501 lines
11 KiB
C
501 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 = isl12026_probe_new,
|
|
.remove = isl12026_remove,
|
|
};
|
|
|
|
module_i2c_driver(isl12026_driver);
|
|
|
|
MODULE_DESCRIPTION("ISL 12026 RTC driver");
|
|
MODULE_LICENSE("GPL");
|