[PATCH] rtc: add ht1380 driver
Support Holtek HT1380/HT1381 Serial Timekeeper Chip. Datasheet: https://www.holtek.com.tw/documents/10179/11842/ht1380_1v130.pdf
Signed-off-by: Sergei Antonov saproj@gmail.com --- drivers/rtc/Kconfig | 7 + drivers/rtc/Makefile | 1 + drivers/rtc/ht1380.c | 303 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 311 insertions(+) create mode 100644 drivers/rtc/ht1380.c
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 23963271928a..f62ee43b0f89 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -220,4 +220,11 @@ 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 Chip. + endmenu diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index d621be622848..d04ac8fb0938 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..af28b5f25fcd --- /dev/null +++ b/drivers/rtc/ht1380.c @@ -0,0 +1,303 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Holtek HT1380/HT1381 Serial Timekeeper Chip + */ + +#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 +}; + +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; +} + +static int ht1380_reset_off(struct ht1380_priv *priv) +{ + const unsigned int T_CC = 4; /* us, Reset to Clock Setup */ + int ret; + + /* Go out of RESET state. + Make sure we make the minimal delay required by the datasheet. */ + ret = dm_gpio_set_value(&priv->rst_desc, 1); + udelay(T_CC); + return ret; +} + +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, 0); + 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 > 0 */ + if (!reg[MDAY] || !reg[MONTH] || !reg[WDAY]) + goto exit; + + tm->tm_sec = bcd2bin(reg[SEC]); + tm->tm_min = bcd2bin(reg[MIN]); + if (reg[HOUR] & 0x80) { + /* AM-PM Mode, range is 01-12 */ + tm->tm_hour = bcd2bin(reg[HOUR] & 0x1F) % 12; + if (reg[HOUR] & 0x20) { + /* 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, 25 Oct 2022 at 08:24, Sergei Antonov saproj@gmail.com wrote:
Support Holtek HT1380/HT1381 Serial Timekeeper Chip. Datasheet: https://www.holtek.com.tw/documents/10179/11842/ht1380_1v130.pdf
Signed-off-by: Sergei Antonov saproj@gmail.com
drivers/rtc/Kconfig | 7 + drivers/rtc/Makefile | 1 + drivers/rtc/ht1380.c | 303 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 311 insertions(+) create mode 100644 drivers/rtc/ht1380.c
Looks good, just some minor things.
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 23963271928a..f62ee43b0f89 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -220,4 +220,11 @@ 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 Chip.
What features does it have? Needs a bit more detail.
endmenu diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index d621be622848..d04ac8fb0938 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..af28b5f25fcd --- /dev/null +++ b/drivers/rtc/ht1380.c @@ -0,0 +1,303 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*
- Holtek HT1380/HT1381 Serial Timekeeper Chip
- */
+#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+};
+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 maximuminput serial clock limit given by the datasheet. */
/* * Delay for half... * second line */
Please fix globally.
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;+}
+static int ht1380_reset_off(struct ht1380_priv *priv) +{
const unsigned int T_CC = 4; /* us, Reset to Clock Setup */int ret;/* Go out of RESET state.Make sure we make the minimal delay required by the datasheet. */ret = dm_gpio_set_value(&priv->rst_desc, 1);udelay(T_CC);
blank line before return
return ret;+}
+static int ht1380_reset_on(struct ht1380_priv *priv)
function comment - does it stay in reset state or automatically exit?
+{
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, 0);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;
Lower-case hex.
/* Correctness check: some registers are always > 0 */if (!reg[MDAY] || !reg[MONTH] || !reg[WDAY])goto exit;tm->tm_sec = bcd2bin(reg[SEC]);tm->tm_min = bcd2bin(reg[MIN]);if (reg[HOUR] & 0x80) {
I suggest having an enum or #define for 0x80 and the 0x20 below
/* AM-PM Mode, range is 01-12 */tm->tm_hour = bcd2bin(reg[HOUR] & 0x1F) % 12;if (reg[HOUR] & 0x20) {/* 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;
Define at top of file, e.g. in an enum
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),+};
2.34.1
Regards, Simon
On Wed, 26 Oct 2022 at 02:35, Simon Glass sjg@chromium.org wrote:
+static void ht1380_half_period_delay(void) +{
/* Delay for half a period. 1 us complies with the 500 KHz maximuminput serial clock limit given by the datasheet. *//*
- Delay for half...
- second line
*/
Please fix globally.
OK. I was confused by doc/develop/codingstyle.rst: * The exception for net files to the `multi-line comment https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting`_ applies only to Linux, not to U-Boot. What is the U-Boot style of multi-line comments remains a mystery to me.
+static int ht1380_reset_on(struct ht1380_priv *priv)
function comment - does it stay in reset state or automatically exit?
It stays in reset state. Until the counterpart function ht1380_reset_off is called.
/* Correctness check: some registers are always > 0 */if (!reg[MDAY] || !reg[MONTH] || !reg[WDAY])goto exit;tm->tm_sec = bcd2bin(reg[SEC]);tm->tm_min = bcd2bin(reg[MIN]);if (reg[HOUR] & 0x80) {I suggest having an enum or #define for 0x80 and the 0x20 below
Oh. I hoped so much for /* */ comments put after lines with 0x80 and 0x20.
/* AM-PM Mode, range is 01-12 */tm->tm_hour = bcd2bin(reg[HOUR] & 0x1F) % 12;if (reg[HOUR] & 0x20) {/* 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;Define at top of file, e.g. in an enum
What about locality of definitions?
Thanks for your quick comments.
On Wed, 26 Oct 2022 at 14:34, Sergei Antonov saproj@gmail.com wrote:
On Wed, 26 Oct 2022 at 02:35, Simon Glass sjg@chromium.org wrote:
+static void ht1380_half_period_delay(void) +{
/* Delay for half a period. 1 us complies with the 500 KHz maximuminput serial clock limit given by the datasheet. *//*
- Delay for half...
- second line
*/
Please fix globally.
OK. I was confused by doc/develop/codingstyle.rst:
- The exception for net files to the `multi-line comment
https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting`_ applies only to Linux, not to U-Boot. What is the U-Boot style of multi-line comments remains a mystery to me.
Tom, could you please clarify what is U-Boot style for multi-line comments? I can not draw it from doc/develop/codingstyle.rst
On Mon, Nov 21, 2022 at 05:47:16PM +0300, Sergei Antonov wrote:
On Wed, 26 Oct 2022 at 14:34, Sergei Antonov saproj@gmail.com wrote:
On Wed, 26 Oct 2022 at 02:35, Simon Glass sjg@chromium.org wrote:
+static void ht1380_half_period_delay(void) +{
/* Delay for half a period. 1 us complies with the 500 KHz maximuminput serial clock limit given by the datasheet. *//*
- Delay for half...
- second line
*/
Please fix globally.
OK. I was confused by doc/develop/codingstyle.rst:
- The exception for net files to the `multi-line comment
https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting`_ applies only to Linux, not to U-Boot. What is the U-Boot style of multi-line comments remains a mystery to me.
Tom, could you please clarify what is U-Boot style for multi-line comments? I can not draw it from doc/develop/codingstyle.rst
I'll make an attempt at re-wording the line there, but, per: https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting /* * It should be * like this. */
participants (3)
-
Sergei Antonov -
Simon Glass -
Tom Rini