[PATCH] rtc: add ht1380 driver
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
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 23963271928a..eed48e35a578 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -220,4 +220,12 @@ config RTC_ZYNQMP Say "yes" here to support the on chip real time clock present on Xilinx ZynqMP SoC.
+config RTC_HT1380 + bool "Enable Holtek HT1380/HT1381 RTC driver" + depends on DM_RTC && DM_GPIO + help + Say "yes" here to get support for Holtek HT1380/HT1381 + Serial Timekeeper IC which provides seconds, minutes, hours, + day of the week, date, month and year information. + endmenu diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 009dd9d28c95..f3164782b605 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_RTC_DS3231) += ds3231.o obj-$(CONFIG_RTC_DS3232) += ds3232.o obj-$(CONFIG_RTC_EMULATION) += emul_rtc.o obj-$(CONFIG_RTC_FTRTC010) += ftrtc010.o +obj-$(CONFIG_RTC_HT1380) += ht1380.o obj-$(CONFIG_SANDBOX) += i2c_rtc_emul.o obj-$(CONFIG_RTC_IMXDI) += imxdi.o obj-$(CONFIG_RTC_ISL1208) += isl1208.o diff --git a/drivers/rtc/ht1380.c b/drivers/rtc/ht1380.c new file mode 100644 index 000000000000..25335227d893 --- /dev/null +++ b/drivers/rtc/ht1380.c @@ -0,0 +1,337 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Holtek HT1380/HT1381 Serial Timekeeper Chip + * + * Communication with the chip is vendor-specific. + * It is done via 3 GPIO pins: reset, clock, and data. + * Describe in .dts this way: + * + * rtc { + * compatible = "holtek,ht1380"; + * rst-gpio = <&gpio 19 GPIO_ACTIVE_LOW>; + * clk-gpio = <&gpio 20 GPIO_ACTIVE_HIGH>; + * dat-gpio = <&gpio 21 GPIO_ACTIVE_HIGH>; + * }; + * + */ + +#include <common.h> +#include <dm.h> +#include <rtc.h> +#include <bcd.h> +#include <asm/gpio.h> +#include <linux/delay.h> + +struct ht1380_priv { + struct gpio_desc rst_desc; + struct gpio_desc clk_desc; + struct gpio_desc dat_desc; +}; + +enum registers { + SEC, + MIN, + HOUR, + MDAY, + MONTH, + WDAY, + YEAR, + WP, + N_REGS +}; + +enum hour_mode { + AMPM_MODE = 0x80, /* RTC is in AM/PM mode */ + PM_NOW = 0x20, /* set if PM, clear if AM */ +}; + +static const int BURST = 0xbe; +static const int READ = 1; + +static void ht1380_half_period_delay(void) +{ + /* + * Delay for half a period. 1 us complies with the 500 KHz maximum + * input serial clock limit given by the datasheet. + */ + udelay(1); +} + +static int ht1380_send_byte(struct ht1380_priv *priv, int byte) +{ + int ret; + + for (int bit = 0; bit < 8; bit++) { + ret = dm_gpio_set_value(&priv->dat_desc, byte >> bit & 1); + if (ret) + break; + ht1380_half_period_delay(); + + ret = dm_gpio_set_value(&priv->clk_desc, 1); + if (ret) + break; + ht1380_half_period_delay(); + + ret = dm_gpio_set_value(&priv->clk_desc, 0); + if (ret) + break; + } + + return ret; +} + +/* + * Leave reset state. The transfer operation can then be started. + */ +static int ht1380_reset_off(struct ht1380_priv *priv) +{ + const unsigned int T_CC = 4; /* us, Reset to Clock Setup */ + int ret; + + /* + * Leave RESET state. + * Make sure we make the minimal delay required by the datasheet. + */ + ret = dm_gpio_set_value(&priv->rst_desc, 0); + udelay(T_CC); + + return ret; +} + +/* + * Enter reset state. Completes the transfer operation. + */ +static int ht1380_reset_on(struct ht1380_priv *priv) +{ + const unsigned int T_CWH = 4; /* us, Reset Inactive Time */ + int ret; + + /* + * Enter RESET state. + * Make sure we make the minimal delay required by the datasheet. + */ + ret = dm_gpio_set_value(&priv->rst_desc, 1); + udelay(T_CWH); + + return ret; +} + +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; + + 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; + + /* Correctness check: some registers are always non-zero */ + if (!reg[MDAY] || !reg[MONTH] || !reg[WDAY]) + goto exit; + + tm->tm_sec = bcd2bin(reg[SEC]); + tm->tm_min = bcd2bin(reg[MIN]); + if (reg[HOUR] & AMPM_MODE) { + /* AM-PM Mode, range is 01-12 */ + tm->tm_hour = bcd2bin(reg[HOUR] & 0x1f) % 12; + if (reg[HOUR] & PM_NOW) { + /* it is PM (otherwise AM) */ + tm->tm_hour += 12; + } + } else { + /* 24-hour Mode, range is 0-23 */ + tm->tm_hour = bcd2bin(reg[HOUR]); + } + tm->tm_mday = bcd2bin(reg[MDAY]); + tm->tm_mon = bcd2bin(reg[MONTH]); + tm->tm_year = 2000 + bcd2bin(reg[YEAR]); + tm->tm_wday = bcd2bin(reg[WDAY]) - 1; + tm->tm_yday = 0; + tm->tm_isdst = 0; + + ret = 0; + +exit: + ht1380_reset_on(priv); + + return ret; +} + +static int ht1380_write_protection_off(struct ht1380_priv *priv) +{ + int ret; + const int PROTECT = 0x8e; + + ret = ht1380_reset_off(priv); + if (ret) + return ret; + + ret = ht1380_send_byte(priv, PROTECT); + if (ret) + return ret; + ret = ht1380_send_byte(priv, 0); /* WP bit is 0 */ + if (ret) + return ret; + + return ht1380_reset_on(priv); +} + +static int ht1380_rtc_set(struct udevice *dev, const struct rtc_time *tm) +{ + struct ht1380_priv *priv = dev_get_priv(dev); + int ret, i, 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) + goto exit; + + ret = ht1380_write_protection_off(priv); + if (ret) + goto exit; + + reg[SEC] = bin2bcd(tm->tm_sec); + reg[MIN] = bin2bcd(tm->tm_min); + reg[HOUR] = bin2bcd(tm->tm_hour); + reg[MDAY] = bin2bcd(tm->tm_mday); + reg[MONTH] = bin2bcd(tm->tm_mon); + reg[WDAY] = bin2bcd(tm->tm_wday) + 1; + reg[YEAR] = bin2bcd(tm->tm_year - 2000); + reg[WP] = 0x80; /* WP bit is 1 */ + + ret = ht1380_reset_off(priv); + if (ret) + goto exit; + + ret = ht1380_send_byte(priv, BURST); + for (i = 0; i < N_REGS && ret; i++) + ret = ht1380_send_byte(priv, reg[i]); + +exit: + ht1380_reset_on(priv); + + return ret; +} + +static int ht1380_probe(struct udevice *dev) +{ + int ret; + struct ht1380_priv *priv; + + priv = dev_get_priv(dev); + if (!priv) + return -EINVAL; + + ret = gpio_request_by_name(dev, "rst-gpio", 0, + &priv->rst_desc, 0); + if (ret) + goto fail_rst; + + ret = gpio_request_by_name(dev, "clk-gpio", 0, + &priv->clk_desc, 0); + if (ret) + goto fail_clk; + + ret = gpio_request_by_name(dev, "dat-gpio", 0, + &priv->dat_desc, 0); + if (ret) + goto fail_dat; + + ret = dm_gpio_set_dir_flags(&priv->clk_desc, GPIOD_IS_OUT); + if (ret) + goto fail; + + ret = dm_gpio_set_dir_flags(&priv->rst_desc, GPIOD_IS_OUT); + if (ret) + goto fail; + + ret = ht1380_reset_on(priv); + if (ret) + goto fail; + + return 0; + +fail: + dm_gpio_free(dev, &priv->dat_desc); +fail_dat: + dm_gpio_free(dev, &priv->clk_desc); +fail_clk: + dm_gpio_free(dev, &priv->rst_desc); +fail_rst: + return ret; +} + +static int ht1380_remove(struct udevice *dev) +{ + struct ht1380_priv *priv = dev_get_priv(dev); + + dm_gpio_free(dev, &priv->rst_desc); + dm_gpio_free(dev, &priv->clk_desc); + dm_gpio_free(dev, &priv->dat_desc); + + return 