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
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
|
// SPDX-License-Identifier: GPL-2.0+
/*
* Renesas RCar IIC driver
*
* Copyright (C) 2017 Marek Vasut <marek.vasut@gmail.com>
*
* Based on
* Copyright (C) 2011, 2013 Renesas Solutions Corp.
* Copyright (C) 2011, 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <i2c.h>
#include <asm/io.h>
struct rcar_iic_priv {
void __iomem *base;
struct clk clk;
u8 iccl;
u8 icch;
};
#define RCAR_IIC_ICDR 0x00
#define RCAR_IIC_ICCR 0x04
#define RCAR_IIC_ICSR 0x08
#define RCAR_IIC_ICIC 0x0c
#define RCAR_IIC_ICCL 0x10
#define RCAR_IIC_ICCH 0x14
/* ICCR */
#define RCAR_IIC_ICCR_ICE BIT(7)
#define RCAR_IIC_ICCR_RACK BIT(6)
#define RCAR_IIC_ICCR_RTS BIT(4)
#define RCAR_IIC_ICCR_BUSY BIT(2)
#define RCAR_IIC_ICCR_SCP BIT(0)
/* ICSR / ICIC */
#define RCAR_IC_BUSY BIT(4)
#define RCAR_IC_TACK BIT(2)
#define RCAR_IC_DTE BIT(0)
#define IRQ_WAIT 1000
static void sh_irq_dte(struct udevice *dev)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
int i;
for (i = 0; i < IRQ_WAIT; i++) {
if (RCAR_IC_DTE & readb(priv->base + RCAR_IIC_ICSR))
break;
udelay(10);
}
}
static int sh_irq_dte_with_tack(struct udevice *dev)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
u8 icsr;
int i;
for (i = 0; i < IRQ_WAIT; i++) {
icsr = readb(priv->base + RCAR_IIC_ICSR);
if (RCAR_IC_DTE & icsr)
break;
if (RCAR_IC_TACK & icsr)
return -ETIMEDOUT;
udelay(10);
}
return 0;
}
static void sh_irq_busy(struct udevice *dev)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
int i;
for (i = 0; i < IRQ_WAIT; i++) {
if (!(RCAR_IC_BUSY & readb(priv->base + RCAR_IIC_ICSR)))
break;
udelay(10);
}
}
static int rcar_iic_set_addr(struct udevice *dev, u8 chip, u8 read)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
clrbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
setbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
writeb(priv->iccl, priv->base + RCAR_IIC_ICCL);
writeb(priv->icch, priv->base + RCAR_IIC_ICCH);
writeb(RCAR_IC_TACK, priv->base + RCAR_IIC_ICIC);
writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RTS | RCAR_IIC_ICCR_BUSY,
priv->base + RCAR_IIC_ICCR);
sh_irq_dte(dev);
clrbits_8(priv->base + RCAR_IIC_ICSR, RCAR_IC_TACK);
writeb(chip << 1 | read, priv->base + RCAR_IIC_ICDR);
return sh_irq_dte_with_tack(dev);
}
static void rcar_iic_finish(struct udevice *dev)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
writeb(0, priv->base + RCAR_IIC_ICSR);
clrbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
}
static int rcar_iic_read_common(struct udevice *dev, struct i2c_msg *msg)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
int i, ret = -EREMOTEIO;
if (rcar_iic_set_addr(dev, msg->addr, 1) != 0)
goto err;
udelay(10);
writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_SCP,
priv->base + RCAR_IIC_ICCR);
for (i = 0; i < msg->len; i++) {
if (sh_irq_dte_with_tack(dev) != 0)
goto err;
msg->buf[i] = readb(priv->base + RCAR_IIC_ICDR) & 0xff;
if (msg->len - 1 == i) {
writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RACK,
priv->base + RCAR_IIC_ICCR);
}
}
sh_irq_busy(dev);
ret = 0;
err:
rcar_iic_finish(dev);
return ret;
}
static int rcar_iic_write_common(struct udevice *dev, struct i2c_msg *msg)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
int i, ret = -EREMOTEIO;
if (rcar_iic_set_addr(dev, msg->addr, 0) != 0)
goto err;
udelay(10);
for (i = 0; i < msg->len; i++) {
writeb(msg->buf[i], priv->base + RCAR_IIC_ICDR);
if (sh_irq_dte_with_tack(dev) != 0)
goto err;
}
if (msg->flags & I2C_M_STOP) {
writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RTS,
priv->base + RCAR_IIC_ICCR);
if (sh_irq_dte_with_tack(dev) != 0)
goto err;
}
sh_irq_busy(dev);
ret = 0;
err:
rcar_iic_finish(dev);
return ret;
}
static int rcar_iic_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
{
int ret;
for (; nmsgs > 0; nmsgs--, msg++) {
if (msg->flags & I2C_M_RD)
ret = rcar_iic_read_common(dev, msg);
else
ret = rcar_iic_write_common(dev, msg);
if (ret)
return -EREMOTEIO;
}
return ret;
}
static int rcar_iic_set_speed(struct udevice *dev, uint speed)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
const unsigned int ratio_high = 4;
const unsigned int ratio_low = 5;
int clkrate, denom;
clkrate = clk_get_rate(&priv->clk);
if (clkrate < 0)
return clkrate;
/*
* Calculate the value for ICCL and ICCH. From the data sheet:
* iccl = (p-clock / transfer-rate) * (L / (L + H))
* icch = (p clock / transfer rate) * (H / (L + H))
* where L and H are the SCL low and high ratio.
*/
denom = speed * (ratio_high + ratio_low);
priv->iccl = DIV_ROUND_CLOSEST(clkrate * ratio_low, denom);
priv->icch = DIV_ROUND_CLOSEST(clkrate * ratio_high, denom);
return 0;
}
static int rcar_iic_probe_chip(struct udevice *dev, uint addr, uint flags)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
int ret;
rcar_iic_set_addr(dev, addr, 1);
writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_SCP,
priv->base + RCAR_IIC_ICCR);
ret = sh_irq_dte_with_tack(dev);
rcar_iic_finish(dev);
return ret;
}
static int rcar_iic_probe(struct udevice *dev)
{
struct rcar_iic_priv *priv = dev_get_priv(dev);
int ret;
priv->base = dev_read_addr_ptr(dev);
ret = clk_get_by_index(dev, 0, &priv->clk);
if (ret)
return ret;
ret = clk_enable(&priv->clk);
if (ret)
return ret;
rcar_iic_finish(dev);
return rcar_iic_set_speed(dev, 100000);
}
static const struct dm_i2c_ops rcar_iic_ops = {
.xfer = rcar_iic_xfer,
.probe_chip = rcar_iic_probe_chip,
.set_bus_speed = rcar_iic_set_speed,
};
static const struct udevice_id rcar_iic_ids[] = {
{ .compatible = "renesas,rmobile-iic" },
{ }
};
U_BOOT_DRIVER(iic_rcar) = {
.name = "iic_rcar",
.id = UCLASS_I2C,
.of_match = rcar_iic_ids,
.probe = rcar_iic_probe,
.priv_auto_alloc_size = sizeof(struct rcar_iic_priv),
.ops = &rcar_iic_ops,
};
|
