serial: lpuart: support uclass clk api

Modify most APIs to use udevice as the first parameter, then
it will be easy to get the clk reference by using udevice pointer.
Use uclass api to get lpuart clk when CONFIG_CLK is enabled.
Signed-off-by: NPeng Fan <peng.fan@nxp.com>
Signed-off-by: NAnatolij Gustschin <agust@denx.de>
Cc: Stefano Babic <sbabic@denx.de>

drivers/serial/serial_lpuart.c

@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <clk.h>
 #include <dm.h>
 #include <fsl_lpuart.h>
 #include <watchdog.h>
@@ -104,6 +105,32 @@ u32 __weak get_lpuart_clk(void)
 	return CONFIG_SYS_CLK_FREQ;
 }
 
+#if IS_ENABLED(CONFIG_CLK)
+static int get_lpuart_clk_rate(struct udevice *dev, u32 *clk)
+{
+	struct clk per_clk;
+	ulong rate;
+	int ret;
+
+	ret = clk_get_by_name(dev, "per", &per_clk);
+	if (ret) {
+		dev_err(dev, "Failed to get per clk: %d\n", ret);
+		return ret;
+	}
+
+	rate = clk_get_rate(&per_clk);
+	if ((long)rate <= 0) {
+		dev_err(dev, "Failed to get per clk rate: %ld\n", (long)rate);
+		return ret;
+	}
+	*clk = rate;
+	return 0;
+}
+#else
+static inline int get_lpuart_clk_rate(struct udevice *dev, u32 *clk)
+{ return -ENOSYS; }
+#endif
+
 static bool is_lpuart32(struct udevice *dev)
 {
 	struct lpuart_serial_platdata *plat = dev->platdata;
@@ -111,12 +138,22 @@ static bool is_lpuart32(struct udevice *dev)
 	return plat->flags & LPUART_FLAG_REGMAP_32BIT_REG;
 }
 
-static void _lpuart_serial_setbrg(struct lpuart_serial_platdata *plat,
+static void _lpuart_serial_setbrg(struct udevice *dev,
 				  int baudrate)
 {
+	struct lpuart_serial_platdata *plat = dev_get_platdata(dev);
 	struct lpuart_fsl *base = plat->reg;
-	u32 clk = get_lpuart_clk();
+	u32 clk;
 	u16 sbr;
+	int ret;
+
+	if (IS_ENABLED(CONFIG_CLK)) {
+		ret = get_lpuart_clk_rate(dev, &clk);
+		if (ret)
+			return;
+	} else {
+		clk = get_lpuart_clk();
+	}
 
 	sbr = (u16)(clk / (16 * baudrate));
 
@@ -162,8 +199,9 @@ static int _lpuart_serial_tstc(struct lpuart_serial_platdata *plat)
  * Initialise the serial port with the given baudrate. The settings
  * are always 8 data bits, no parity, 1 stop bit, no start bits.
  */
-static int _lpuart_serial_init(struct lpuart_serial_platdata *plat)
+static int _lpuart_serial_init(struct udevice *dev)
 {
+	struct lpuart_serial_platdata *plat = dev_get_platdata(dev);
 	struct lpuart_fsl *base = (struct lpuart_fsl *)plat->reg;
 	u8 ctrl;
 
@@ -182,19 +220,29 @@ static int _lpuart_serial_init(struct lpuart_serial_platdata *plat)
 	__raw_writeb(CFIFO_TXFLUSH | CFIFO_RXFLUSH, &base->ucfifo);
 
 	/* provide data bits, parity, stop bit, etc */
-	_lpuart_serial_setbrg(plat, gd->baudrate);
+	_lpuart_serial_setbrg(dev, gd->baudrate);
 
 	__raw_writeb(UC2_RE | UC2_TE, &base->uc2);
 
 	return 0;
 }
 
-static void _lpuart32_serial_setbrg_7ulp(struct lpuart_serial_platdata *plat,
+static void _lpuart32_serial_setbrg_7ulp(struct udevice *dev,
 					 int baudrate)
 {
+	struct lpuart_serial_platdata *plat = dev_get_platdata(dev);
 	struct lpuart_fsl_reg32 *base = plat->reg;
 	u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp;
-	u32 clk = get_lpuart_clk();
+	u32 clk;
+	int ret;
+
+	if (IS_ENABLED(CONFIG_CLK)) {
+		ret = get_lpuart_clk_rate(dev, &clk);
+		if (ret)
+			return;
+	} else {
+		clk = get_lpuart_clk();
+	}
 
 	baud_diff = baudrate;
 	osr = 0;
@@ -248,12 +296,22 @@ static void _lpuart32_serial_setbrg_7ulp(struct lpuart_serial_platdata *plat,
 	out_le32(&base->baud, tmp);
 }
 
