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1/*
2 * SH SCI SPI interface
3 *
4 * Copyright (c) 2008 Magnus Damm
5 *
6 * Based on S3C24XX GPIO based SPI driver, which is:
7 * Copyright (c) 2006 Ben Dooks
8 * Copyright (c) 2006 Simtec Electronics
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 */
15
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/delay.h>
19#include <linux/spinlock.h>
20#include <linux/workqueue.h>
21#include <linux/platform_device.h>
22
23#include <linux/spi/spi.h>
24#include <linux/spi/spi_bitbang.h>
25
26#include <asm/spi.h>
27#include <asm/io.h>
28
29struct sh_sci_spi {
30 struct spi_bitbang bitbang;
31
32 void __iomem *membase;
33 unsigned char val;
34 struct sh_spi_info *info;
35 struct platform_device *dev;
36};
37
38#define SCSPTR(sp) (sp->membase + 0x1c)
39#define PIN_SCK (1 << 2)
40#define PIN_TXD (1 << 0)
41#define PIN_RXD PIN_TXD
42#define PIN_INIT ((1 << 1) | (1 << 3) | PIN_SCK | PIN_TXD)
43
44static inline void setbits(struct sh_sci_spi *sp, int bits, int on)
45{
46 /*
47 * We are the only user of SCSPTR so no locking is required.
48 * Reading bit 2 and 0 in SCSPTR gives pin state as input.
49 * Writing the same bits sets the output value.
50 * This makes regular read-modify-write difficult so we
51 * use sp->val to keep track of the latest register value.
52 */
53
54 if (on)
55 sp->val |= bits;
56 else
57 sp->val &= ~bits;
58
59 iowrite8(sp->val, SCSPTR(sp));
60}
61
62static inline void setsck(struct spi_device *dev, int on)
63{
64 setbits(spi_master_get_devdata(dev->master), PIN_SCK, on);
65}
66
67static inline void setmosi(struct spi_device *dev, int on)
68{
69 setbits(spi_master_get_devdata(dev->master), PIN_TXD, on);
70}
71
72static inline u32 getmiso(struct spi_device *dev)
73{
74 struct sh_sci_spi *sp = spi_master_get_devdata(dev->master);
75
76 return (ioread8(SCSPTR(sp)) & PIN_RXD) ? 1 : 0;
77}
78
79#define spidelay(x) ndelay(x)
80
81#include "spi-bitbang-txrx.h"
82
83static u32 sh_sci_spi_txrx_mode0(struct spi_device *spi,
84 unsigned nsecs, u32 word, u8 bits)
85{
86 return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
87}
88
89static u32 sh_sci_spi_txrx_mode1(struct spi_device *spi,
90 unsigned nsecs, u32 word, u8 bits)
91{
92 return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
93}
94
95static u32 sh_sci_spi_txrx_mode2(struct spi_device *spi,
96 unsigned nsecs, u32 word, u8 bits)
97{
98 return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
99}
100
101static u32 sh_sci_spi_txrx_mode3(struct spi_device *spi,
102 unsigned nsecs, u32 word, u8 bits)
103{
104 return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
105}
106
107static void sh_sci_spi_chipselect(struct spi_device *dev, int value)
108{
109 struct sh_sci_spi *sp = spi_master_get_devdata(dev->master);
110
111 if (sp->info && sp->info->chip_select)
112 (sp->info->chip_select)(sp->info, dev->chip_select, value);
113}
114
115static int sh_sci_spi_probe(struct platform_device *dev)
116{
117 struct resource *r;
118 struct spi_master *master;
119 struct sh_sci_spi *sp;
120 int ret;
121
122 master = spi_alloc_master(&dev->dev, sizeof(struct sh_sci_spi));
123 if (master == NULL) {
124 dev_err(&dev->dev, "failed to allocate spi master\n");
125 ret = -ENOMEM;
126 goto err0;
127 }
128
129 sp = spi_master_get_devdata(master);
