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u-boot/drivers/rtc/rv3029.c
Philipp Tomsich a73610d2c6 rtc: rv3029: update to support DM and sync with Linux 4.17 
The "Flamingo" carrier-board for the RK3399-Q7 has a RV3029 populated
and the application will use the off-module RV3029 RTC including the
battery backed SRAM.

To support this use case, this commit includes the following changes:
 * updates the rv3029 driver to use DM
 * implements the read8/write8 operations

This syncs the implementation with the Linux code (based on 4.17),
porting the trickle-charger support from there (with improvements to
avoid unnecessary EEPROM updates) and adheres to the Linux DTS
binding.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Klaus Goger <klaus.goger@theobroma-systems.com>
2018-11-30 21:56:45 +01:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH
*
* Based on a the Linux rtc-rv3029c2.c driver written by:
* Gregory Hermant <gregory.hermant@calao-systems.com>
* Michael Buesch <m@bues.ch>
*/
#include <common.h>
#include <command.h>
#include <dm.h>
#include <i2c.h>
#include <rtc.h>
#define RTC_RV3029_PAGE_LEN 7
/* control section */
#define RV3029_ONOFF_CTRL 0x00
#define RV3029_ONOFF_CTRL_WE BIT(0)
#define RV3029_ONOFF_CTRL_TE BIT(1)
#define RV3029_ONOFF_CTRL_TAR BIT(2)
#define RV3029_ONOFF_CTRL_EERE BIT(3)
#define RV3029_ONOFF_CTRL_SRON BIT(4)
#define RV3029_ONOFF_CTRL_TD0 BIT(5)
#define RV3029_ONOFF_CTRL_TD1 BIT(6)
#define RV3029_ONOFF_CTRL_CLKINT BIT(7)
#define RV3029_IRQ_CTRL 0x01
#define RV3029_IRQ_CTRL_AIE BIT(0)
#define RV3029_IRQ_CTRL_TIE BIT(1)
#define RV3029_IRQ_CTRL_V1IE BIT(2)
#define RV3029_IRQ_CTRL_V2IE BIT(3)
#define RV3029_IRQ_CTRL_SRIE BIT(4)
#define RV3029_IRQ_FLAGS 0x02
#define RV3029_IRQ_FLAGS_AF BIT(0)
#define RV3029_IRQ_FLAGS_TF BIT(1)
#define RV3029_IRQ_FLAGS_V1IF BIT(2)
#define RV3029_IRQ_FLAGS_V2IF BIT(3)
#define RV3029_IRQ_FLAGS_SRF BIT(4)
#define RV3029_STATUS 0x03
#define RV3029_STATUS_VLOW1 BIT(2)
#define RV3029_STATUS_VLOW2 BIT(3)
#define RV3029_STATUS_SR BIT(4)
#define RV3029_STATUS_PON BIT(5)
#define RV3029_STATUS_EEBUSY BIT(7)
#define RV3029_RST_CTRL 0x04
#define RV3029_RST_CTRL_SYSR BIT(4)
#define RV3029_CONTROL_SECTION_LEN 0x05
/* watch section */
#define RV3029_W_SEC 0x08
#define RV3029_W_MINUTES 0x09
#define RV3029_W_HOURS 0x0A
#define RV3029_REG_HR_12_24 BIT(6) /* 24h/12h mode */
#define RV3029_REG_HR_PM BIT(5) /* PM/AM bit in 12h mode */
#define RV3029_W_DATE 0x0B
#define RV3029_W_DAYS 0x0C
#define RV3029_W_MONTHS 0x0D
#define RV3029_W_YEARS 0x0E
/* eeprom control section */
#define RV3029_CONTROL_E2P_EECTRL 0x30
#define RV3029_TRICKLE_1K BIT(4) /* 1.5K resistance */
#define RV3029_TRICKLE_5K BIT(5) /* 5K resistance */
#define RV3029_TRICKLE_20K BIT(6) /* 20K resistance */
#define RV3029_TRICKLE_80K BIT(7) /* 80K resistance */
#define RV3029_TRICKLE_MASK (RV3029_TRICKLE_1K |\
RV3029_TRICKLE_5K |\
RV3029_TRICKLE_20K |\
RV3029_TRICKLE_80K)
#define RV3029_TRICKLE_SHIFT 4
static int rv3029_rtc_get(struct udevice *dev, struct rtc_time *tm)
{
u8 regs[RTC_RV3029_PAGE_LEN];
int ret;
ret = dm_i2c_read(dev, RV3029_W_SEC, regs, sizeof(regs));
if (ret < 0) {
printf("%s: error reading RTC: %x\n", __func__, ret);
return -EIO;
}
tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
/* HR field has a more complex interpretation */
{
const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
if (_hr & RV3029_REG_HR_12_24) {
