1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
*/
#include <common.h>
#include <clock_legacy.h>
#include <dm.h>
#include <div64.h>
#include <errno.h>
#include <serial.h>
#include <asm/io.h>
#include <asm/addrspace.h>
#include <asm/types.h>
#include <dm/pinctrl.h>
#include <mach/ar71xx_regs.h>
#define AR933X_UART_DATA_REG 0x00
#define AR933X_UART_CS_REG 0x04
#define AR933X_UART_CLK_REG 0x08
#define AR933X_UART_DATA_TX_RX_MASK 0xff
#define AR933X_UART_DATA_RX_CSR BIT(8)
#define AR933X_UART_DATA_TX_CSR BIT(9)
#define AR933X_UART_CS_IF_MODE_S 2
#define AR933X_UART_CS_IF_MODE_M 0x3
#define AR933X_UART_CS_IF_MODE_DTE 1
#define AR933X_UART_CS_IF_MODE_DCE 2
#define AR933X_UART_CS_TX_RDY_ORIDE BIT(7)
#define AR933X_UART_CS_RX_RDY_ORIDE BIT(8)
#define AR933X_UART_CLK_STEP_M 0xffff
#define AR933X_UART_CLK_SCALE_M 0xfff
#define AR933X_UART_CLK_SCALE_S 16
#define AR933X_UART_CLK_STEP_S 0
struct ar933x_serial_priv {
void __iomem *regs;
};
/*
* Baudrate algorithm come from Linux/drivers/tty/serial/ar933x_uart.c
* baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
*/
static u32 ar933x_serial_get_baud(u32 clk, u32 scale, u32 step)
{
u64 t;
u32 div;
div = (2 << 16) * (scale + 1);
t = clk;
t *= step;
t += (div / 2);
do_div(t, div);
return t;
}
static void ar933x_serial_get_scale_step(u32 clk, u32 baud,
u32 *scale, u32 *step)
{
u32 tscale, baudrate;
long min_diff;
*scale = 0;
*step = 0;
min_diff = baud;
for (tscale = 0; tscale < AR933X_UART_CLK_SCALE_M; tscale++) {
u64 tstep;
int diff;
tstep = baud * (tscale + 1);
tstep *= (2 << 16);
do_div(tstep, clk);
if (tstep > AR933X_UART_CLK_STEP_M)
break;
baudrate = ar933x_serial_get_baud(clk, tscale, tstep);
diff = abs(baudrate - baud);
if (diff < min_diff) {
min_diff = diff;
*scale = tscale;
*step = tstep;
}
}
}
static int ar933x_serial_setbrg(struct udevice *dev, int baudrate)
{
struct ar933x_serial_priv *priv = dev_get_priv(dev);
u32 val, scale, step;
val = get_serial_clock();
ar933x_serial_get_scale_step(val, baudrate, &scale, &step);
val = (scale & AR933X_UART_CLK_SCALE_M)
<< AR933X_UART_CLK_SCALE_S;
val |= (step & AR933X_UART_CLK_STEP_M)
<< AR933X_UART_CLK_STEP_S;
writel(val, priv->regs + AR933X_UART_CLK_REG);
return 0;
}
static int ar933x_serial_putc(struct udevice *dev, const char c)
{
struct ar933x_serial_priv *priv = dev_get_priv(dev);
u32 data;
data = readl(priv->regs + AR933X_UART_DATA_REG);
if (!(data & AR933X_UART_DATA_TX_CSR))
return -EAGAIN;
data = (u32)c | AR933X_UART_DATA_TX_CSR;
writel(data, priv->regs + AR933X_UART_DATA_REG);
return 0;
}
static int ar933x_serial_getc(struct udevice *dev)
{
struct ar933x_serial_priv *priv = dev_get_priv(dev);
u32 data;
data = readl(priv->regs + AR933X_UART_DATA_REG);
if (!(data & AR933X_UART_DATA_RX_CSR))
return -EAGAIN;
writel(AR933X_UART_DATA_RX_CSR, priv->regs + AR933X_UART_DATA_REG);
return data & AR933X_UART_DATA_TX_RX_MASK;
}
static int ar933x_serial_pending(struct udevice *dev, bool input)
{
struct ar933x_serial_priv *priv = dev_get_priv(dev);
u32 data;
data = readl(priv->regs + AR933X_UART_DATA_REG);
if (input)
return (data & AR933X_UART_DATA_RX_CSR) ? 1 : 0;
else
return (data & AR933X_UART_DATA_TX_CSR) ? 0 : 1;
}
static int ar933x_serial_probe(struct udevice *dev)
{
struct ar933x_serial_priv *priv = dev_get_priv(dev);
fdt_addr_t addr;
u32 val;
addr = devfdt_get_addr(dev);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
priv->regs = map_physmem(addr, AR933X_UART_SIZE,
MAP_NOCACHE);
/*
* UART controller configuration:
* - no DMA
* - no interrupt
* - DCE mode
* - no flow control
* - set RX ready oride
* - set TX ready oride
*/
val = (AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S) |
AR933X_UART_CS_TX_RDY_ORIDE | AR933X_UART_CS_RX_RDY_ORIDE;
writel(val, priv->regs + AR933X_UART_CS_REG);
return 0;
}
static const struct dm_serial_ops ar933x_serial_ops = {
.putc = ar933x_serial_putc,
.pending = ar933x_serial_pending,
.getc = ar933x_serial_getc,
.setbrg = ar933x_serial_setbrg,
};
static const struct udevice_id ar933x_serial_ids[] = {
{ .compatible = "qca,ar9330-uart" },
{ }
};
U_BOOT_DRIVER(serial_ar933x) = {
.name = "serial_ar933x",
.id = UCLASS_SERIAL,
.of_match = ar933x_serial_ids,
.priv_auto_alloc_size = sizeof(struct ar933x_serial_priv),
.probe = ar933x_serial_probe,
.ops = &ar933x_serial_ops,
};
#ifdef CONFIG_DEBUG_UART_AR933X
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
void __iomem *regs = (void *)CONFIG_DEBUG_UART_BASE;
u32 val, scale, step;
/*
* UART controller configuration:
* - no DMA
* - no interrupt
* - DCE mode
* - no flow control
* - set RX ready oride
* - set TX ready oride
*/
val = (AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S) |
AR933X_UART_CS_TX_RDY_ORIDE | AR933X_UART_CS_RX_RDY_ORIDE;
writel(val, regs + AR933X_UART_CS_REG);
ar933x_serial_get_scale_step(CONFIG_DEBUG_UART_CLOCK,
CONFIG_BAUDRATE, &scale, &step);
val = (scale & AR933X_UART_CLK_SCALE_M)
<< AR933X_UART_CLK_SCALE_S;
val |= (step & AR933X_UART_CLK_STEP_M)
<< AR933X_UART_CLK_STEP_S;
writel(val, regs + AR933X_UART_CLK_REG);
}
static inline void _debug_uart_putc(int c)
{
void __iomem *regs = (void *)CONFIG_DEBUG_UART_BASE;
u32 data;
do {
data = readl(regs + AR933X_UART_DATA_REG);
} while (!(data & AR933X_UART_DATA_TX_CSR));
data = (u32)c | AR933X_UART_DATA_TX_CSR;
writel(data, regs + AR933X_UART_DATA_REG);
}
DEBUG_UART_FUNCS
#endif
|
