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
|
/*
* CLPS711X SPI bus driver
*
* Copyright (C) 2012-2014 Alexander Shiyan <shc_work@mail.ru>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/clps711x.h>
#include <linux/spi/spi.h>
#include <linux/platform_data/spi-clps711x.h>
#define DRIVER_NAME "spi-clps711x"
#define SYNCIO_FRMLEN(x) ((x) << 8)
#define SYNCIO_TXFRMEN (1 << 14)
struct spi_clps711x_data {
void __iomem *syncio;
struct regmap *syscon;
struct clk *spi_clk;
u8 *tx_buf;
u8 *rx_buf;
unsigned int bpw;
int len;
};
static int spi_clps711x_setup(struct spi_device *spi)
{
/* We are expect that SPI-device is not selected */
gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
return 0;
}
static int spi_clps711x_prepare_message(struct spi_master *master,
struct spi_message *msg)
{
struct spi_clps711x_data *hw = spi_master_get_devdata(master);
struct spi_device *spi = msg->spi;
/* Setup mode for transfer */
return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
(spi->mode & SPI_CPHA) ?
SYSCON3_ADCCKNSEN : 0);
}
static int spi_clps711x_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct spi_clps711x_data *hw = spi_master_get_devdata(master);
u8 data;
clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
hw->len = xfer->len;
hw->bpw = xfer->bits_per_word;
hw->tx_buf = (u8 *)xfer->tx_buf;
hw->rx_buf = (u8 *)xfer->rx_buf;
/* Initiate transfer */
data = hw->tx_buf ? *hw->tx_buf++ : 0;
writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);
return 1;
}
static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
{
struct spi_master *master = dev_id;
struct spi_clps711x_data *hw = spi_master_get_devdata(master);
u8 data;
/* Handle RX */
data = readb(hw->syncio);
if (hw->rx_buf)
*hw->rx_buf++ = data;
/* Handle TX */
if (--hw->len > 0) {
data = hw->tx_buf ? *hw->tx_buf++ : 0;
writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
hw->syncio);
} else
spi_finalize_current_transfer(master);
return IRQ_HANDLED;
}
static int spi_clps711x_probe(struct platform_device *pdev)
{
struct spi_clps711x_data *hw;
struct spi_clps711x_pdata *pdata = dev_get_platdata(&pdev->dev);
struct spi_master *master;
struct resource *res;
int i, irq, ret;
if (!pdata) {
dev_err(&pdev->dev, "No platform data supplied\n");
return -EINVAL;
}
if (pdata->num_chipselect < 1) {
dev_err(&pdev->dev, "At least one CS must be defined\n");
return -EINVAL;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
master = spi_alloc_master(&pdev->dev, sizeof(*hw));
if (!master)
return -ENOMEM;
master->cs_gpios = devm_kzalloc(&pdev->dev, sizeof(int) *
pdata->num_chipselect, GFP_KERNEL);
if (!master->cs_gpios) {
ret = -ENOMEM;
goto err_out;
}
master->bus_num = pdev->id;
master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
master->num_chipselect = pdata->num_chipselect;
master->setup = spi_clps711x_setup;
master->prepare_message = spi_clps711x_prepare_message;
master->transfer_one = spi_clps711x_transfer_one;
hw = spi_master_get_devdata(master);
for (i = 0; i < master->num_chipselect; i++) {
master->cs_gpios[i] = pdata->chipselect[i];
ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
DRIVER_NAME);
if (ret) {
dev_err(&pdev->dev, "Can't get CS GPIO %i\n", i);
goto err_out;
}
}
hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(hw->spi_clk)) {
ret = PTR_ERR(hw->spi_clk);
goto err_out;
}
hw->syscon = syscon_regmap_lookup_by_pdevname("syscon.3");
if (IS_ERR(hw->syscon)) {
ret = PTR_ERR(hw->syscon);
goto err_out;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
hw->syncio = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hw->syncio)) {
ret = PTR_ERR(hw->syncio);
goto err_out;
}
/* Disable extended mode due hardware problems */
regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
/* Clear possible pending interrupt */
readl(hw->syncio);
ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
dev_name(&pdev->dev), master);
if (ret)
goto err_out;
ret = devm_spi_register_master(&pdev->dev, master);
if (!ret) {
dev_info(&pdev->dev,
"SPI bus driver initialized. Master clock %u Hz\n",
master->max_speed_hz);
return 0;
}
dev_err(&pdev->dev, "Failed to register master\n");
err_out:
spi_master_put(master);
return ret;
}
static struct platform_driver clps711x_spi_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
},
.probe = spi_clps711x_probe,
};
module_platform_driver(clps711x_spi_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("CLPS711X SPI bus driver");
MODULE_ALIAS("platform:" DRIVER_NAME);
|