/* 12h format */
tm->tm_hour = bcd2bin(_hr & 0x1f);
if (_hr & RV3029_REG_HR_PM) /* PM flag set */
tm->tm_hour += 12;
} else {
/* 24h format */
tm->tm_hour = bcd2bin(_hr & 0x3f);
}
}
tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
/* RTC supports only years > 1999 */
tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 2000;
tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
tm->tm_yday = 0;
tm->tm_isdst = 0;
debug("%s: %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n",
__func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
return 0;
}
static int rv3029_rtc_set(struct udevice *dev, const struct rtc_time *tm)
{
u8 regs[RTC_RV3029_PAGE_LEN];
debug("%s: %4d-%02d-%02d (wday=%d( %2d:%02d:%02d\n",
__func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
if (tm->tm_year < 2000) {
printf("%s: year %d (before 2000) not supported\n",
__func__, tm->tm_year);
return -EINVAL;
}
regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 2000);
return dm_i2c_write(dev, RV3029_W_SEC, regs, sizeof(regs));
}
static int rv3029_rtc_reset(struct udevice *dev)
{
u8 ctrl = RV3029_RST_CTRL_SYSR;
unsigned long start;
const unsigned long timeout_ms = 10000;
int ret;
/* trigger the system-reset */
ret = dm_i2c_write(dev, RV3029_RST_CTRL, &ctrl, 1);
if (ret < 0)
return -EIO;
/* wait for the system-reset to complete */
start = get_timer(0);
do {
if (get_timer(start) > timeout_ms)
return -ETIMEDOUT;
ret = dm_i2c_read(dev, RV3029_RST_CTRL, &ctrl, 1);
if (ret < 0)
return -EIO;
} while (ctrl & RV3029_RST_CTRL_SYSR);
return 0;
}
static int rv3029_rtc_read8(struct udevice *dev, unsigned int reg)
{
u8 data;
int ret;
ret = dm_i2c_read(dev, reg, &data, sizeof(data));
return ret < 0 ? ret : data;
}
static int rv3029_rtc_write8(struct udevice *dev, unsigned int reg, int val)
{
u8 data = val;
return dm_i2c_write(dev, reg, &data, 1);
}
#if defined(OF_CONTROL)
static int rv3029_get_sr(struct udevice *dev, u8 *buf)
{
int ret = dm_i2c_read(dev, RV3029_STATUS, buf, 1);
if (ret < 0)
return -EIO;
dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
return 0;
}
static int rv3029_set_sr(struct udevice *dev, u8 val)
{
int ret;
ret = dm_i2c_read(dev, RV3029_STATUS, &val, 1);
if (ret < 0)
return -EIO;
dev_dbg(dev, "status = 0x%.2x (%d)\n", val, val);
return 0;
}
static int rv3029_eeprom_busywait(struct udevice *dev)
{
int i, ret;
u8 sr;
for (i = 100; i > 0; i--) {
ret = rv3029_get_sr(dev, &sr);
if (ret < 0)
break;
if (!(sr & RV3029_STATUS_EEBUSY))
break;
udelay(10000);
}
if (i <= 0) {
dev_err(dev, "EEPROM busy wait timeout.\n");
return -ETIMEDOUT;
}
return ret;
}
static int rv3029_update_bits(struct udevice *dev, u8 reg, u8 mask, u8 set)
{
u8 buf;
int ret;
ret = dm_i2c_read(dev, reg, &buf, 1);
if (ret < 0)
return ret;
if ((buf & mask) == (set && mask))
return 0;
buf = (buf & ~mask) | (set & mask);
ret = dm_i2c_read(dev, reg, &buf, 1);
if (ret < 0)
return ret;
return 0;
}
static int rv3029_eeprom_exit(struct udevice *dev)
{
/* Re-enable eeprom refresh */
return rv3029_update_bits(dev, RV3029_ONOFF_CTRL,
RV3029_ONOFF_CTRL_EERE,
RV3029_ONOFF_CTRL_EERE);
}
static int rv3029_eeprom_enter(struct udevice *dev)
{
int ret;
u8 sr;
/* Check whether we are in the allowed voltage range. */
ret = rv3029_get_sr(dev, &sr);
if (ret < 0)
return ret;
if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
/* We clear the bits and retry once just in case
* we had a brown out in early startup.
