Hi Sergei,
On Thu, 8 Dec 2022 at 06:09, Sergei Antonov saproj@gmail.com wrote:
On Wed, 7 Dec 2022 at 04:08, Simon Glass sjg@chromium.org wrote:
Hi Sergei,
On Tue, 6 Dec 2022 at 23:07, Sergei Antonov saproj@gmail.com wrote:
Support Holtek HT1380/HT1381 Serial Timekeeper Chip. It provides seconds , minutes, hours, day of the week, date, month and year information.
Datasheet: https://www.holtek.com.tw/documents/10179/11842/ht1380_1v130.pdf
Signed-off-by: Sergei Antonov saproj@gmail.com
v2:
- The RESET pin is now to be described as ACTIVE_LOW in dts.
Changes suggested by Simon Glass:
- a more detailed driver description in Kconfig
- multi-line comments' style
- enum for 0x80 and the 0x20 at top of file
- lower-case hex constants
- function comments for ht1380_reset_on/off
- blank line before returns
PROTECT remains in a function scope for the sake of locality of definitions.
drivers/rtc/Kconfig | 8 + drivers/rtc/Makefile | 1 + drivers/rtc/ht1380.c | 337 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 346 insertions(+) create mode 100644 drivers/rtc/ht1380.c
[..]
+static int ht1380_rtc_get(struct udevice *dev, struct rtc_time *tm) +{
struct ht1380_priv *priv = dev_get_priv(dev);int ret, i, bit, reg[N_REGS];ret = dm_gpio_set_value(&priv->clk_desc, 0);if (ret)return ret;ret = dm_gpio_set_dir_flags(&priv->dat_desc, GPIOD_IS_OUT);if (ret)return ret;ret = ht1380_reset_off(priv);if (ret)goto exit;ret = ht1380_send_byte(priv, BURST + READ);if (ret)goto exit;ret = dm_gpio_set_dir_flags(&priv->dat_desc, GPIOD_IS_IN);if (ret)goto exit;Is this some sort of I2C protocol?
Like I2C it uses a pin for clock and a pin for data in/out. Unlike I2C it does not use addressing. I am not sure whether this driver can utilize some of the existing I2C code in U-Boot. Wrote my own bit banging routines.
Yes you can use i2c, by setting the offset_len to 0, e.g. with:
u-boot,i2c-offset-len = <0>;
for (i = 0; i < N_REGS; i++) {reg[i] = 0;for (bit = 0; bit < 8; bit++) {ht1380_half_period_delay();ret = dm_gpio_set_value(&priv->clk_desc, 1);if (ret)goto exit;ht1380_half_period_delay();reg[i] |= dm_gpio_get_value(&priv->dat_desc) << bit;ret = dm_gpio_set_value(&priv->clk_desc, 0);if (ret)goto exit;}}ret = -EINVAL;/* Correctness check: some bits are always zero */if ((reg[MIN] & 0x80) || (reg[HOUR] & 0x40) || (reg[MDAY] & 0xc0) ||(reg[MONTH] & 0xe0) || (reg[WDAY] & 0xf8) || (reg[WP] & 0x7f))goto exit;Drop extra brackets ?
OK. Will be done in v3. I put extra brackets expecting reviewers to criticize code readability :).
:)
Regards, Simon