linux-stable/drivers/rtc/rtc-isl12026.c
Uwe Kleine-König ed5c2f5fd1 i2c: Make remove callback return void
The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-16 12:46:26 +02:00

500 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* An I2C driver for the Intersil ISL 12026
*
* Copyright (c) 2018 Cavium, Inc.
*/
#include <linux/bcd.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/rtc.h>
#include <linux/slab.h>
/* register offsets */
#define ISL12026_REG_PWR 0x14
# define ISL12026_REG_PWR_BSW BIT(6)
# define ISL12026_REG_PWR_SBIB BIT(7)
#define ISL12026_REG_SC 0x30
#define ISL12026_REG_HR 0x32
# define ISL12026_REG_HR_MIL BIT(7) /* military or 24 hour time */
#define ISL12026_REG_SR 0x3f
# define ISL12026_REG_SR_RTCF BIT(0)
# define ISL12026_REG_SR_WEL BIT(1)
# define ISL12026_REG_SR_RWEL BIT(2)
# define ISL12026_REG_SR_MBZ BIT(3)
# define ISL12026_REG_SR_OSCF BIT(4)
/* The EEPROM array responds at i2c address 0x57 */
#define ISL12026_EEPROM_ADDR 0x57
#define ISL12026_PAGESIZE 16
#define ISL12026_NVMEM_WRITE_TIME 20
struct isl12026 {
struct rtc_device *rtc;
struct i2c_client *nvm_client;
};
static int isl12026_read_reg(struct i2c_client *client, int reg)
{
u8 addr[] = {0, reg};
u8 val;
int ret;
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = 0,
.len = sizeof(addr),
.buf = addr
}, {
.addr = client->addr,
.flags = I2C_M_RD,
.len = 1,
.buf = &val
}
};
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (ret != ARRAY_SIZE(msgs)) {
dev_err(&client->dev, "read reg error, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
} else {
ret = val;
}
return ret;
}
static int isl12026_arm_write(struct i2c_client *client)
{
int ret;
u8 op[3];
struct i2c_msg msg = {
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = op
};
/* Set SR.WEL */
op[0] = 0;
op[1] = ISL12026_REG_SR;
op[2] = ISL12026_REG_SR_WEL;
msg.len = 3;
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret != 1) {
dev_err(&client->dev, "write error SR.WEL, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
goto out;
}
/* Set SR.WEL and SR.RWEL */
op[2] = ISL12026_REG_SR_WEL | ISL12026_REG_SR_RWEL;
msg.len = 3;
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret != 1) {
dev_err(&client->dev,
"write error SR.WEL|SR.RWEL, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
goto out;
} else {
ret = 0;
}
out:
return ret;
}
static int isl12026_disarm_write(struct i2c_client *client)
{
int ret;
u8 op[3] = {0, ISL12026_REG_SR, 0};
struct i2c_msg msg = {
.addr = client->addr,
.flags = 0,
.len = sizeof(op),
.buf = op
};
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret != 1) {
dev_err(&client->dev,
"write error SR, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
} else {
ret = 0;
}
return ret;
}
static int isl12026_write_reg(struct i2c_client *client, int reg, u8 val)
{
int ret;
u8 op[3] = {0, reg, val};
struct i2c_msg msg = {
.addr = client->addr,
.flags = 0,
.len = sizeof(op),
.buf = op
};
ret = isl12026_arm_write(client);
if (ret)
return ret;
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret != 1) {
dev_err(&client->dev, "write error CCR, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
goto out;
}
msleep(ISL12026_NVMEM_WRITE_TIME);
ret = isl12026_disarm_write(client);
out:
return ret;
}
static int isl12026_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
int ret;
u8 op[10];
struct i2c_msg msg = {
.addr = client->addr,
.flags = 0,
.len = sizeof(op),
.buf = op
};
ret = isl12026_arm_write(client);
if (ret)
return ret;
