rtc: davinci: add driver model support

Update the driver to support the device tree and the driver model.
The read / write helpers in rtc_ops allow access to scratch registers
only. The offset parameter is added to the address of the scratch0
register.

Support for non-DM has been removed as there were no users.

Signed-off-by: Dario Binacchi <dariobin@libero.it>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Link: https://lore.kernel.org/r/20210602203805.11494-8-dariobin@libero.it

1 files changed, 367 insertions, 61 deletions

diff --git a/drivers/rtc/davinci.c b/drivers/rtc/davinci.c
index 82e5eb3b43..21e5234477 100644
--- a/drivers/rtc/davinci.c
+++ b/drivers/rtc/davinci.c
@@ -2,127 +2,433 @@
 /*
  * (C) Copyright 2011 DENX Software Engineering GmbH
  * Heiko Schocher <hs@denx.de>
+ * Copyright (C) 2021 Dario Binacchi <dariobin@libero.it>
  */
 #include <common.h>
 #include <command.h>
+#include <dm.h>
+#include <clk.h>
 #include <log.h>
 #include <rtc.h>
 #include <asm/io.h>
-#include <asm/davinci_rtc.h>
-#include <asm/arch/hardware.h>
+#include <dm/device_compat.h>
 #include <linux/delay.h>
 
-#if !defined(RTC_BASE) && defined(DAVINCI_RTC_BASE)
-#define RTC_BASE DAVINCI_RTC_BASE
-#endif
+/* RTC registers */
+#define OMAP_RTC_SECONDS_REG		0x00
+#define OMAP_RTC_MINUTES_REG		0x04
+#define OMAP_RTC_HOURS_REG		0x08
+#define OMAP_RTC_DAYS_REG		0x0C
+#define OMAP_RTC_MONTHS_REG		0x10
+#define OMAP_RTC_YEARS_REG		0x14
+#define OMAP_RTC_WEEKS_REG		0x18
 
-static void davinci_rtc_lock(struct davinci_rtc *rtc)
+#define OMAP_RTC_CTRL_REG		0x40
+#define OMAP_RTC_STATUS_REG		0x44
+#define OMAP_RTC_INTERRUPTS_REG		0x48
+
+#define OMAP_RTC_OSC_REG		0x54
+
+#define OMAP_RTC_SCRATCH0_REG		0x60
+#define OMAP_RTC_SCRATCH1_REG		0x64
+#define OMAP_RTC_SCRATCH2_REG		0x68
+
+#define OMAP_RTC_KICK0_REG		0x6c
+#define OMAP_RTC_KICK1_REG		0x70
+
+#define OMAP_RTC_PMIC_REG		0x98
+
+/* OMAP_RTC_CTRL_REG bit fields: */
+#define OMAP_RTC_CTRL_SPLIT		BIT(7)
+#define OMAP_RTC_CTRL_DISABLE		BIT(6)
+#define OMAP_RTC_CTRL_SET_32_COUNTER	BIT(5)
+#define OMAP_RTC_CTRL_TEST		BIT(4)
+#define OMAP_RTC_CTRL_MODE_12_24	BIT(3)
+#define OMAP_RTC_CTRL_AUTO_COMP		BIT(2)
+#define OMAP_RTC_CTRL_ROUND_30S		BIT(1)
+#define OMAP_RTC_CTRL_STOP		BIT(0)
+
+/* OMAP_RTC_STATUS_REG bit fields */
+#define OMAP_RTC_STATUS_POWER_UP	BIT(7)
+#define OMAP_RTC_STATUS_ALARM2		BIT(7)
+#define OMAP_RTC_STATUS_ALARM		BIT(6)
+#define OMAP_RTC_STATUS_1D_EVENT	BIT(5)
+#define OMAP_RTC_STATUS_1H_EVENT	BIT(4)
+#define OMAP_RTC_STATUS_1M_EVENT	BIT(3)
+#define OMAP_RTC_STATUS_1S_EVENT	BIT(2)
+#define OMAP_RTC_STATUS_RUN		BIT(1)
+#define OMAP_RTC_STATUS_BUSY		BIT(0)
+
+/* OMAP_RTC_OSC_REG bit fields */
+#define OMAP_RTC_OSC_32KCLK_EN		BIT(6)
+#define OMAP_RTC_OSC_SEL_32KCLK_SRC	BIT(3)
+#define OMAP_RTC_OSC_OSC32K_GZ_DISABLE	BIT(4)
+
+/* OMAP_RTC_KICKER values */
+#define	OMAP_RTC_KICK0_VALUE		0x83e70b13
+#define	OMAP_RTC_KICK1_VALUE		0x95a4f1e0
+
+struct omap_rtc_device_type {
+	bool has_32kclk_en;
+	bool has_irqwakeen;
+	bool has_pmic_mode;
+	bool has_power_up_reset;
+};
+
+struct omap_rtc_priv {
+	fdt_addr_t base;
+	u8 max_reg;
+	struct udevice *dev;
+	struct clk clk;
+	bool has_ext_clk;
+	const struct omap_rtc_device_type *type;
+};
+
+static inline u8 omap_rtc_readb(struct omap_rtc_priv *priv, unsigned int reg)
+{
+	return readb(priv->base + reg);
+}
+
+static inline u32 omap_rtc_readl(struct omap_rtc_priv *priv, unsigned int reg)
+{
+	return readl(priv->base + reg);
+}
+
+static inline void omap_rtc_writeb(struct omap_rtc_priv *priv, unsigned int reg,
+				   u8 val)
+{
+	writeb(val, priv->base + reg);
+}
+
+static inline void omap_rtc_writel(struct omap_rtc_priv *priv, unsigned int reg,
+				   u32 val)
+{
+	writel(val, priv->base + reg);
+}
+
+static inline void omap_rtc_unlock(struct omap_rtc_priv *priv)
 {
-	writel(0, &rtc->kick0r);
-	writel(0, &rtc->kick1r);
+	omap_rtc_writel(priv, OMAP_RTC_KICK0_REG, OMAP_RTC_KICK0_VALUE);
+	omap_rtc_writel(priv, OMAP_RTC_KICK1_REG, OMAP_RTC_KICK1_VALUE);
 }
 
