1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2016 Stefan Roese <sr@denx.de>
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <serial.h>
9 #include <asm/io.h>
10
11 struct mvebu_platdata {
12 void __iomem *base;
13 };
14
15 /*
16 * Register offset
17 */
18 #define UART_RX_REG 0x00
19 #define UART_TX_REG 0x04
20 #define UART_CTRL_REG 0x08
21 #define UART_STATUS_REG 0x0c
22 #define UART_BAUD_REG 0x10
23 #define UART_POSSR_REG 0x14
24
25 #define UART_STATUS_RX_RDY 0x10
26 #define UART_STATUS_TXFIFO_FULL 0x800
27
28 #define UART_CTRL_RXFIFO_RESET 0x4000
29 #define UART_CTRL_TXFIFO_RESET 0x8000
30
31 #define CONFIG_UART_BASE_CLOCK 25804800
32
mvebu_serial_putc(struct udevice * dev,const char ch)33 static int mvebu_serial_putc(struct udevice *dev, const char ch)
34 {
35 struct mvebu_platdata *plat = dev_get_platdata(dev);
36 void __iomem *base = plat->base;
37
38 while (readl(base + UART_STATUS_REG) & UART_STATUS_TXFIFO_FULL)
39 ;
40
41 writel(ch, base + UART_TX_REG);
42
43 return 0;
44 }
45
mvebu_serial_getc(struct udevice * dev)46 static int mvebu_serial_getc(struct udevice *dev)
47 {
48 struct mvebu_platdata *plat = dev_get_platdata(dev);
49 void __iomem *base = plat->base;
50
51 while (!(readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY))
52 ;
53
54 return readl(base + UART_RX_REG) & 0xff;
55 }
56
mvebu_serial_pending(struct udevice * dev,bool input)57 static int mvebu_serial_pending(struct udevice *dev, bool input)
58 {
59 struct mvebu_platdata *plat = dev_get_platdata(dev);
60 void __iomem *base = plat->base;
61
62 if (readl(base + UART_STATUS_REG) & UART_STATUS_RX_RDY)
63 return 1;
64
65 return 0;
66 }
67
mvebu_serial_setbrg(struct udevice * dev,int baudrate)68 static int mvebu_serial_setbrg(struct udevice *dev, int baudrate)
69 {
70 struct mvebu_platdata *plat = dev_get_platdata(dev);
71 void __iomem *base = plat->base;
72
73 /*
74 * Calculate divider
75 * baudrate = clock / 16 / divider
76 */
77 writel(CONFIG_UART_BASE_CLOCK / baudrate / 16, base + UART_BAUD_REG);
78
79 /*
80 * Set Programmable Oversampling Stack to 0,
81 * UART defaults to 16x scheme
82 */
83 writel(0, base + UART_POSSR_REG);
84
85 return 0;
86 }
87
mvebu_serial_probe(struct udevice * dev)88 static int mvebu_serial_probe(struct udevice *dev)
89 {
90 struct mvebu_platdata *plat = dev_get_platdata(dev);
91 void __iomem *base = plat->base;
92
93 /* reset FIFOs */
94 writel(UART_CTRL_RXFIFO_RESET | UART_CTRL_TXFIFO_RESET,
95 base + UART_CTRL_REG);
96
97 /* No Parity, 1 Stop */
98 writel(0, base + UART_CTRL_REG);
99
100 return 0;
101 }
102
mvebu_serial_ofdata_to_platdata(struct udevice * dev)103 static int mvebu_serial_ofdata_to_platdata(struct udevice *dev)
104 {
105 struct mvebu_platdata *plat = dev_get_platdata(dev);
106
107 plat->base = devfdt_get_addr_ptr(dev);
108
109 return 0;
110 }
111
112 static const struct dm_serial_ops mvebu_serial_ops = {
113 .putc = mvebu_serial_putc,
114 .pending = mvebu_serial_pending,
115 .getc = mvebu_serial_getc,
116 .setbrg = mvebu_serial_setbrg,
117 };
118
119 static const struct udevice_id mvebu_serial_ids[] = {
120 { .compatible = "marvell,armada-3700-uart" },
121 { }
122 };
123
124 U_BOOT_DRIVER(serial_mvebu) = {
125 .name = "serial_mvebu",
126 .id = UCLASS_SERIAL,
127 .of_match = mvebu_serial_ids,
128 .ofdata_to_platdata = mvebu_serial_ofdata_to_platdata,
129 .platdata_auto_alloc_size = sizeof(struct mvebu_platdata),
130 .probe = mvebu_serial_probe,
131 .ops = &mvebu_serial_ops,
132 .flags = DM_FLAG_PRE_RELOC,
133 };
134
135 #ifdef CONFIG_DEBUG_MVEBU_A3700_UART
136
137 #include <debug_uart.h>
138
_debug_uart_init(void)139 static inline void _debug_uart_init(void)
140 {
141 void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
142
143 /* reset FIFOs */
144 writel(UART_CTRL_RXFIFO_RESET | UART_CTRL_TXFIFO_RESET,
145 base + UART_CTRL_REG);
146
147 /* No Parity, 1 Stop */
148 writel(0, base + UART_CTRL_REG);
149
150 /*
151 * Calculate divider
152 * baudrate = clock / 16 / divider
153 */
154 writel(CONFIG_UART_BASE_CLOCK / 115200 / 16, base + UART_BAUD_REG);
155
156 /*
157 * Set Programmable Oversampling Stack to 0,
158 * UART defaults to 16x scheme
159 */
160 writel(0, base + UART_POSSR_REG);
161 }
162
_debug_uart_putc(int ch)163 static inline void _debug_uart_putc(int ch)
164 {
165 void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
166
167 while (readl(base + UART_STATUS_REG) & UART_STATUS_TXFIFO_FULL)
168 ;
169
170 writel(ch, base + UART_TX_REG);
171 }
172
173 DEBUG_UART_FUNCS
174 #endif
175