[U-Boot] [PATCH v2 2/2] rtc: Add DM support to ds1307

Simon Glass sjg at chromium.org
Sat Apr 29 00:27:59 UTC 2017


Hi Chris,

On 25 April 2017 at 23:19, Chris Packham <judge.packham at gmail.com> wrote:
> Add an implementation of the ds1307 driver that uses the driver model
> i2c APIs.
>
> Signed-off-by: Chris Packham <judge.packham at gmail.com>
>
> ---
>
> Changes in v2: None
>
>  drivers/rtc/Kconfig  |   7 ++
>  drivers/rtc/ds1307.c | 196 ++++++++++++++++++++++++++++++++++++++++++++++-----
>  2 files changed, 184 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index cb79a01..d06130c7 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -23,4 +23,11 @@ config RTC_PCF2127
>           has a selectable I2C-bus or SPI-bus, a backup battery switch-over circuit, a
>           programmable watchdog function, a timestamp function, and many other features.
>
> +config RTC_DS1307
> +       bool "Enable DS1307 driver"
> +       depends on DM_RTC
> +       help
> +         Support for Dallas Semiconductor (now Maxim) DS1307 and DS1338/9 and
> +         compatible Real Time Clock devices.
> +
>  endmenu
> diff --git a/drivers/rtc/ds1307.c b/drivers/rtc/ds1307.c
> index 3be1da6..68d1b65 100644
> --- a/drivers/rtc/ds1307.c
> +++ b/drivers/rtc/ds1307.c
> @@ -16,29 +16,12 @@
>
>  #include <common.h>
>  #include <command.h>
> +#include <dm.h>
>  #include <rtc.h>
>  #include <i2c.h>
>
>  #if defined(CONFIG_CMD_DATE)

Can that go in the Makefile?

>
> -/*---------------------------------------------------------------------*/
> -#undef DEBUG_RTC
> -
> -#ifdef DEBUG_RTC
> -#define DEBUGR(fmt,args...) printf(fmt ,##args)
> -#else
> -#define DEBUGR(fmt,args...)
> -#endif
> -/*---------------------------------------------------------------------*/
> -
> -#ifndef CONFIG_SYS_I2C_RTC_ADDR
> -# define CONFIG_SYS_I2C_RTC_ADDR       0x68
> -#endif
> -
> -#if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
> -# error The DS1307 is specified only up to 100kHz!
> -#endif
> -
>  /*
>   * RTC register addresses
>   */
> @@ -62,6 +45,26 @@
>  #define MCP7941X_BIT_ST                0x80
>  #define MCP7941X_BIT_VBATEN    0x08
>
> +#ifndef CONFIG_DM_RTC
> +
> +/*---------------------------------------------------------------------*/
> +#undef DEBUG_RTC
> +
> +#ifdef DEBUG_RTC
> +#define DEBUGR(fmt, args...) printf(fmt, ##args)
> +#else
> +#define DEBUGR(fmt, args...)
> +#endif
> +/*---------------------------------------------------------------------*/
> +
> +#ifndef CONFIG_SYS_I2C_RTC_ADDR
> +# define CONFIG_SYS_I2C_RTC_ADDR       0x68
> +#endif
> +
> +#if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
> +# error The DS1307 is specified only up to 100kHz!
> +#endif
> +
>  static uchar rtc_read (uchar reg);
>  static void rtc_write (uchar reg, uchar val);
>
> @@ -211,4 +214,159 @@ static void rtc_write (uchar reg, uchar val)
>  {
>         i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
>  }
> -#endif
> +
> +#else
> +static int ds1307_rtc_set(struct udevice *dev, const struct rtc_time *tm)
> +{
> +       int ret;
> +       uchar buf[7];
> +
> +       debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
> +             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 < 1970 || tm->tm_year > 2069)
> +               printf("WARNING: year should be between 1970 and 2069!\n");
> +
> +       buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
> +       buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
> +       buf[RTC_DAY_REG_ADDR] = bin2bcd(tm->tm_wday + 1);
> +       buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
> +       buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
> +       buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
> +       buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
> +
> +       if (of_device_is_compatible(dev, "microchip,mcp7941x")) {

Can you please use the data field in your compatible ID list instead
of checking this here?