0; +} + +static const struct rtc_ops ht1380_rtc_ops = { + .get = ht1380_rtc_get, + .set = ht1380_rtc_set, +}; + +static const struct udevice_id ht1380_rtc_ids[] = { + { .compatible = "holtek,ht1380" }, + { } +}; + +U_BOOT_DRIVER(rtc_ht1380) = { + .name = "rtc-ht1380", + .id = UCLASS_RTC, + .probe = ht1380_probe, + .remove = ht1380_remove, + .of_match = ht1380_rtc_ids, + .ops = &ht1380_rtc_ops, + .priv_auto = sizeof(struct ht1380_priv), +};
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
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 23963271928a..eed48e35a578 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -220,4 +220,12 @@ config RTC_ZYNQMP Say "yes" here to support the on chip real time clock present on Xilinx ZynqMP SoC.
+config RTC_HT1380
bool "Enable Holtek HT1380/HT1381 RTC driver"depends on DM_RTC && DM_GPIOhelpSay "yes" here to get support for Holtek HT1380/HT1381Serial Timekeeper IC which provides seconds, minutes, hours,day of the week, date, month and year information.
Perhaps mention how it is connected, i.e. three GPIOs.
endmenu diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 009dd9d28c95..f3164782b605 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_RTC_DS3231) += ds3231.o obj-$(CONFIG_RTC_DS3232) += ds3232.o obj-$(CONFIG_RTC_EMULATION) += emul_rtc.o obj-$(CONFIG_RTC_FTRTC010) += ftrtc010.o +obj-$(CONFIG_RTC_HT1380) += ht1380.o obj-$(CONFIG_SANDBOX) += i2c_rtc_emul.o obj-$(CONFIG_RTC_IMXDI) += imxdi.o obj-$(CONFIG_RTC_ISL1208) += isl1208.o diff --git a/drivers/rtc/ht1380.c b/drivers/rtc/ht1380.c new file mode 100644 index 000000000000..25335227d893 --- /dev/null +++ b/drivers/rtc/ht1380.c @@ -0,0 +1,337 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*
- Holtek HT1380/HT1381 Serial Timekeeper Chip
- Communication with the chip is vendor-specific.
- It is done via 3 GPIO pins: reset, clock, and data.
- Describe in .dts this way:
- rtc {
compatible = "holtek,ht1380";
rst-gpio = <&gpio 19 GPIO_ACTIVE_LOW>;
clk-gpio = <&gpio 20 GPIO_ACTIVE_HIGH>;
dat-gpio = <&gpio 21 GPIO_ACTIVE_HIGH>;
- };
Is there a binding file for this?
I believe the standard name should be rst-gpios (i.e. plural)?
- */
+#include <common.h> +#include <dm.h> +#include <rtc.h> +#include <bcd.h> +#include <asm/gpio.h> +#include <linux/delay.h>
+struct ht1380_priv {
struct gpio_desc rst_desc;struct gpio_desc clk_desc;struct gpio_desc dat_desc;+};
+enum registers {
SEC,MIN,HOUR,MDAY,MONTH,WDAY,YEAR,WP,N_REGS+};
+enum hour_mode {
AMPM_MODE = 0x80, /* RTC is in AM/PM mode */PM_NOW = 0x20, /* set if PM, clear if AM */+};
+static const int BURST = 0xbe; +static const int READ = 1;
+static void ht1380_half_period_delay(void) +{
/** Delay for half a period. 1 us complies with the 500 KHz maximum* input serial clock limit given by the datasheet.*/udelay(1);+}
+static int ht1380_send_byte(struct ht1380_priv *priv, int byte) +{
int ret;for (int bit = 0; bit < 8; bit++) {ret = dm_gpio_set_value(&priv->dat_desc, byte >> bit & 1);if (ret)break;ht1380_half_period_delay();ret = dm_gpio_set_value(&priv->clk_desc, 1);if (ret)break;ht1380_half_period_delay();ret = dm_gpio_set_value(&priv->clk_desc, 0);if (ret)break;}return ret;+}
+/*
- Leave reset state. The transfer operation can then be started.
