Commit 581d6d8f authored by Samuel Holland's avatar Samuel Holland Committed by Alexandre Belloni
Browse files

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: default avatarSamuel Holland <samuel@sholland.org>
Acked-by: default avatarJernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220413231731.56709-1-samuel@sholland.org
parent 31231092

drivers/rtc/rtc-sun6i.c

+42 −0
Original line number Diff line number Diff line
@@ -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;