> +               buf[RTC_DAY_REG_ADDR] |= MCP7941X_BIT_VBATEN;
> +               buf[RTC_SEC_REG_ADDR] |= MCP7941X_BIT_ST;
> +       }
> +
> +       ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
> +       if (ret < 0)
> +               return ret;
> +
> +       return 0;
> +}
> +
> +static int ds1307_rtc_get(struct udevice *dev, struct rtc_time *tm)
> +{
> +       int ret;
> +       uchar buf[7];
> +
> +read_rtc:
> +       ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
> +       if (ret < 0)
> +               return ret;
> +
> +       if (of_device_is_compatible(dev, "dallas,ds1307")) {

Same with this

> +               if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
> +                       printf("### Warning: RTC oscillator has stopped\n");
> +                       /* clear the CH flag */
> +                       buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
> +                       dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
> +                                        buf[RTC_SEC_REG_ADDR]);
> +                       return -1;
> +               }
> +       }
> +
> +       if (of_device_is_compatible(dev, "dallas,mcp7941x")) {
> +               /* make sure that the backup battery is enabled */
> +               if (!(buf[RTC_DAY_REG_ADDR] & MCP7941X_BIT_VBATEN)) {
> +                       dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR,
> +                                        buf[RTC_DAY_REG_ADDR] |
> +                                        MCP7941X_BIT_VBATEN);
> +               }
> +
> +               /* clock halted?  turn it on, so clock can tick. */
> +               if (!(buf[RTC_SEC_REG_ADDR] & MCP7941X_BIT_ST)) {
> +                       dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
> +                                        MCP7941X_BIT_ST);
> +                       printf("Started RTC\n");
> +                       goto read_rtc;
> +               }
> +       }
> +
> +       tm->tm_sec  = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
> +       tm->tm_min  = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
> +       tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
> +       tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
> +       tm->tm_mon  = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
> +       tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) +
> +                             (bcd2bin(buf[RTC_YR_REG_ADDR]) >= 70 ?
> +                              1900 : 2000);
> +       tm->tm_wday = bcd2bin((buf[RTC_DAY_REG_ADDR] - 1) & 0x07);
> +       tm->tm_yday = 0;
> +       tm->tm_isdst = 0;
> +
> +       debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
> +             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 ds1307_rtc_reset(struct udevice *dev)
> +{
> +       int ret;
> +       struct rtc_time tmp = {
> +               .tm_year = 1970,
> +               .tm_mon = 1,
> +               .tm_mday = 1,
> +               .tm_hour = 0,
> +               .tm_min = 0,
> +               .tm_sec = 0,
> +       };
> +
> +       /* clear Clock Halt */
> +       ret = dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 0x00);
> +       if (ret < 0)
> +               return ret;
> +       ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
> +                              RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 |
> +                              RTC_CTL_BIT_RS0);
> +       if (ret < 0)
> +               return ret;
> +
> +       ret = ds1307_rtc_set(dev, &tmp);
> +       if (ret < 0)
> +               return ret;
> +
> +       debug("RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
> +             tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
> +             tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
> +
> +       return 0;
> +}
> +
> +static int ds1307_probe(struct udevice *dev)
> +{
> +       i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
> +                          DM_I2C_CHIP_WR_ADDRESS);
> +
> +       return 0;
> +}
> +
> +static const struct rtc_ops ds1307_rtc_ops = {
> +       .get = ds1307_rtc_get,
> +       .set = ds1307_rtc_set,
> +       .reset = ds1307_rtc_reset,
> +};
> +
> +static const struct udevice_id ds1307_rtc_ids[] = {
> +       { .compatible = "dallas,ds1307" },
> +       { .compatible = "dallas,ds1337" },
> +       { .compatible = "dallas,ds1340" },
> +       { .compatible = "microchip,mcp7941x" },

Here you can add a .data field to each, using an enum for the
different values, and save it in some private data. See ns16550.c for
an example.

> +       { }
> +};
> +
> +U_BOOT_DRIVER(rtc_ds1307) = {
> +       .name   = "rtc-ds1307",
> +       .id     = UCLASS_RTC,
> +       .probe  = ds1307_probe,
> +       .of_match = ds1307_rtc_ids,
> +       .ops    = &ds1307_rtc_ops,
> +};
> +#endif /* CONFIG_DM_RTC */
> +
> +#endif /* CONFIG_CMD_DATE*/
> --
> 2.10.1
>

Regards,
Simon


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