkout_control(hw, 0);
}
static int pcf85063_clkout_is_prepared(struct clk_hw *hw)
{
struct pcf85063 *pcf85063 = clkout_hw_to_pcf85063(hw);
unsigned int buf;
int ret = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL2, &buf);
if (ret < 0)
return 0;
return (buf & PCF85063_REG_CLKO_F_MASK) != PCF85063_REG_CLKO_F_OFF;
}
static const struct clk_ops pcf85063_clkout_ops = {
.prepare = pcf85063_clkout_prepare,
.unprepare = pcf85063_clkout_unprepare,
.is_prepared = pcf85063_clkout_is_prepared,
.recalc_rate = pcf85063_clkout_recalc_rate,
.round_rate = pcf85063_clkout_round_rate,
.set_rate = pcf85063_clkout_set_rate,
};
static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063)
{
struct clk *clk;
struct clk_init_data init;
init.name = "pcf85063-clkout";
init.ops = &pcf85063_clkout_ops;
init.flags = 0;
init.parent_names = NULL;
init.num_parents = 0;
pcf85063->clkout_hw.init = &init;
/* optional override of the clockname */
of_property_read_string(pcf85063->rtc->dev.of_node,
"clock-output-names", &init.name);
/* register the clock */
clk = devm_clk_register(&pcf85063->rtc->dev, &pcf85063->clkout_hw);
if (!IS_ERR(clk))
of_clk_add_provider(pcf85063->rtc->dev.of_node,
of_clk_src_simple_get, clk);
return clk;
}
#endif
static const struct pcf85063_config pcf85063a_config = {
.regmap = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0x11,
},
.has_alarms = 1,
};
static const struct pcf85063_config pcf85063tp_config = {
.regmap = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0x0a,
},
};
static const struct pcf85063_config rv8263_config = {
.regmap = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0x11,
},
.has_alarms = 1,
.force_cap_7000 = 1,
};
static int pcf85063_probe(struct i2c_client *client)
{
struct pcf85063 *pcf85063;
unsigned int tmp;
int err;
const struct pcf85063_config *config = &pcf85063tp_config;
const void *data = of_device_get_match_data(&client->dev);
struct nvmem_config nvmem_cfg = {
.name = "pcf85063_nvram",
.reg_read = pcf85063_nvmem_read,
.reg_write = pcf85063_nvmem_write,
.type = NVMEM_TYPE_BATTERY_BACKED,
.size = 1,
};
dev_dbg(&client->dev, "%s\n", __func__);
pcf85063 = devm_kzalloc(&client->dev, sizeof(struct pcf85063),
GFP_KERNEL);
if (!pcf85063)
return -ENOMEM;
if (data)
config = data;
pcf85063->regmap = devm_regmap_init_i2c(client, &config->regmap);
if (IS_ERR(pcf85063->regmap))
return PTR_ERR(pcf85063->regmap);
i2c_set_clientdata(client, pcf85063);
err = regmap_read(pcf85063->regmap, PCF85063_REG_CTRL1, &tmp);
if (err) {
dev_err(&client->dev, "RTC chip is not present\n");
return err;
}
pcf85063->rtc = devm_rtc_allocate_device(&client->dev);
if (IS_ERR(pcf85063->rtc))
return PTR_ERR(pcf85063->rtc);
err = pcf85063_load_capacitance(pcf85063, client->dev.of_node,
config->force_cap_7000 ? 7000 : 0);
if (err < 0)
dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
err);
pcf85063->rtc->ops = &pcf85063_rtc_ops;
pcf85063->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
pcf85063->rtc->range_max = RTC_TIMESTAMP_END_2099;
pcf85063->rtc->uie_unsupported = 1;
if (config->has_alarms && client->irq > 0) {
err = devm_request_threaded_irq(&client->dev, client->irq,
NULL, pcf85063_rtc_handle_irq,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
"pcf85063", pcf85063);
if (err) {
dev_warn(&pcf85063->rtc->dev,
"unable to request IRQ, alarms disabled\n");
} else {
pcf85063->rtc->ops = &pcf85063_rtc_ops_alarm;
device_init_wakeup(&client->dev, true);
err = dev_pm_set_wake_irq(&client->dev, client->irq);
if (err)
dev_err(&pcf85063->rtc->dev,
"failed to enable irq wake\n");
}
}
nvmem_cfg.priv = pcf85063->regmap;
devm_rtc_nvmem_register(pcf85063->rtc, &nvmem_cfg);
#ifdef CONFIG_COMMON_CLK
/* register clk in common clk framework */
pcf85063_clkout_register_clk(pcf85063);
#endif
return devm_rtc_register_device(pcf85063->rtc);
}
#ifdef CONFIG_OF
static const struct of_device_id pcf85063_of_match[] = {
{ .compatible = "nxp,pcf85063", .data = &pcf85063tp_config },
{ .compatible = "nxp,pcf85063tp", .data = &pcf85063tp_config },
{ .compatible = "nxp,pcf85063a", .data = &pcf85063a_config },
{ .compatible = "microcrystal,rv8263", .data = &rv8263_config },
{}
};
MODULE_DEVICE_TABLE(of, pcf85063_of_match);
#endif
static struct i2c_driver pcf85063_driver = {
.driver = {
.name = "rtc-pcf85063",
.of_match_table = of_match_ptr(pcf85063_of_match),
},
.probe_new = pcf85063_probe,
};
module_i2c_driver(pcf85063_driver);
MODULE_AUTHOR("Søren Andersen <san@rosetechnology.dk>");
MODULE_DESCRIPTION("PCF85063 RTC driver");
MODULE_LICENSE("GPL");
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