-static void davinci_rtc_unlock(struct davinci_rtc *rtc)
+static inline void omap_rtc_lock(struct omap_rtc_priv *priv)
 {
-	writel(RTC_KICK0R_WE, &rtc->kick0r);
-	writel(RTC_KICK1R_WE, &rtc->kick1r);
+	omap_rtc_writel(priv, OMAP_RTC_KICK0_REG, 0);
+	omap_rtc_writel(priv, OMAP_RTC_KICK1_REG, 0);
 }
 
-static int davinci_rtc_wait_not_busy(struct davinci_rtc *rtc)
+static int omap_rtc_wait_not_busy(struct omap_rtc_priv *priv)
 {
 	int count;
 	u8 status;
 
-	status = readb(&rtc->status);
-	if ((status & RTC_STATE_RUN) != RTC_STATE_RUN) {
+	status = omap_rtc_readb(priv, OMAP_RTC_STATUS_REG);
+	if ((status & OMAP_RTC_STATUS_RUN) != OMAP_RTC_STATUS_RUN) {
 		printf("RTC doesn't run\n");
 		return -1;
 	}
 
 	/* BUSY may stay active for 1/32768 second (~30 usec) */
 	for (count = 0; count < 50; count++) {
-		if (!(status & RTC_STATE_BUSY))
+		if (!(status & OMAP_RTC_STATUS_BUSY))
 			break;
 
 		udelay(1);
-		status = readb(&rtc->status);
+		status = omap_rtc_readb(priv, OMAP_RTC_STATUS_REG);
 	}
 