- */
+static int ht1380_reset_off(struct ht1380_priv *priv) +{
const unsigned int T_CC = 4; /* us, Reset to Clock Setup */int ret;/** Leave RESET state.* Make sure we make the minimal delay required by the datasheet.*/ret = dm_gpio_set_value(&priv->rst_desc, 0);udelay(T_CC);return ret;+}
+/*
- Enter reset state. Completes the transfer operation.
- */
+static int ht1380_reset_on(struct ht1380_priv *priv) +{
const unsigned int T_CWH = 4; /* us, Reset Inactive Time */int ret;/** Enter RESET state.* Make sure we make the minimal delay required by the datasheet.*/ret = dm_gpio_set_value(&priv->rst_desc, 1);udelay(T_CWH);return ret;+}
+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?
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 ?
/* Correctness check: some registers are always non-zero */if (!reg[MDAY] || !reg[MONTH] || !reg[WDAY])goto exit;tm->tm_sec = bcd2bin(reg[SEC]);tm->tm_min = bcd2bin(reg[MIN]);if (reg[HOUR] & AMPM_MODE) {/* AM-PM Mode, range is 01-12 */tm->tm_hour = bcd2bin(reg[HOUR] & 0x1f) % 12;if (reg[HOUR] & PM_NOW) {/* it is PM (otherwise AM) */tm->tm_hour += 12;}} else {/* 24-hour Mode, range is 0-23 */tm->tm_hour = bcd2bin(reg[HOUR]);}tm->tm_mday = bcd2bin(reg[MDAY]);tm->tm_mon = bcd2bin(reg[MONTH]);tm->tm_year = 2000 + bcd2bin(reg[YEAR]);tm->tm_wday = bcd2bin(reg[WDAY]) - 1;tm->tm_yday = 0;tm->tm_isdst = 0;ret = 0;+exit:
ht1380_reset_on(priv);return ret;+}
+static int ht1380_write_protection_off(struct ht1380_priv *priv) +{
int ret;const int PROTECT = 0x8e;ret = ht1380_reset_off(priv);if (ret)return ret;ret = ht1380_send_byte(priv, PROTECT);if (ret)return ret;ret = ht1380_send_byte(priv, 0); /* WP bit is 0 */if (ret)return ret;return ht1380_reset_on(priv);+}
+static int ht1380_rtc_set(struct udevice *dev, const struct rtc_time *tm) +{
struct ht1380_priv *priv = dev_get_priv(dev);int ret, i, 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)goto exit;ret = ht1380_write_protection_off(priv);if (ret)goto exit;reg[SEC] = bin2bcd(tm->tm_sec);reg[MIN] = bin2bcd(tm->tm_min);reg[HOUR] = bin2bcd(tm->tm_hour);reg[MDAY] = bin2bcd(tm->tm_mday);reg[MONTH] = bin2bcd(tm->tm_mon);reg[WDAY] = bin2bcd(tm->tm_wday) + 1;reg[YEAR] = bin2bcd(tm->tm_year - 2000);reg[WP] = 0x80; /* WP bit is 1 */ret = ht1380_reset_off(priv);if (ret)goto exit;ret = ht1380_send_byte(priv, BURST);for (i = 0; i < N_REGS && ret; i++)ret = ht1380_send_byte(priv, reg[i]);+exit:
ht1380_reset_on(priv);return ret;+}
+static int ht1380_probe(struct udevice *dev) +{
int ret;struct ht1380_priv *priv;priv = dev_get_priv(dev);if (!priv)return -EINVAL;ret = gpio_request_by_name(dev, "rst-gpio", 0,&priv->rst_desc, 0);
You can pass GPIOD_IS_OUT as the last param and drop the extra code below.
