aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/patches-2.6.34/921-gpio_spi_driver.patch
blob: 65f17b49eb90785ea538425971ffa7d01ce211a3 (plain)
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
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
THIS CODE IS DEPRECATED.

Please use the new mainline SPI-GPIO driver, as of 2.6.29.

--mb



--- /dev/null
+++ b/include/linux/spi/spi_gpio_old.h
@@ -0,0 +1,73 @@
+/*
+ * spi_gpio interface to platform code
+ *
+ * Copyright (c) 2008 Piotr Skamruk
+ * Copyright (c) 2008 Michael Buesch
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef _LINUX_SPI_SPI_GPIO
+#define _LINUX_SPI_SPI_GPIO
+
+#include <linux/types.h>
+#include <linux/spi/spi.h>
+
+
+/**
+ * struct spi_gpio_platform_data - Data definitions for a SPI-GPIO device.
+ *
+ * This structure holds information about a GPIO-based SPI device.
+ *
+ * @pin_clk: The GPIO pin number of the CLOCK pin.
+ *
+ * @pin_miso: The GPIO pin number of the MISO pin.
+ *
+ * @pin_mosi: The GPIO pin number of the MOSI pin.
+ *
+ * @pin_cs: The GPIO pin number of the CHIPSELECT pin.
+ *
+ * @cs_activelow: If true, the chip is selected when the CS line is low.
+ *
+ * @no_spi_delay: If true, no delay is done in the lowlevel bitbanging.
+ *                Note that doing no delay is not standards compliant,
+ *                but it might be needed to speed up transfers on some
+ *                slow embedded machines.
+ *
+ * @boardinfo_setup: This callback is called after the
+ *                   SPI master device was registered, but before the
+ *                   device is registered.
+ * @boardinfo_setup_data: Data argument passed to boardinfo_setup().
+ */
+struct spi_gpio_platform_data {
+	unsigned int pin_clk;
+	unsigned int pin_miso;
+	unsigned int pin_mosi;
+	unsigned int pin_cs;
+	bool cs_activelow;
+	bool no_spi_delay;
+	int (*boardinfo_setup)(struct spi_board_info *bi,
+			       struct spi_master *master,
+			       void *data);
+	void *boardinfo_setup_data;
+};
+
+/**
+ * SPI_GPIO_PLATDEV_NAME - The platform device name string.
+ *
+ * The name string that has to be used for platform_device_alloc
+ * when allocating a spi-gpio device.
+ */
+#define SPI_GPIO_PLATDEV_NAME	"spi-gpio"
+
+/**
+ * spi_gpio_next_id - Get another platform device ID number.
+ *
+ * This returns the next platform device ID number that has to be used
+ * for platform_device_alloc. The ID is opaque and should not be used for
+ * anything else.
+ */
+int spi_gpio_next_id(void);
+
+#endif /* _LINUX_SPI_SPI_GPIO */
--- /dev/null
+++ b/drivers/spi/spi_gpio_old.c
@@ -0,0 +1,251 @@
+/*
+ * Bitbanging SPI bus driver using GPIO API
+ *
+ * Copyright (c) 2008 Piotr Skamruk
+ * Copyright (c) 2008 Michael Buesch
+ *
+ * based on spi_s3c2410_gpio.c
+ *   Copyright (c) 2006 Ben Dooks
+ *   Copyright (c) 2006 Simtec Electronics
+ * and on i2c-gpio.c
+ *   Copyright (C) 2007 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/spi_gpio_old.h>
+#include <linux/gpio.h>
+#include <asm/atomic.h>
+
+
+struct spi_gpio {
+	struct spi_bitbang bitbang;
+	struct spi_gpio_platform_data *info;
+	struct platform_device *pdev;