*/
sr &= ~RV3029_STATUS_VLOW1;
sr &= ~RV3029_STATUS_VLOW2;
ret = rv3029_set_sr(dev, sr);
if (ret < 0)
return ret;
udelay(10000);
ret = rv3029_get_sr(dev, &sr);
if (ret < 0)
return ret;
if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
dev_err(dev, "Supply voltage is too low to safely access the EEPROM.\n");
return -ENODEV;
}
}
/* Disable eeprom refresh. */
ret = rv3029_update_bits(dev,
RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE, 0);
if (ret < 0)
return ret;
/* Wait for any previous eeprom accesses to finish. */
ret = rv3029_eeprom_busywait(dev);
if (ret < 0)
rv3029_eeprom_exit(dev);
return ret;
}
static int rv3029_eeprom_read(struct udevice *dev, u8 reg,
u8 buf[], size_t len)
{
int ret, err;
err = rv3029_eeprom_enter(dev);
if (err < 0)
return err;
ret = dm_i2c_read(dev, reg, buf, len);
err = rv3029_eeprom_exit(dev);
if (err < 0)
return err;
return ret;
}
static int rv3029_eeprom_write(struct udevice *dev, u8 reg,
u8 const buf[], size_t len)
{
int ret;
size_t i;
u8 tmp;
ret = rv3029_eeprom_enter(dev);
if (ret < 0)
return ret;
for (i = 0; i < len; i++, reg++) {
ret = dm_i2c_read(dev, reg, &tmp, 1);
if (ret < 0)
break;
if (tmp != buf[i]) {
ret = dm_i2c_write(dev, reg, &buf[i], 1);
if (ret < 0)
break;
}
ret = rv3029_eeprom_busywait(dev);
if (ret < 0)
break;
}
ret = rv3029_eeprom_exit(dev);
if (ret < 0)
return ret;
return 0;
}
static int rv3029_eeprom_update_bits(struct udevice *dev,
u8 reg, u8 mask, u8 set)
{
u8 buf;
int ret;
ret = rv3029_eeprom_read(dev, reg, &buf, 1);
if (ret < 0)
return ret;
/*
* If the EEPROM already reads the correct bitpattern, we don't need
* to update it.
*/
if ((buf & mask) == (set & mask))
return 0;
buf = (buf & ~mask) | (set & mask);
ret = rv3029_eeprom_write(dev, reg, &buf, 1);
if (ret < 0)
return ret;
return 0;
}
static void rv3029_trickle_config(struct udevice *dev)
{
static const struct rv3029_trickle_tab_elem {
u32 r; /* resistance in ohms */
u8 conf; /* trickle config bits */
} rv3029_trickle_tab[] = {
{
.r = 1076,
.conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
}, {
.r = 1091,
.conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
RV3029_TRICKLE_20K,
}, {
.r = 1137,
.conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
RV3029_TRICKLE_80K,
}, {
.r = 1154,
.conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
}, {
.r = 1371,
.conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
RV3029_TRICKLE_80K,
}, {
.r = 1395,
.conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
}, {
.r = 1472,
.conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
}, {
.r = 1500,
.conf = RV3029_TRICKLE_1K,
}, {
.r = 3810,
.conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
RV3029_TRICKLE_80K,
}, {
.r = 4000,
.conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
}, {
.r = 4706,
.conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
}, {
.r = 5000,
.conf = RV3029_TRICKLE_5K,
}, {
.r = 16000,
.conf = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
}, {
.r = 20000,
.conf = RV3029_TRICKLE_20K,
}, {
.r = 80000,
.conf = RV3029_TRICKLE_80K,
},
};
int err;
u32 ohms;
u8 trickle_set_bits = 0;
/* Configure the trickle charger. */
err = dev_read_u32(dev, "trickle-resistor-ohms", &ohms);
if (!err) {
/* Find trickle-charger config */
for (int i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++)
if (rv3029_trickle_tab[i].r >= ohms) {
dev_dbg(dev, "trickle charger at %d ohms\n",
rv3029_trickle_tab[i].r);
trickle_set_bits = rv3029_trickle_tab[i].conf;
break;
}
}
dev_dbg(dev, "trickle charger config 0x%x\n", trickle_set_bits);
err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
RV3029_TRICKLE_MASK,
trickle_set_bits);
if (err < 0)
dev_dbg(dev, "failed to update trickle charger\n");
}
#else
static inline void rv3029_trickle_config(struct udevice *dev)
{
}
#endif
static int rv3029_probe(struct udevice *dev)
{
i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
DM_I2C_CHIP_WR_ADDRESS);
rv3029_trickle_config(dev);
return 0;
}
static const struct rtc_ops rv3029_rtc_ops = {
.get = rv3029_rtc_get,
.set = rv3029_rtc_set,
.read8 = rv3029_rtc_read8,
.write8 = rv3029_rtc_write8,
.reset = rv3029_rtc_reset,
};
static const struct udevice_id rv3029_rtc_ids[] = {
{ .compatible = "mc,rv3029" },
{ .compatible = "mc,rv3029c2" },
{ }
};
U_BOOT_DRIVER(rtc_rv3029) = {
.name = "rtc-rv3029",
.id = UCLASS_RTC,
.probe = rv3029_probe,
.of_match = rv3029_rtc_ids,
.ops = &rv3029_rtc_ops,
};
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