if (ret)goto fail_rst;ret = gpio_request_by_name(dev, "clk-gpio", 0,&priv->clk_desc, 0);if (ret)goto fail_clk;ret = gpio_request_by_name(dev, "dat-gpio", 0,&priv->dat_desc, 0);if (ret)goto fail_dat;ret = dm_gpio_set_dir_flags(&priv->clk_desc, GPIOD_IS_OUT);if (ret)goto fail;ret = dm_gpio_set_dir_flags(&priv->rst_desc, GPIOD_IS_OUT);if (ret)goto fail;ret = ht1380_reset_on(priv);if (ret)goto fail;return 0;+fail:
dm_gpio_free(dev, &priv->dat_desc);+fail_dat:
dm_gpio_free(dev, &priv->clk_desc);+fail_clk:
dm_gpio_free(dev, &priv->rst_desc);+fail_rst:
return ret;+}
+static int ht1380_remove(struct udevice *dev) +{
struct ht1380_priv *priv = dev_get_priv(dev);dm_gpio_free(dev, &priv->rst_desc);dm_gpio_free(dev, &priv->clk_desc);dm_gpio_free(dev, &priv->dat_desc);return 0;+}
+static const struct rtc_ops ht1380_rtc_ops = {
.get = ht1380_rtc_get,.set = ht1380_rtc_set,+};
+static const struct udevice_id ht1380_rtc_ids[] = {
{ .compatible = "holtek,ht1380" },{ }+};
+U_BOOT_DRIVER(rtc_ht1380) = {
.name = "rtc-ht1380",.id = UCLASS_RTC,.probe = ht1380_probe,.remove = ht1380_remove,.of_match = ht1380_rtc_ids,.ops = &ht1380_rtc_ops,.priv_auto = sizeof(struct ht1380_priv),+};
2.34.1
Regards, Simon
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
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 23963271928a..eed48e35a578 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -220,4 +220,12 @@ config RTC_ZYNQMP Say "yes" here to support the on chip real time clock present on Xilinx ZynqMP SoC.
+config RTC_HT1380
bool "Enable Holtek HT1380/HT1381 RTC driver"depends on DM_RTC && DM_GPIOhelpSay "yes" here to get support for Holtek HT1380/HT1381Serial Timekeeper IC which provides seconds, minutes, hours,day of the week, date, month and year information.Perhaps mention how it is connected, i.e. three GPIOs.
endmenu diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 009dd9d28c95..f3164782b605 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_RTC_DS3231) += ds3231.o obj-$(CONFIG_RTC_DS3232) += ds3232.o obj-$(CONFIG_RTC_EMULATION) += emul_rtc.o obj-$(CONFIG_RTC_FTRTC010) += ftrtc010.o +obj-$(CONFIG_RTC_HT1380) += ht1380.o obj-$(CONFIG_SANDBOX) += i2c_rtc_emul.o obj-$(CONFIG_RTC_IMXDI) += imxdi.o obj-$(CONFIG_RTC_ISL1208) += isl1208.o diff --git a/drivers/rtc/ht1380.c b/drivers/rtc/ht1380.c new file mode 100644 index 000000000000..25335227d893 --- /dev/null +++ b/drivers/rtc/ht1380.c @@ -0,0 +1,337 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*
- Holtek HT1380/HT1381 Serial Timekeeper Chip
- Communication with the chip is vendor-specific.
- It is done via 3 GPIO pins: reset, clock, and data.
- Describe in .dts this way:
- rtc {
compatible = "holtek,ht1380";
rst-gpio = <&gpio 19 GPIO_ACTIVE_LOW>;
clk-gpio = <&gpio 20 GPIO_ACTIVE_HIGH>;
dat-gpio = <&gpio 21 GPIO_ACTIVE_HIGH>;
- };
Is there a binding file for this?