130
131 platform_set_drvdata(dev, sp);
132 sp->info = dev->dev.platform_data;
133
134 /* setup spi bitbang adaptor */
135 sp->bitbang.master = spi_master_get(master);
136 sp->bitbang.master->bus_num = sp->info->bus_num;
137 sp->bitbang.master->num_chipselect = sp->info->num_chipselect;
138 sp->bitbang.chipselect = sh_sci_spi_chipselect;
139
140 sp->bitbang.txrx_word[SPI_MODE_0] = sh_sci_spi_txrx_mode0;
141 sp->bitbang.txrx_word[SPI_MODE_1] = sh_sci_spi_txrx_mode1;
142 sp->bitbang.txrx_word[SPI_MODE_2] = sh_sci_spi_txrx_mode2;
143 sp->bitbang.txrx_word[SPI_MODE_3] = sh_sci_spi_txrx_mode3;
144
145 r = platform_get_resource(dev, IORESOURCE_MEM, 0);
146 if (r == NULL) {
147 ret = -ENOENT;
148 goto err1;
149 }
150 sp->membase = ioremap(r->start, resource_size(r));
151 if (!sp->membase) {
152 ret = -ENXIO;
153 goto err1;
154 }
155 sp->val = ioread8(SCSPTR(sp));
156 setbits(sp, PIN_INIT, 1);
157
158 ret = spi_bitbang_start(&sp->bitbang);
159 if (!ret)
160 return 0;
161
162 setbits(sp, PIN_INIT, 0);
163 iounmap(sp->membase);
164 err1:
165 spi_master_put(sp->bitbang.master);
166 err0:
167 return ret;
168}
169
170static int sh_sci_spi_remove(struct platform_device *dev)
171{
172 struct sh_sci_spi *sp = platform_get_drvdata(dev);
173
174 iounmap(sp->membase);
175 setbits(sp, PIN_INIT, 0);
176 spi_bitbang_stop(&sp->bitbang);
177 spi_master_put(sp->bitbang.master);
178 return 0;
179}
180
181static struct platform_driver sh_sci_spi_drv = {
182 .probe = sh_sci_spi_probe,
183 .remove = sh_sci_spi_remove,
184 .driver = {
185 .name = "spi_sh_sci",
186 .owner = THIS_MODULE,
187 },
188};
189
190static int __init sh_sci_spi_init(void)
191{
192 return platform_driver_register(&sh_sci_spi_drv);
193}
194module_init(sh_sci_spi_init);
195
196static void __exit sh_sci_spi_exit(void)
197{
198 platform_driver_unregister(&sh_sci_spi_drv);
199}
200module_exit(sh_sci_spi_exit);
201
202MODULE_DESCRIPTION("SH SCI SPI Driver");
203MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
204MODULE_LICENSE("GPL");
205MODULE_ALIAS("platform:spi_sh_sci");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * SH SCI SPI interface
4 *
5 * Copyright (c) 2008 Magnus Damm
6 *
7 * Based on S3C24XX GPIO based SPI driver, which is:
8 * Copyright (c) 2006 Ben Dooks
9 * Copyright (c) 2006 Simtec Electronics
10 */
11
12#include <linux/kernel.h>
13#include <linux/delay.h>
14#include <linux/spinlock.h>
15#include <linux/platform_device.h>
16
17#include <linux/spi/spi.h>
18#include <linux/spi/spi_bitbang.h>
19#include <linux/module.h>
20
21#include <asm/spi.h>
22#include <asm/io.h>
23
24struct sh_sci_spi {
25 struct spi_bitbang bitbang;
26
27 void __iomem *membase;
28 unsigned char val;
29 struct sh_spi_info *info;
30 struct platform_device *dev;
31};
32
33#define SCSPTR(sp) (sp->membase + 0x1c)
34#define PIN_SCK (1 << 2)
35#define PIN_TXD (1 << 0)
36#define PIN_RXD PIN_TXD
37#define PIN_INIT ((1 << 1) | (1 << 3) | PIN_SCK | PIN_TXD)
38
39static inline void setbits(struct sh_sci_spi *sp, int bits, int on)
40{
41 /*
42 * We are the only user of SCSPTR so no locking is required.
43 * Reading bit 2 and 0 in SCSPTR gives pin state as input.
44 * Writing the same bits sets the output value.
45 * This makes regular read-modify-write difficult so we
46 * use sp->val to keep track of the latest register value.
