Re: [PATCH 8/8] rtc: max77686: add MAX77714 support
From: Luca Ceresoli <luca@lucaceresoli.net>
Date: 2021-10-11 16:12:30
Also in:
linux-devicetree, linux-watchdog, lkml
Hi, see below for the issues with interrupt implementation that I mentioned in the cover letter. On 11/10/21 17:56, Luca Ceresoli wrote:
quoted hunk ↗ jump to hunk
The RTC included in the MAX77714 PMIC is very similar to the one in the MAX77686. Reuse the rtc-max77686.c driver with the minimum required changes for the MAX77714 RTC. Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net> --- drivers/rtc/Kconfig | 2 +- drivers/rtc/rtc-max77686.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+), 1 deletion(-)diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index e1bc5214494e..a73591ad292b 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig@@ -375,7 +375,7 @@ config RTC_DRV_MAX8997 config RTC_DRV_MAX77686 tristate "Maxim MAX77686" - depends on MFD_MAX77686 || MFD_MAX77620 || COMPILE_TEST + depends on MFD_MAX77686 || MFD_MAX77620 || MFD_MAX77714 || COMPILE_TEST help If you say yes here you will get support for the RTC of Maxim MAX77686/MAX77620/MAX77802 PMIC.diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c index 9901c596998a..e6564bc2171e 100644 --- a/drivers/rtc/rtc-max77686.c +++ b/drivers/rtc/rtc-max77686.c@@ -19,6 +19,7 @@ #define MAX77686_I2C_ADDR_RTC (0x0C >> 1) #define MAX77620_I2C_ADDR_RTC 0x68 +#define MAX77714_I2C_ADDR_RTC 0x48 #define MAX77686_INVALID_I2C_ADDR (-1) /* Define non existing register */@@ -203,6 +204,28 @@ static const struct max77686_rtc_driver_data max77686_drv_data = { .regmap_config = &max77686_rtc_regmap_config, }; +static const struct regmap_irq_chip max77714_rtc_irq_chip = { + .name = "max77714-rtc", + .status_base = MAX77686_RTC_INT, + .mask_base = MAX77686_RTC_INTM, + .num_regs = 1, + .irqs = max77686_rtc_irqs, + .num_irqs = ARRAY_SIZE(max77686_rtc_irqs) - 1, /* no WTSR on 77714 */ +}; + +static const struct max77686_rtc_driver_data max77714_drv_data = { + .delay = 16000, + .mask = 0x7f, + .map = max77686_map, + .alarm_enable_reg = false, + .rtc_irq_from_platform = false,
As far as I could understand, rtc_irq_from_platform should be 'true'.
This would trigger the 'if' branch in function
max77686_init_rtc_regmap() [0]:
if (info->drv_data->rtc_irq_from_platform) {
struct platform_device *pdev = to_platform_device(info->dev);
info->rtc_irq = platform_get_irq(pdev, 0);
if (info->rtc_irq < 0)
return info->rtc_irq;
} else {
info->rtc_irq = parent_i2c->irq;
}
Calling platform_get_irq() seems correct for the MAX77714, which can
generate various IRQ events, collecting them in a register, and raise a
single IRQ to the CPU via a physical pin.
However, if I set rtc_irq_from_platform = true, platform_get_irq()
returns IRQ number '1', which ends up in:
dummy 0-0048: Failed to request IRQ 1 for max77714-rtc: -22
max77686-rtc max77714-rtc: Failed to add RTC irq chip: -22
max77686-rtc: probe of max77714-rtc failed with error -22
I compared my code with other MFD drivers and their cell drivers (but
their datasheets is not available so I had to add some guesswork), and
couldn't find out where my code is wrong.
Unfortunately I have no IRQ access on my board (and I don't need them
for my use case). For this reason I initially thought of disabling all
the IRQ code in rtc-max77686.c via a new flag, but it would be quite
invasive and I wouldn't even be able to test that existing hardware
still works. Implementing a new RTC driver for the MAX77714 does not
seem to be a sane option as the hardware is really 99% equal to the
MAX77686 RTC.
Any suggestions on how to move on? -- Thanks!
[0]
https://elixir.bootlin.com/linux/latest/source/drivers/rtc/rtc-max77686.c#L676
Regards,
--
Luca