Not in the U-Boot repo yet. I am going to submit a .dts file binding to this driver. But I need to submit 2 more device drivers first. I guess, submitting .dts should be the final step.
I believe the standard name should be rst-gpios (i.e. plural)?
I grepped files in arch/arm/dts and it was not clear. There were more plural names however. So I can change it to plural in v3.
- */
+#include <common.h> +#include <dm.h> +#include <rtc.h> +#include <bcd.h> +#include <asm/gpio.h> +#include <linux/delay.h>
+struct ht1380_priv {
struct gpio_desc rst_desc;struct gpio_desc clk_desc;struct gpio_desc dat_desc;+};
+enum registers {
SEC,MIN,HOUR,MDAY,MONTH,WDAY,YEAR,WP,N_REGS+};
+enum hour_mode {
AMPM_MODE = 0x80, /* RTC is in AM/PM mode */PM_NOW = 0x20, /* set if PM, clear if AM */+};
+static const int BURST = 0xbe; +static const int READ = 1;
+static void ht1380_half_period_delay(void) +{
/** Delay for half a period. 1 us complies with the 500 KHz maximum* input serial clock limit given by the datasheet.*/udelay(1);+}
+static int ht1380_send_byte(struct ht1380_priv *priv, int byte) +{
int ret;for (int bit = 0; bit < 8; bit++) {ret = dm_gpio_set_value(&priv->dat_desc, byte >> bit & 1);if (ret)break;ht1380_half_period_delay();ret = dm_gpio_set_value(&priv->clk_desc, 1);if (ret)break;ht1380_half_period_delay();ret = dm_gpio_set_value(&priv->clk_desc, 0);if (ret)break;}return ret;+}
+/*
- Leave reset state. The transfer operation can then be started.
- */
+static int ht1380_reset_off(struct ht1380_priv *priv) +{
const unsigned int T_CC = 4; /* us, Reset to Clock Setup */int ret;/** Leave RESET state.* Make sure we make the minimal delay required by the datasheet.*/ret = dm_gpio_set_value(&priv->rst_desc, 0);udelay(T_CC);return ret;+}
+/*
- Enter reset state. Completes the transfer operation.
- */
+static int ht1380_reset_on(struct ht1380_priv *priv) +{
const unsigned int T_CWH = 4; /* us, Reset Inactive Time */int ret;/** Enter RESET state.* Make sure we make the minimal delay required by the datasheet.*/ret = dm_gpio_set_value(&priv->rst_desc, 1);udelay(T_CWH);return ret;+}
+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.
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 :).
/* Correctness check: some registers are always non-zero */if (!reg[MDAY] || !reg[MONTH] || !reg[WDAY])goto exit;tm->tm_sec = bcd2bin(reg[SEC]);tm->tm_min = bcd2bin(reg[MIN]);if (reg[HOUR] & AMPM_MODE) {/* AM-PM Mode, range is 01-12 */tm->tm_hour = bcd2bin(reg[HOUR] & 0x1f) % 12;if (reg[HOUR] & PM_NOW) {/* it is PM (otherwise AM) */tm->tm_hour += 12;}} else {/* 24-hour Mode, range is 0-23 */tm->tm_hour = bcd2bin(reg[HOUR]);}tm->tm_mday = bcd2bin(reg[MDAY]);tm->tm_mon = bcd2bin(reg[MONTH]);tm->tm_year = 2000 + bcd2bin(reg[YEAR]);tm->tm_wday = bcd2bin(reg[WDAY]) - 1;tm->tm_yday = 0;tm->tm_isdst = 0;ret = 0;+exit:
ht1380_reset_on(priv);return ret;+}
+static int ht1380_write_protection_off(struct ht1380_priv *priv) +{
int ret;const int PROTECT = 0x8e;ret = ht1380_reset_off(priv);if (ret)return ret;ret = ht1380_send_byte(priv, PROTECT);if (ret)return ret;ret = ht1380_send_byte(priv, 0); /* WP bit is 0 */if (ret)return ret;return ht1380_reset_on(priv);+}