47 */
48
49 if (on)
50 sp->val |= bits;
51 else
52 sp->val &= ~bits;
53
54 iowrite8(sp->val, SCSPTR(sp));
55}
56
57static inline void setsck(struct spi_device *dev, int on)
58{
59 setbits(spi_master_get_devdata(dev->master), PIN_SCK, on);
60}
61
62static inline void setmosi(struct spi_device *dev, int on)
63{
64 setbits(spi_master_get_devdata(dev->master), PIN_TXD, on);
65}
66
67static inline u32 getmiso(struct spi_device *dev)
68{
69 struct sh_sci_spi *sp = spi_master_get_devdata(dev->master);
70
71 return (ioread8(SCSPTR(sp)) & PIN_RXD) ? 1 : 0;
72}
73
74#define spidelay(x) ndelay(x)
75
76#include "spi-bitbang-txrx.h"
77
78static u32 sh_sci_spi_txrx_mode0(struct spi_device *spi,
79 unsigned nsecs, u32 word, u8 bits,
80 unsigned flags)
81{
82 return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits);
83}
84
85static u32 sh_sci_spi_txrx_mode1(struct spi_device *spi,
86 unsigned nsecs, u32 word, u8 bits,
87 unsigned flags)
88{
89 return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits);
90}
91
92static u32 sh_sci_spi_txrx_mode2(struct spi_device *spi,
93 unsigned nsecs, u32 word, u8 bits,
94 unsigned flags)
95{
96 return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits);
97}
98
99static u32 sh_sci_spi_txrx_mode3(struct spi_device *spi,
100 unsigned nsecs, u32 word, u8 bits,
101 unsigned flags)
102{
103 return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits);
104}
105
106static void sh_sci_spi_chipselect(struct spi_device *dev, int value)
107{
108 struct sh_sci_spi *sp = spi_master_get_devdata(dev->master);
109
110 if (sp->info->chip_select)
111 (sp->info->chip_select)(sp->info, dev->chip_select, value);
112}
113
114static int sh_sci_spi_probe(struct platform_device *dev)
115{
116 struct resource *r;
117 struct spi_master *master;
118 struct sh_sci_spi *sp;
119 int ret;
120
121 master = spi_alloc_master(&dev->dev, sizeof(struct sh_sci_spi));
122 if (master == NULL) {
123 dev_err(&dev->dev, "failed to allocate spi master\n");
124 ret = -ENOMEM;
125 goto err0;
126 }
127
128 sp = spi_master_get_devdata(master);
129
130 platform_set_drvdata(dev, sp);
131 sp->info = dev_get_platdata(&dev->dev);
132 if (!sp->info) {
133 dev_err(&dev->dev, "platform data is missing\n");
134 ret = -ENOENT;
135 goto err1;
136 }
137
138 /* setup spi bitbang adaptor */
139 sp->bitbang.master = master;
140 sp->bitbang.master->bus_num = sp->info->bus_num;
141 sp->bitbang.master->num_chipselect = sp->info->num_chipselect;
142 sp->bitbang.chipselect = sh_sci_spi_chipselect;
143
144 sp->bitbang.txrx_word[SPI_MODE_0] = sh_sci_spi_txrx_mode0;
145 sp->bitbang.txrx_word[SPI_MODE_1] = sh_sci_spi_txrx_mode1;
146 sp->bitbang.txrx_word[SPI_MODE_2] = sh_sci_spi_txrx_mode2;
147 sp->bitbang.txrx_word[SPI_MODE_3] = sh_sci_spi_txrx_mode3;
148
149 r = platform_get_resource(dev, IORESOURCE_MEM, 0);
150 if (r == NULL) {
151 ret = -ENOENT;
152 goto err1;
153 }
154 sp->membase = ioremap(r->start, resource_size(r));
155 if (!sp->membase) {
156 ret = -ENXIO;
157 goto err1;
158 }
159 sp->val = ioread8(SCSPTR(sp));
160 setbits(sp, PIN_INIT, 1);
161
162 ret = spi_bitbang_start(&sp->bitbang);
163 if (!ret)
164 return 0;
165
166 setbits(sp, PIN_INIT, 0);
167 iounmap(sp->membase);
168 err1:
169 spi_master_put(sp->bitbang.master);
170 err0:
171 return ret;
172}
173
174static int sh_sci_spi_remove(struct platform_device *dev)
175{
176 struct sh_sci_spi *sp = platform_get_drvdata(dev);
177
178 spi_bitbang_stop(&sp->bitbang);
179 setbits(sp, PIN_INIT, 0);
180 iounmap(sp->membase);
181 spi_master_put(sp->bitbang.master);
182 return 0;
183}
184
185static struct platform_driver sh_sci_spi_drv = {
186 .probe = sh_sci_spi_probe,
187 .remove = sh_sci_spi_remove,
188 .driver = {
189 .name = "spi_sh_sci",
190 },
191};
192module_platform_driver(sh_sci_spi_drv);
193
194MODULE_DESCRIPTION("SH SCI SPI Driver");
195MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
196MODULE_LICENSE("GPL");
197MODULE_ALIAS("platform:spi_sh_sci");