 	/* now we have ~15 usec to read/write various registers */
 	return 0;
 }
 
-int rtc_get(struct rtc_time *tmp)
+static int omap_rtc_reset(struct udevice *dev)
+{
+	struct omap_rtc_priv *priv = dev_get_priv(dev);
+
+	/* run RTC counter */
+	omap_rtc_writeb(priv, OMAP_RTC_CTRL_REG, 0x01);
+	return 0;
+}
+
+static int omap_rtc_set(struct udevice *dev, const struct rtc_time *tm)
+{
+	struct omap_rtc_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = omap_rtc_wait_not_busy(priv);
+	if (ret)
+		return ret;
+
+	omap_rtc_unlock(priv);
+	omap_rtc_writeb(priv, OMAP_RTC_YEARS_REG, bin2bcd(tm->tm_year % 100));
+	omap_rtc_writeb(priv, OMAP_RTC_MONTHS_REG, bin2bcd(tm->tm_mon));
+	omap_rtc_writeb(priv, OMAP_RTC_WEEKS_REG, bin2bcd(tm->tm_wday));
+	omap_rtc_writeb(priv, OMAP_RTC_DAYS_REG, bin2bcd(tm->tm_mday));
+	omap_rtc_writeb(priv, OMAP_RTC_HOURS_REG, bin2bcd(tm->tm_hour));
+	omap_rtc_writeb(priv, OMAP_RTC_MINUTES_REG, bin2bcd(tm->tm_min));
+	omap_rtc_writeb(priv, OMAP_RTC_SECONDS_REG, bin2bcd(tm->tm_sec));
+	omap_rtc_lock(priv);
+
+	dev_dbg(dev, "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
+		tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, tm->tm_hour,
+		tm->tm_min, tm->tm_sec);
+
+	return 0;
+}
+
+static int omap_rtc_get(struct udevice *dev, struct rtc_time *tm)
 {
-	struct davinci_rtc *rtc = (struct davinci_rtc *)RTC_BASE;
+	struct omap_rtc_priv *priv = dev_get_priv(dev);
 	unsigned long sec, min, hour, mday, wday, mon_cent, year;
 	int ret;
 
-	ret = davinci_rtc_wait_not_busy(rtc);
+	ret = omap_rtc_wait_not_busy(priv);
 	if (ret)
 		return ret;
 
-	sec	= readb(&rtc->second);
-	min	= readb(&rtc->minutes);
-	hour	= readb(&rtc->hours);
-	mday	= readb(&rtc->day);
-	wday	= readb(&rtc->dotw);
-	mon_cent = readb(&rtc->month);
-	year	= readb(&rtc->year);
+	sec = omap_rtc_readb(priv, OMAP_RTC_SECONDS_REG);
+	min = omap_rtc_readb(priv, OMAP_RTC_MINUTES_REG);
+	hour = omap_rtc_readb(priv, OMAP_RTC_HOURS_REG);
+	mday = omap_rtc_readb(priv, OMAP_RTC_DAYS_REG);
+	wday = omap_rtc_readb(priv, OMAP_RTC_WEEKS_REG);
+	mon_cent = omap_rtc_readb(priv, OMAP_RTC_MONTHS_REG);
+	year = omap_rtc_readb(priv, OMAP_RTC_YEARS_REG);
 
-	debug("Get RTC year: %02lx mon/cent: %02lx mday: %02lx wday: %02lx "
+	dev_dbg(dev,
+		"Get RTC year: %02lx mon/cent: %02lx mday: %02lx wday: %02lx "
 		"hr: %02lx min: %02lx sec: %02lx\n",
 		year, mon_cent, mday, wday,
 		hour, min, sec);
 
-	tmp->tm_sec  = bcd2bin(sec  & 0x7F);
-	tmp->tm_min  = bcd2bin(min  & 0x7F);
-	tmp->tm_hour = bcd2bin(hour & 0x3F);
-	tmp->tm_mday = bcd2bin(mday & 0x3F);
-	tmp->tm_mon  = bcd2bin(mon_cent & 0x1F);
-	tmp->tm_year = bcd2bin(year) + 2000;
-	tmp->tm_wday = bcd2bin(wday & 0x07);
-	tmp->tm_yday = 0;
-	tmp->tm_isdst = 0;
+	tm->tm_sec  = bcd2bin(sec  & 0x7F);
+	tm->tm_min  = bcd2bin(min  & 0x7F);
+	tm->tm_hour = bcd2bin(hour & 0x3F);
+	tm->tm_mday = bcd2bin(mday & 0x3F);
+	tm->tm_mon  = bcd2bin(mon_cent & 0x1F);
+	tm->tm_year = bcd2bin(year) + 2000;
+	tm->tm_wday = bcd2bin(wday & 0x07);
+	tm->tm_yday = 0;
+	tm->tm_isdst = 0;
 
-	debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
-		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
-		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
+	dev_dbg(dev, "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
+		tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, tm->tm_hour,
+		tm->tm_min, tm->tm_sec);
 
 	return 0;
 }
 
-int rtc_set(struct rtc_time *tmp)
+static int omap_rtc_scratch_read(struct udevice *dev, uint offset,
+				 u8 *buffer, uint len)
 {
-	struct davinci_rtc *rtc = (struct davinci_rtc *)RTC_BASE;
-	int ret;
+	struct omap_rtc_priv *priv = dev_get_priv(dev);
+	u32 *val = (u32 *)buffer;
+	unsigned int reg;
+	int i;
 
