1 /*
2  * Copyright (C) 2011-2015 Vladimir Zapolskiy <vz@mleia.com>
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <serial.h>
10 #include <dm/platform_data/lpc32xx_hsuart.h>
11 
12 #include <asm/arch/uart.h>
13 #include <linux/compiler.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 struct lpc32xx_hsuart_priv {
18 	struct hsuart_regs *hsuart;
19 };
20 
21 static int lpc32xx_serial_setbrg(struct udevice *dev, int baudrate)
22 {
23 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
24 	struct hsuart_regs *hsuart = priv->hsuart;
25 	u32 div;
26 
27 	/* UART rate = PERIPH_CLK / ((HSU_RATE + 1) x 14) */
28 	div = (get_serial_clock() / 14 + baudrate / 2) / baudrate - 1;
29 	if (div > 255)
30 		div = 255;
31 
32 	writel(div, &hsuart->rate);
33 
34 	return 0;
35 }
36 
37 static int lpc32xx_serial_getc(struct udevice *dev)
38 {
39 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
40 	struct hsuart_regs *hsuart = priv->hsuart;
41 
42 	if (!(readl(&hsuart->level) & HSUART_LEVEL_RX))
43 		return -EAGAIN;
44 
45 	return readl(&hsuart->rx) & HSUART_RX_DATA;
46 }
47 
48 static int lpc32xx_serial_putc(struct udevice *dev, const char c)
49 {
50 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
51 	struct hsuart_regs *hsuart = priv->hsuart;
52 
53 	/* Wait for empty FIFO */
54 	if (readl(&hsuart->level) & HSUART_LEVEL_TX)
55 		return -EAGAIN;
56 
57 	writel(c, &hsuart->tx);
58 
59 	return 0;
60 }
61 
62 static int lpc32xx_serial_pending(struct udevice *dev, bool input)
63 {
64 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
65 	struct hsuart_regs *hsuart = priv->hsuart;
66 
67 	if (input) {
68 		if (readl(&hsuart->level) & HSUART_LEVEL_RX)
69 			return 1;
70 	} else {
71 		if (readl(&hsuart->level) & HSUART_LEVEL_TX)
72 			return 1;
73 	}
74 
75 	return 0;
76 }
77 
78 static int lpc32xx_serial_init(struct hsuart_regs *hsuart)
79 {
80 	/* Disable hardware RTS and CTS flow control, set up RX and TX FIFO */
81 	writel(HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) |
82 	       HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0,
83 	       &hsuart->ctrl);
84 
85 	return 0;
86 }
87 
88 static int lpc32xx_hsuart_probe(struct udevice *dev)
89 {
90 	struct lpc32xx_hsuart_platdata *platdata = dev_get_platdata(dev);
91 	struct lpc32xx_hsuart_priv *priv = dev_get_priv(dev);
92 
93 	priv->hsuart = (struct hsuart_regs *)platdata->base;
94 
95 	lpc32xx_serial_init(priv->hsuart);
96 
97 	return 0;
98 }
99 
100 static const struct dm_serial_ops lpc32xx_hsuart_ops = {
101 	.setbrg	= lpc32xx_serial_setbrg,
102 	.getc	= lpc32xx_serial_getc,
103 	.putc	= lpc32xx_serial_putc,
104 	.pending = lpc32xx_serial_pending,
105 };
106 
107 U_BOOT_DRIVER(lpc32xx_hsuart) = {
108 	.name	= "lpc32xx_hsuart",
109 	.id	= UCLASS_SERIAL,
110 	.probe	= lpc32xx_hsuart_probe,
111 	.ops	= &lpc32xx_hsuart_ops,
112 	.priv_auto_alloc_size = sizeof(struct lpc32xx_hsuart_priv),
113 	.flags	= DM_FLAG_PRE_RELOC,
114 };
115