/* Set the CCR registers */
op[0] = 0;
op[1] = ISL12026_REG_SC;
op[2] = bin2bcd(tm->tm_sec); /* SC */
op[3] = bin2bcd(tm->tm_min); /* MN */
op[4] = bin2bcd(tm->tm_hour) | ISL12026_REG_HR_MIL; /* HR */
op[5] = bin2bcd(tm->tm_mday); /* DT */
op[6] = bin2bcd(tm->tm_mon + 1); /* MO */
op[7] = bin2bcd(tm->tm_year % 100); /* YR */
op[8] = bin2bcd(tm->tm_wday & 7); /* DW */
op[9] = bin2bcd(tm->tm_year >= 100 ? 20 : 19); /* Y2K */
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret != 1) {
dev_err(&client->dev, "write error CCR, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
goto out;
}
ret = isl12026_disarm_write(client);
out:
return ret;
}
static int isl12026_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
u8 ccr[8];
u8 addr[2];
u8 sr;
int ret;
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = 0,
.len = sizeof(addr),
.buf = addr
}, {
.addr = client->addr,
.flags = I2C_M_RD,
}
};
/* First, read SR */
addr[0] = 0;
addr[1] = ISL12026_REG_SR;
msgs[1].len = 1;
msgs[1].buf = &sr;
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (ret != ARRAY_SIZE(msgs)) {
dev_err(&client->dev, "read error, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
goto out;
}
if (sr & ISL12026_REG_SR_RTCF)
dev_warn(&client->dev, "Real-Time Clock Failure on read\n");
if (sr & ISL12026_REG_SR_OSCF)
dev_warn(&client->dev, "Oscillator Failure on read\n");
/* Second, CCR regs */
addr[0] = 0;
addr[1] = ISL12026_REG_SC;
msgs[1].len = sizeof(ccr);
msgs[1].buf = ccr;
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (ret != ARRAY_SIZE(msgs)) {
dev_err(&client->dev, "read error, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
goto out;
}
tm->tm_sec = bcd2bin(ccr[0] & 0x7F);
tm->tm_min = bcd2bin(ccr[1] & 0x7F);
if (ccr[2] & ISL12026_REG_HR_MIL)
tm->tm_hour = bcd2bin(ccr[2] & 0x3F);
else
tm->tm_hour = bcd2bin(ccr[2] & 0x1F) +
((ccr[2] & 0x20) ? 12 : 0);
tm->tm_mday = bcd2bin(ccr[3] & 0x3F);
tm->tm_mon = bcd2bin(ccr[4] & 0x1F) - 1;
tm->tm_year = bcd2bin(ccr[5]);
if (bcd2bin(ccr[7]) == 20)
tm->tm_year += 100;
tm->tm_wday = ccr[6] & 0x07;
ret = 0;
out:
return ret;
}
static const struct rtc_class_ops isl12026_rtc_ops = {
.read_time = isl12026_rtc_read_time,
.set_time = isl12026_rtc_set_time,
};
static int isl12026_nvm_read(void *p, unsigned int offset,
void *val, size_t bytes)
{
struct isl12026 *priv = p;
int ret;
u8 addr[2];
struct i2c_msg msgs[] = {
{
.addr = priv->nvm_client->addr,
.flags = 0,
.len = sizeof(addr),
.buf = addr
}, {
.addr = priv->nvm_client->addr,
.flags = I2C_M_RD,
.buf = val
}
};
/*
* offset and bytes checked and limited by nvmem core, so
* proceed without further checks.
*/
ret = mutex_lock_interruptible(&priv->rtc->ops_lock);
if (ret)
return ret;
/* 2 bytes of address, most significant first */
addr[0] = offset >> 8;
addr[1] = offset;
msgs[1].len = bytes;
ret = i2c_transfer(priv->nvm_client->adapter, msgs, ARRAY_SIZE(msgs));
mutex_unlock(&priv->rtc->ops_lock);
if (ret != ARRAY_SIZE(msgs)) {
dev_err(&priv->nvm_client->dev,
"nvmem read error, ret=%d\n", ret);
return ret < 0 ? ret : -EIO;
}
return 0;
}
static int isl12026_nvm_write(void *p, unsigned int offset,
void *val, size_t bytes)
{
struct isl12026 *priv = p;
int ret;
u8 *v = val;
size_t chunk_size, num_written;
u8 payload[ISL12026_PAGESIZE + 2]; /* page + 2 address bytes */
struct i2c_msg msgs[] = {
{
.addr = priv->nvm_client->addr,
.flags = 0,
.buf = payload
}
};
/*
* offset and bytes checked and limited by nvmem core, so
* proceed without further checks.