-	ret = davinci_rtc_wait_not_busy(rtc);
-	if (ret)
-		return ret;
+	if (len & 3)
+		return -EFAULT;
+
+	for (i = 0; i < len / 4; i++) {
+		reg = OMAP_RTC_SCRATCH0_REG + offset + (i * 4);
+		if (reg >= OMAP_RTC_KICK0_REG)
+			return -EFAULT;
+
+		val[i] = omap_rtc_readl(priv, reg);
+	}
+
+	return 0;
+}
+
+static int omap_rtc_scratch_write(struct udevice *dev, uint offset,
+				  const u8 *buffer, uint len)
+{
+	struct omap_rtc_priv *priv = dev_get_priv(dev);
+	u32 *val = (u32 *)buffer;
+	unsigned int reg;
+	int i;
 
-	davinci_rtc_unlock(rtc);
-	writeb(bin2bcd(tmp->tm_year % 100), &rtc->year);
-	writeb(bin2bcd(tmp->tm_mon), &rtc->month);
+	if (len & 3)
+		return -EFAULT;
 
-	writeb(bin2bcd(tmp->tm_wday), &rtc->dotw);
-	writeb(bin2bcd(tmp->tm_mday), &rtc->day);
-	writeb(bin2bcd(tmp->tm_hour), &rtc->hours);
-	writeb(bin2bcd(tmp->tm_min), &rtc->minutes);
-	writeb(bin2bcd(tmp->tm_sec), &rtc->second);
-	davinci_rtc_lock(rtc);
+	omap_rtc_unlock(priv);
+	for (i = 0; i < len / 4; i++) {
+		reg = OMAP_RTC_SCRATCH0_REG + offset + (i * 4);
+		if (reg >= OMAP_RTC_KICK0_REG)
+			return -EFAULT;
 
-	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
-	      tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
-	      tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
+		omap_rtc_writel(priv, reg, val[i]);
+	}
+	omap_rtc_lock(priv);
 
 	return 0;
 }
 
-void rtc_reset(void)
+static int omap_rtc_remove(struct udevice *dev)
 {
-	struct davinci_rtc *rtc = (struct davinci_rtc *)RTC_BASE;
+	struct omap_rtc_priv *priv = dev_get_priv(dev);
+	u8 reg;
 