+static int ht1380_rtc_set(struct udevice *dev, const struct rtc_time *tm) +{
struct ht1380_priv *priv = dev_get_priv(dev);int ret, i, 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)goto exit;ret = ht1380_write_protection_off(priv);if (ret)goto exit;reg[SEC] = bin2bcd(tm->tm_sec);reg[MIN] = bin2bcd(tm->tm_min);reg[HOUR] = bin2bcd(tm->tm_hour);reg[MDAY] = bin2bcd(tm->tm_mday);reg[MONTH] = bin2bcd(tm->tm_mon);reg[WDAY] = bin2bcd(tm->tm_wday) + 1;reg[YEAR] = bin2bcd(tm->tm_year - 2000);reg[WP] = 0x80; /* WP bit is 1 */ret = ht1380_reset_off(priv);if (ret)goto exit;ret = ht1380_send_byte(priv, BURST);for (i = 0; i < N_REGS && ret; i++)ret = ht1380_send_byte(priv, reg[i]);+exit:
ht1380_reset_on(priv);return ret;+}
+static int ht1380_probe(struct udevice *dev) +{
int ret;struct ht1380_priv *priv;priv = dev_get_priv(dev);if (!priv)return -EINVAL;ret = gpio_request_by_name(dev, "rst-gpio", 0,&priv->rst_desc, 0);You can pass GPIOD_IS_OUT as the last param and drop the extra code below.
Thanks! Did not know it.
if (ret)goto fail_rst;ret = gpio_request_by_name(dev, "clk-gpio", 0,&priv->clk_desc, 0);if (ret)goto fail_clk;ret = gpio_request_by_name(dev, "dat-gpio", 0,&priv->dat_desc, 0);if (ret)goto fail_dat;ret = dm_gpio_set_dir_flags(&priv->clk_desc, GPIOD_IS_OUT);if (ret)goto fail;ret = dm_gpio_set_dir_flags(&priv->rst_desc, GPIOD_IS_OUT);if (ret)goto fail;ret = ht1380_reset_on(priv);if (ret)goto fail;return 0;+fail:
dm_gpio_free(dev, &priv->dat_desc);+fail_dat:
dm_gpio_free(dev, &priv->clk_desc);+fail_clk:
dm_gpio_free(dev, &priv->rst_desc);+fail_rst:
return ret;+}
+static int ht1380_remove(struct udevice *dev) +{
struct ht1380_priv *priv = dev_get_priv(dev);dm_gpio_free(dev, &priv->rst_desc);dm_gpio_free(dev, &priv->clk_desc);dm_gpio_free(dev, &priv->dat_desc);return 0;+}
+static const struct rtc_ops ht1380_rtc_ops = {
.get = ht1380_rtc_get,.set = ht1380_rtc_set,+};
+static const struct udevice_id ht1380_rtc_ids[] = {
{ .compatible = "holtek,ht1380" },{ }+};
+U_BOOT_DRIVER(rtc_ht1380) = {
.name = "rtc-ht1380",.id = UCLASS_RTC,.probe = ht1380_probe,.remove = ht1380_remove,.of_match = ht1380_rtc_ids,.ops = &ht1380_rtc_ops,.priv_auto = sizeof(struct ht1380_priv),+};
2.34.1
Regards, Simon
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
On Thu, 8 Dec 2022 at 00:52, Simon Glass sjg@chromium.org wrote:
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>;
I2C transmits/receives bytes most significant bit first (msb), but this device needs lsb.
Hi Sergei,
On Fri, 9 Dec 2022 at 00:50, Sergei Antonov saproj@gmail.com wrote:
On Thu, 8 Dec 2022 at 00:52, Simon Glass sjg@chromium.org wrote:
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>;
I2C transmits/receives bytes most significant bit first (msb), but this device needs lsb.
Also it seems that it is not actually using the i2c protocol, even with that change.
Regards, Simon
On Tue, Dec 06, 2022 at 01:06:59PM +0300, Sergei Antonov 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
Please enable this on sandbox so that it gets build tested and not removed later as unused / dead code, thanks.
participants (3)
-
Sergei Antonov -
Simon Glass -
Tom Rini