*/
ret = mutex_lock_interruptible(&priv->rtc->ops_lock);
if (ret)
return ret;
num_written = 0;
while (bytes) {
chunk_size = round_down(offset, ISL12026_PAGESIZE) +
ISL12026_PAGESIZE - offset;
chunk_size = min(bytes, chunk_size);
/*
* 2 bytes of address, most significant first, followed
* by page data bytes
*/
memcpy(payload + 2, v + num_written, chunk_size);
payload[0] = offset >> 8;
payload[1] = offset;
msgs[0].len = chunk_size + 2;
ret = i2c_transfer(priv->nvm_client->adapter,
msgs, ARRAY_SIZE(msgs));
if (ret != ARRAY_SIZE(msgs)) {
dev_err(&priv->nvm_client->dev,
"nvmem write error, ret=%d\n", ret);
ret = ret < 0 ? ret : -EIO;
break;
}
ret = 0;
bytes -= chunk_size;
offset += chunk_size;
num_written += chunk_size;
msleep(ISL12026_NVMEM_WRITE_TIME);
}
mutex_unlock(&priv->rtc->ops_lock);
return ret;
}
static void isl12026_force_power_modes(struct i2c_client *client)
{
int ret;
int pwr, requested_pwr;
u32 bsw_val, sbib_val;
bool set_bsw, set_sbib;
/*
* If we can read the of_property, set the specified value.
* If there is an error reading the of_property (likely
* because it does not exist), keep the current value.
*/
ret = of_property_read_u32(client->dev.of_node,
"isil,pwr-bsw", &bsw_val);
set_bsw = (ret == 0);
ret = of_property_read_u32(client->dev.of_node,
"isil,pwr-sbib", &sbib_val);
set_sbib = (ret == 0);
/* Check if PWR.BSW and/or PWR.SBIB need specified values */
if (!set_bsw && !set_sbib)
return;
pwr = isl12026_read_reg(client, ISL12026_REG_PWR);
if (pwr < 0) {
dev_warn(&client->dev, "Error: Failed to read PWR %d\n", pwr);
return;
}
requested_pwr = pwr;
if (set_bsw) {
if (bsw_val)
requested_pwr |= ISL12026_REG_PWR_BSW;
else
requested_pwr &= ~ISL12026_REG_PWR_BSW;
} /* else keep current BSW */
if (set_sbib) {
if (sbib_val)
requested_pwr |= ISL12026_REG_PWR_SBIB;
else
requested_pwr &= ~ISL12026_REG_PWR_SBIB;
} /* else keep current SBIB */
if (pwr >= 0 && pwr != requested_pwr) {
dev_dbg(&client->dev, "PWR: %02x\n", pwr);
dev_dbg(&client->dev, "Updating PWR to: %02x\n", requested_pwr);
isl12026_write_reg(client, ISL12026_REG_PWR, requested_pwr);
}
}
static int isl12026_probe_new(struct i2c_client *client)
{
struct isl12026 *priv;
int ret;
struct nvmem_config nvm_cfg = {
.name = "isl12026-",
.base_dev = &client->dev,
.stride = 1,
.word_size = 1,
.size = 512,
.reg_read = isl12026_nvm_read,
.reg_write = isl12026_nvm_write,
};
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
i2c_set_clientdata(client, priv);
isl12026_force_power_modes(client);
priv->nvm_client = i2c_new_dummy_device(client->adapter, ISL12026_EEPROM_ADDR);
if (IS_ERR(priv->nvm_client))
return PTR_ERR(priv->nvm_client);
priv->rtc = devm_rtc_allocate_device(&client->dev);
ret = PTR_ERR_OR_ZERO(priv->rtc);
if (ret)
return ret;
priv->rtc->ops = &isl12026_rtc_ops;
nvm_cfg.priv = priv;
ret = devm_rtc_nvmem_register(priv->rtc, &nvm_cfg);
if (ret)
return ret;
return devm_rtc_register_device(priv->rtc);
}
static void isl12026_remove(struct i2c_client *client)
{
struct isl12026 *priv = i2c_get_clientdata(client);
i2c_unregister_device(priv->nvm_client);
}
static const struct of_device_id isl12026_dt_match[] = {
{ .compatible = "isil,isl12026" },
{ }
};
MODULE_DEVICE_TABLE(of, isl12026_dt_match);
static struct i2c_driver isl12026_driver = {
.driver = {
.name = "rtc-isl12026",
.of_match_table = isl12026_dt_match,
},
.probe_new = isl12026_probe_new,
.remove = isl12026_remove,
};
module_i2c_driver(isl12026_driver);
MODULE_DESCRIPTION("ISL 12026 RTC driver");
MODULE_LICENSE("GPL");