-	/* run RTC counter */
-	writeb(0x01, &rtc->ctrl);
+	if (priv->clk.dev)
+		clk_disable(&priv->clk);
+
+	omap_rtc_unlock(priv);
+
+	/* leave rtc running, but disable irqs */
+	omap_rtc_writeb(priv, OMAP_RTC_INTERRUPTS_REG, 0);
+
+	if (priv->has_ext_clk) {
+		reg = omap_rtc_readb(priv, OMAP_RTC_OSC_REG);
+		reg &= ~OMAP_RTC_OSC_SEL_32KCLK_SRC;
+		omap_rtc_writeb(priv, OMAP_RTC_OSC_REG, reg);
+	}
+
+	omap_rtc_lock(priv);
+	return 0;
+}
+
+static int omap_rtc_probe(struct udevice *dev)
+{
+	struct omap_rtc_priv *priv = dev_get_priv(dev);
+	u8 reg, mask, new_ctrl;
+
+	priv->dev = dev;
+	priv->type = (struct omap_rtc_device_type *)dev_get_driver_data(dev);
+	priv->max_reg = OMAP_RTC_PMIC_REG;
+
+	if (!clk_get_by_name(dev, "ext-clk", &priv->clk))
+		priv->has_ext_clk = true;
+	else
+		clk_get_by_name(dev, "int-clk", &priv->clk);
+
+	if (priv->clk.dev)
+		clk_enable(&priv->clk);
+	else
+		dev_warn(dev, "missing clock\n");
+
+	omap_rtc_unlock(priv);
+
+	/*
+	 * disable interrupts
+	 *
+	 * NOTE: ALARM2 is not cleared on AM3352 if rtc_write (writeb) is used
+	 */
+	omap_rtc_writel(priv, OMAP_RTC_INTERRUPTS_REG, 0);
+
+	if (priv->type->has_32kclk_en) {
+		reg = omap_rtc_readb(priv, OMAP_RTC_OSC_REG);
+		omap_rtc_writeb(priv, OMAP_RTC_OSC_REG,
+				reg | OMAP_RTC_OSC_32KCLK_EN);
+	}
+
+	/* clear old status */
+	reg = omap_rtc_readb(priv, OMAP_RTC_STATUS_REG);
+
+	mask = OMAP_RTC_STATUS_ALARM;
+
+	if (priv->type->has_pmic_mode)
+		mask |= OMAP_RTC_STATUS_ALARM2;
+
+	if (priv->type->has_power_up_reset) {
+		mask |= OMAP_RTC_STATUS_POWER_UP;
+		if (reg & OMAP_RTC_STATUS_POWER_UP)
+			dev_info(dev, "RTC power up reset detected\n");
+	}
+
+	if (reg & mask)
+		omap_rtc_writeb(priv, OMAP_RTC_STATUS_REG, reg & mask);
+
+	/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
+	reg = omap_rtc_readb(priv, OMAP_RTC_CTRL_REG);
+	if (reg & OMAP_RTC_CTRL_STOP)
+		dev_info(dev, "already running\n");
+
+	/* force to 24 hour mode */
+	new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT | OMAP_RTC_CTRL_AUTO_COMP);
+	new_ctrl |= OMAP_RTC_CTRL_STOP;
+
+	/*
+	 * BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
+	 *
+	 *  - Device wake-up capability setting should come through chip
+	 *    init logic. OMAP1 boards should initialize the "wakeup capable"
+	 *    flag in the platform device if the board is wired right for
+	 *    being woken up by RTC alarm. For OMAP-L138, this capability
+	 *    is built into the SoC by the "Deep Sleep" capability.
+	 *
+	 *  - Boards wired so RTC_ON_nOFF is used as the reset signal,
+	 *    rather than nPWRON_RESET, should forcibly enable split
+	 *    power mode.  (Some chip errata report that RTC_CTRL_SPLIT
+	 *    is write-only, and always reads as zero...)
+	 */
+
+	if (new_ctrl & OMAP_RTC_CTRL_SPLIT)
+		dev_info(dev, "split power mode\n");
+
+	if (reg != new_ctrl)
+		omap_rtc_writeb(priv, OMAP_RTC_CTRL_REG, new_ctrl);
+
+	/*
+	 * If we have the external clock then switch to it so we can keep
+	 * ticking across suspend.
+	 */
+	if (priv->has_ext_clk) {
+		reg = omap_rtc_readb(priv, OMAP_RTC_OSC_REG);
+		reg &= ~OMAP_RTC_OSC_OSC32K_GZ_DISABLE;
+		reg |= OMAP_RTC_OSC_32KCLK_EN | OMAP_RTC_OSC_SEL_32KCLK_SRC;
+		omap_rtc_writeb(priv, OMAP_RTC_OSC_REG, reg);
+	}
+
+	omap_rtc_lock(priv);
+	return 0;
 }
+
+static int omap_rtc_of_to_plat(struct udevice *dev)
+{
+	struct omap_rtc_priv *priv = dev_get_priv(dev);
+
+	priv->base = dev_read_addr(dev);
+	if (priv->base == FDT_ADDR_T_NONE) {
+		dev_err(dev, "invalid address\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "base=%pa\n", &priv->base);
+	return 0;
+}
+
+static const struct rtc_ops omap_rtc_ops = {
+	.get = omap_rtc_get,
+	.set = omap_rtc_set,
+	.reset = omap_rtc_reset,
+	.read = omap_rtc_scratch_read,
+	.write = omap_rtc_scratch_write,
+};
+
+static const struct omap_rtc_device_type omap_rtc_am3352_type = {
+	.has_32kclk_en	= true,
+	.has_irqwakeen	= true,
+	.has_pmic_mode	= true,
+};
+
+static const struct omap_rtc_device_type omap_rtc_da830_type = {
+	.has_32kclk_en	= false,
+	.has_irqwakeen	= false,
+	.has_pmic_mode	= false,
+};
+
+static const struct udevice_id omap_rtc_ids[] = {
+	{.compatible = "ti,am3352-rtc", .data = (ulong)&omap_rtc_am3352_type},
+	{.compatible = "ti,da830-rtc", .data = (ulong)&omap_rtc_da830_type }
+};
+
+U_BOOT_DRIVER(omap_rtc) = {
+	.name = "omap_rtc",
+	.id = UCLASS_RTC,
+	.of_match = omap_rtc_ids,
+	.ops = &omap_rtc_ops,
+	.of_to_plat = omap_rtc_of_to_plat,
+	.probe = omap_rtc_probe,
+	.remove = omap_rtc_remove,
+	.priv_auto = sizeof(struct omap_rtc_priv),
+};