diff options
| author | Samuel Holland <samuel@sholland.org> | 2022-04-13 18:17:30 -0500 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2022-05-17 22:49:24 +0200 |
| commit | 581d6d8f483696ff164f52a71beb43a87b718592 (patch) | |
| tree | a7bc68b0707255ab94da6b3626cb85af881299fc /drivers/rtc | |
| parent | 3123109284176b1532874591f7c81f3837bbdc17 (diff) | |
| download | linux-581d6d8f483696ff164f52a71beb43a87b718592.tar.bz2 | |
rtc: sun6i: Add NVMEM provider
The sun6i RTC provides 32 bytes of general-purpose data registers.
They can be used to save data in the always-on RTC power domain.
The registers are writable via 32-bit MMIO accesses only.
Expose them with a NVMEM provider so they can be used by other drivers.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220413231731.56709-1-samuel@sholland.org
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-sun6i.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c index 5b3e4da63406..755aeb82a285 100644 --- a/drivers/rtc/rtc-sun6i.c +++ b/drivers/rtc/rtc-sun6i.c @@ -71,6 +71,10 @@ #define SUN6I_LOSC_OUT_GATING 0x0060 #define SUN6I_LOSC_OUT_GATING_EN_OFFSET 0 +/* General-purpose data */ +#define SUN6I_GP_DATA 0x0100 +#define SUN6I_GP_DATA_SIZE 0x20 + /* * Get date values */ @@ -662,6 +666,39 @@ static const struct rtc_class_ops sun6i_rtc_ops = { .alarm_irq_enable = sun6i_rtc_alarm_irq_enable }; +static int sun6i_rtc_nvmem_read(void *priv, unsigned int offset, void *_val, size_t bytes) +{ + struct sun6i_rtc_dev *chip = priv; + u32 *val = _val; + int i; + + for (i = 0; i < bytes / 4; ++i) + val[i] = readl(chip->base + SUN6I_GP_DATA + offset + 4 * i); + + return 0; +} + +static int sun6i_rtc_nvmem_write(void *priv, unsigned int offset, void *_val, size_t bytes) +{ + struct sun6i_rtc_dev *chip = priv; + u32 *val = _val; + int i; + + for (i = 0; i < bytes / 4; ++i) + writel(val[i], chip->base + SUN6I_GP_DATA + offset + 4 * i); + + return 0; +} + +static struct nvmem_config sun6i_rtc_nvmem_cfg = { + .type = NVMEM_TYPE_BATTERY_BACKED, + .reg_read = sun6i_rtc_nvmem_read, + .reg_write = sun6i_rtc_nvmem_write, + .size = SUN6I_GP_DATA_SIZE, + .word_size = 4, + .stride = 4, +}; + #ifdef CONFIG_PM_SLEEP /* Enable IRQ wake on suspend, to wake up from RTC. */ static int sun6i_rtc_suspend(struct device *dev) @@ -795,6 +832,11 @@ static int sun6i_rtc_probe(struct platform_device *pdev) if (ret) return ret; + sun6i_rtc_nvmem_cfg.priv = chip; + ret = devm_rtc_nvmem_register(chip->rtc, &sun6i_rtc_nvmem_cfg); + if (ret) + return ret; + dev_info(&pdev->dev, "RTC enabled\n"); return 0; |