1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2011-2015 Vladimir Zapolskiy <vz@mleia.com>
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <serial.h>
9 #include <dm/platform_data/lpc32xx_hsuart.h>
10 
11 #include <asm/arch/uart.h>
12 #include <linux/compiler.h>
13 
14 struct lpc32xx_hsuart_priv {
15 	struct hsuart_regs *hsuart;
16 };
17 
18 static int lpc32xx_serial_setbrg(struct udevice *dev, int baudrate)
19 {
20 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
21 	struct hsuart_regs *hsuart = priv->hsuart;
22 	u32 div;
23 
24 	/* UART rate = PERIPH_CLK / ((HSU_RATE + 1) x 14) */
25 	div = (get_serial_clock() / 14 + baudrate / 2) / baudrate - 1;
26 	if (div > 255)
27 		div = 255;
28 
29 	writel(div, &hsuart->rate);
30 
31 	return 0;
32 }
33 
34 static int lpc32xx_serial_getc(struct udevice *dev)
35 {
36 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
37 	struct hsuart_regs *hsuart = priv->hsuart;
38 
39 	if (!(readl(&hsuart->level) & HSUART_LEVEL_RX))
40 		return -EAGAIN;
41 
42 	return readl(&hsuart->rx) & HSUART_RX_DATA;
43 }
44 
45 static int lpc32xx_serial_putc(struct udevice *dev, const char c)
46 {
47 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
48 	struct hsuart_regs *hsuart = priv->hsuart;
49 
50 	/* Wait for empty FIFO */
51 	if (readl(&hsuart->level) & HSUART_LEVEL_TX)
52 		return -EAGAIN;
53 
54 	writel(c, &hsuart->tx);
55 
56 	return 0;
57 }
58 
59 static int lpc32xx_serial_pending(struct udevice *dev, bool input)
60 {
61 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
62 	struct hsuart_regs *hsuart = priv->hsuart;
63 
64 	if (input) {
65 		if (readl(&hsuart->level) & HSUART_LEVEL_RX)
66 			return 1;
67 	} else {
68 		if (readl(&hsuart->level) & HSUART_LEVEL_TX)
69 			return 1;
70 	}
71 
72 	return 0;
73 }
74 
75 static int lpc32xx_serial_init(struct hsuart_regs *hsuart)
76 {
77 	/* Disable hardware RTS and CTS flow control, set up RX and TX FIFO */
78 	writel(HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) |
79 	       HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0,
80 	       &hsuart->ctrl);
81 
82 	return 0;
83 }
84 
85 static int lpc32xx_hsuart_probe(struct udevice *dev)
86 {
87 	struct lpc32xx_hsuart_platdata *platdata = dev_get_platdata(dev);
88 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
89 
90 	priv->hsuart = (struct hsuart_regs *)platdata->base;
91 
92 	lpc32xx_serial_init(priv->hsuart);
93 
94 	return 0;
95 }
96 
97 static const struct dm_serial_ops lpc32xx_hsuart_ops = {
98 	.setbrg	= lpc32xx_serial_setbrg,
99 	.getc	= lpc32xx_serial_getc,
100 	.putc	= lpc32xx_serial_putc,
101 	.pending = lpc32xx_serial_pending,
102 };
103 
104 U_BOOT_DRIVER(lpc32xx_hsuart) = {
105 	.name	= "lpc32xx_hsuart",
106 	.id	= UCLASS_SERIAL,
107 	.probe	= lpc32xx_hsuart_probe,
108 	.ops	= &lpc32xx_hsuart_ops,
109 	.priv_auto_alloc_size = sizeof(struct lpc32xx_hsuart_priv),
110 	.flags	= DM_FLAG_PRE_RELOC,
111 };
112