+	struct spi_board_info bi;
+};
+
+
+static inline struct spi_gpio *spidev_to_sg(struct spi_device *dev)
+{
+	return dev->controller_data;
+}
+
+static inline void setsck(struct spi_device *dev, int val)
+{
+	struct spi_gpio *sp = spidev_to_sg(dev);
+	gpio_set_value(sp->info->pin_clk, val ? 1 : 0);
+}
+
+static inline void setmosi(struct spi_device *dev, int val)
+{
+	struct spi_gpio *sp = spidev_to_sg(dev);
+	gpio_set_value(sp->info->pin_mosi, val ? 1 : 0);
+}
+
+static inline u32 getmiso(struct spi_device *dev)
+{
+	struct spi_gpio *sp = spidev_to_sg(dev);
+	return gpio_get_value(sp->info->pin_miso) ? 1 : 0;
+}
+
+static inline void do_spidelay(struct spi_device *dev, unsigned nsecs)
+{
+	struct spi_gpio *sp = spidev_to_sg(dev);
+
+	if (!sp->info->no_spi_delay)
+		ndelay(nsecs);
+}
+
+#define spidelay(nsecs) do {					\
+	/* Steal the spi_device pointer from our caller.	\
+	 * The bitbang-API should probably get fixed here... */	\
+	do_spidelay(spi, nsecs);				\
+  } while (0)
+
+#define EXPAND_BITBANG_TXRX
+#include <linux/spi/spi_bitbang.h>
+
+static u32 spi_gpio_txrx_mode0(struct spi_device *spi,
+			       unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
+}
+
+static u32 spi_gpio_txrx_mode1(struct spi_device *spi,
+			       unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
+}
+
+static u32 spi_gpio_txrx_mode2(struct spi_device *spi,
+			       unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
+}
+
+static u32 spi_gpio_txrx_mode3(struct spi_device *spi,
+			       unsigned nsecs, u32 word, u8 bits)
+{
+	return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
+}
+
+static void spi_gpio_chipselect(struct spi_device *dev, int on)
+{
+	struct spi_gpio *sp = spidev_to_sg(dev);
+
+	if (sp->info->cs_activelow)
+		on = !on;
+	gpio_set_value(sp->info->pin_cs, on ? 1 : 0);
+}
+
+static int spi_gpio_probe(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct spi_gpio_platform_data *pdata;
+	struct spi_gpio *sp;
+	struct spi_device *spidev;
+	int err;
+
+	pdata = pdev->dev.platform_data;
+	if (!pdata)
+		return -ENXIO;
+
+	err = -ENOMEM;
+	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_gpio));
+	if (!master)
+		goto err_alloc_master;
+
+	sp = spi_master_get_devdata(master);
+	platform_set_drvdata(pdev, sp);
+	sp->info = pdata;
+
+	err = gpio_request(pdata->pin_clk, "spi_clock");
+	if (err)
+		goto err_request_clk;
+	err = gpio_request(pdata->pin_mosi, "spi_mosi");
+	if (err)
+		goto err_request_mosi;
+	err = gpio_request(pdata->pin_miso, "spi_miso");
+	if (err)
+		goto err_request_miso;
+	err = gpio_request(pdata->pin_cs, "spi_cs");
+	if (err)
+		goto err_request_cs;
+
+	sp->bitbang.master = spi_master_get(master);
+	sp->bitbang.master->bus_num = -1;
+	sp->bitbang.master->num_chipselect = 1;
+	sp->bitbang.chipselect = spi_gpio_chipselect;
+	sp->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_mode0;
+	sp->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_mode1;
+	sp->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_mode2;
+	sp->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_mode3;
+
+	gpio_direction_output(pdata->pin_clk, 0);