-static void _lpuart32_serial_setbrg(struct lpuart_serial_platdata *plat,
+static void _lpuart32_serial_setbrg(struct udevice *dev,
 				    int baudrate)
 {
+	struct lpuart_serial_platdata *plat = dev_get_platdata(dev);
 	struct lpuart_fsl_reg32 *base = plat->reg;
-	u32 clk = get_lpuart_clk();
+	u32 clk;
 	u32 sbr;
+	int ret;
+
+	if (IS_ENABLED(CONFIG_CLK)) {
+		ret = get_lpuart_clk_rate(dev, &clk);
+		if (ret)
+			return;
+	} else {
+		clk = get_lpuart_clk();
+	}
 
 	sbr = (clk / (16 * baudrate));
 
@@ -321,8 +379,9 @@ static int _lpuart32_serial_tstc(struct lpuart_serial_platdata *plat)
  * Initialise the serial port with the given baudrate. The settings
  * are always 8 data bits, no parity, 1 stop bit, no start bits.
  */
-static int _lpuart32_serial_init(struct lpuart_serial_platdata *plat)
+static int _lpuart32_serial_init(struct udevice *dev)
 {
+	struct lpuart_serial_platdata *plat = dev_get_platdata(dev);
 	struct lpuart_fsl_reg32 *base = (struct lpuart_fsl_reg32 *)plat->reg;
 	u32 val, tx_fifo_size;
 
@@ -350,10 +409,10 @@ static int _lpuart32_serial_init(struct lpuart_serial_platdata *plat)
 	lpuart_write32(plat->flags, &base->match, 0);
 
 	if (plat->devtype == DEV_MX7ULP || plat->devtype == DEV_IMX8) {
-		_lpuart32_serial_setbrg_7ulp(plat, gd->baudrate);
+		_lpuart32_serial_setbrg_7ulp(dev, gd->baudrate);
 	} else {
 		/* provide data bits, parity, stop bit, etc */
-		_lpuart32_serial_setbrg(plat, gd->baudrate);
+		_lpuart32_serial_setbrg(dev, gd->baudrate);
 	}
 
 	lpuart_write32(plat->flags, &base->ctrl, CTRL_RE | CTRL_TE);
@@ -363,15 +422,15 @@ static int _lpuart32_serial_init(struct lpuart_serial_platdata *plat)
 
 static int lpuart_serial_setbrg(struct udevice *dev, int baudrate)
 {
-	struct lpuart_serial_platdata *plat = dev->platdata;
+	struct lpuart_serial_platdata *plat = dev_get_platdata(dev);
 
 	if (is_lpuart32(dev)) {
 		if (plat->devtype == DEV_MX7ULP || plat->devtype == DEV_IMX8)
-			_lpuart32_serial_setbrg_7ulp(plat, baudrate);
+			_lpuart32_serial_setbrg_7ulp(dev, baudrate);
 		else
-			_lpuart32_serial_setbrg(plat, baudrate);
+			_lpuart32_serial_setbrg(dev, baudrate);
 	} else {
-		_lpuart_serial_setbrg(plat, baudrate);
+		_lpuart_serial_setbrg(dev, baudrate);
 	}
 
 	return 0;
@@ -423,12 +482,10 @@ static int lpuart_serial_pending(struct udevice *dev, bool input)
 
 static int lpuart_serial_probe(struct udevice *dev)
 {
-	struct lpuart_serial_platdata *plat = dev->platdata;
-
 	if (is_lpuart32(dev))
-		return _lpuart32_serial_init(plat);
+		return _lpuart32_serial_init(dev);
 	else
-		return _lpuart_serial_init(plat);
+		return _lpuart_serial_init(dev);
 }
 
 static int lpuart_serial_ofdata_to_platdata(struct udevice *dev)