+	gpio_direction_output(pdata->pin_mosi, 0);
+	gpio_direction_output(pdata->pin_cs,
+			      pdata->cs_activelow ? 1 : 0);
+	gpio_direction_input(pdata->pin_miso);
+
+	err = spi_bitbang_start(&sp->bitbang);
+	if (err)
+		goto err_no_bitbang;
+	err = pdata->boardinfo_setup(&sp->bi, master,
+				     pdata->boardinfo_setup_data);
+	if (err)
+		goto err_bi_setup;
+	sp->bi.controller_data = sp;
+	spidev = spi_new_device(master, &sp->bi);
+	if (!spidev)
+		goto err_new_dev;
+
+	return 0;
+
+err_new_dev:
+err_bi_setup:
+	spi_bitbang_stop(&sp->bitbang);
+err_no_bitbang:
+	spi_master_put(sp->bitbang.master);
+	gpio_free(pdata->pin_cs);
+err_request_cs:
+	gpio_free(pdata->pin_miso);
+err_request_miso:
+	gpio_free(pdata->pin_mosi);
+err_request_mosi:
+	gpio_free(pdata->pin_clk);
+err_request_clk:
+	kfree(master);
+
+err_alloc_master:
+	return err;
+}
+
+static int __devexit spi_gpio_remove(struct platform_device *pdev)
+{
+	struct spi_gpio *sp;
+	struct spi_gpio_platform_data *pdata;
+
+	pdata = pdev->dev.platform_data;
+	sp = platform_get_drvdata(pdev);
+
+	gpio_free(pdata->pin_clk);
+	gpio_free(pdata->pin_mosi);
+	gpio_free(pdata->pin_miso);
+	gpio_free(pdata->pin_cs);
+	spi_bitbang_stop(&sp->bitbang);
+	spi_master_put(sp->bitbang.master);
+
+	return 0;
+}
+
+static struct platform_driver spi_gpio_driver = {
+	.driver		= {
+		.name	= SPI_GPIO_PLATDEV_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= spi_gpio_probe,
+	.remove		= __devexit_p(spi_gpio_remove),
+};
+
+int spi_gpio_next_id(void)
+{
+	static atomic_t counter = ATOMIC_INIT(-1);
+
+	return atomic_inc_return(&counter);
+}
+EXPORT_SYMBOL(spi_gpio_next_id);
+
+static int __init spi_gpio_init(void)
+{
+	int err;
+
+	err = platform_driver_register(&spi_gpio_driver);
+	if (err)
+		printk(KERN_ERR "spi-gpio: register failed: %d\n", err);
+
+	return err;
+}
+module_init(spi_gpio_init);
+
+static void __exit spi_gpio_exit(void)
+{
+	platform_driver_unregister(&spi_gpio_driver);
+}
+module_exit(spi_gpio_exit);
+
+MODULE_AUTHOR("Piot Skamruk <piotr.skamruk at gmail.com>");
+MODULE_AUTHOR("Michael Buesch");
+MODULE_DESCRIPTION("Platform independent GPIO bitbanging SPI driver");
+MODULE_LICENSE("GPL v2");
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -133,6 +133,15 @@ config SPI_GPIO
 	  GPIO operations, you should be able to leverage that for better
 	  speed with a custom version of this driver; see the source code.
 
+config SPI_GPIO_OLD
+	tristate "Old GPIO API based bitbanging SPI controller (DEPRECATED)"
+	depends on SPI_MASTER && GENERIC_GPIO
+	select SPI_BITBANG
+	help
+	  This code is deprecated. Please use the new mainline SPI-GPIO driver.
+
+	  If unsure, say N.
+
 config SPI_IMX
 	tristate "Freescale i.MX SPI controllers"
 	depends on ARCH_MXC
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_SPI_DESIGNWARE)		+= dw_spi.
 obj-$(CONFIG_SPI_DW_PCI)		+= dw_spi_pci.o
 obj-$(CONFIG_SPI_DW_MMIO)		+= dw_spi_mmio.o
 obj-$(CONFIG_SPI_GPIO)			+= spi_gpio.o
+obj-$(CONFIG_SPI_GPIO_OLD)		+= spi_gpio_old.o
 obj-$(CONFIG_SPI_IMX)			+= spi_imx.o
 obj-$(CONFIG_SPI_LM70_LLP)		+= spi_lm70llp.o
 obj-$(CONFIG_SPI_PXA2XX)		+= pxa2xx_spi.o