aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/xburst/patches-2.6.35/400-spi-gpio-3wire.patch
blob: d60a851347a7f0b3ea0929a8a5722114a721b6ef (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
From 62b6a295d39417293adcc81dc36b7edc56546814 Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Sat, 24 Apr 2010 12:23:01 +0200
Subject: [PATCH] gpio spi 3wire

---
 drivers/spi/spi_bitbang.c       |    2 +
 drivers/spi/spi_gpio.c          |   60 ++++++++++++++++++++++++++------------
 include/linux/spi/spi_bitbang.h |    2 +
 3 files changed, 45 insertions(+), 19 deletions(-)

--- a/drivers/spi/spi_bitbang.c
+++ b/drivers/spi/spi_bitbang.c
@@ -335,6 +335,8 @@ static void bitbang_work(struct work_str
 				 */
 				if (!m->is_dma_mapped)
 					t->rx_dma = t->tx_dma = 0;
+				if ((spi->mode & SPI_3WIRE) && bitbang->set_direction)
+					bitbang->set_direction(spi, t->tx_buf != NULL);
 				status = bitbang->txrx_bufs(spi, t);
 			}
 			if (status > 0)
--- a/drivers/spi/spi_gpio.c
+++ b/drivers/spi/spi_gpio.c
@@ -46,6 +46,8 @@ struct spi_gpio {
 	struct spi_bitbang		bitbang;
 	struct spi_gpio_platform_data	pdata;
 	struct platform_device		*pdev;
+
+	int miso_pin;
 };
 
 /*----------------------------------------------------------------------*/
@@ -91,19 +93,16 @@ struct spi_gpio {
 
 /*----------------------------------------------------------------------*/
 
-static inline const struct spi_gpio_platform_data * __pure
-spi_to_pdata(const struct spi_device *spi)
+static inline const struct spi_gpio * __pure
+spi_to_spi_gpio(const struct spi_device *spi)
 {
 	const struct spi_bitbang	*bang;
-	const struct spi_gpio		*spi_gpio;
 
 	bang = spi_master_get_devdata(spi->master);
-	spi_gpio = container_of(bang, struct spi_gpio, bitbang);
-	return &spi_gpio->pdata;
+	return container_of(bang, struct spi_gpio, bitbang);
 }
 
-/* this is #defined to avoid unused-variable warnings when inlining */
-#define pdata		spi_to_pdata(spi)
+#define pdata &(spi_to_spi_gpio(spi)->pdata)
 
 static inline void setsck(const struct spi_device *spi, int is_on)
 {
@@ -117,10 +116,9 @@ static inline void setmosi(const struct 
 
 static inline int getmiso(const struct spi_device *spi)
 {
-	return !!gpio_get_value(SPI_MISO_GPIO);
+	return !!gpio_get_value(spi_to_spi_gpio(spi)->miso_pin);
 }
 
-#undef pdata
 
 /*
  * NOTE:  to clock "as fast as we can", set spi_device.max_speed_hz
@@ -183,10 +181,16 @@ static u32 spi_gpio_txrx_word_mode3(stru
 static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
 {
 	unsigned long cs = (unsigned long) spi->controller_data;
+	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
 
 	/* set initial clock polarity */
-	if (is_active)
+	if (is_active) {
 		setsck(spi, spi->mode & SPI_CPOL);
+		if (spi->mode & SPI_3WIRE)
+			spi_gpio->miso_pin = SPI_MOSI_GPIO;
+		else
+			spi_gpio->miso_pin = SPI_MISO_GPIO;
+	}
 
 	if (cs != SPI_GPIO_NO_CHIPSELECT) {
 		/* SPI is normally active-low */
@@ -202,6 +206,9 @@ static int spi_gpio_setup(struct spi_dev
 	if (spi->bits_per_word > 32)
 		return -EINVAL;
 
+	if (!(spi->mode & SPI_3WIRE) && !gpio_is_valid(SPI_MISO_GPIO))
+		return -EINVAL;
+
 	if (!spi->controller_state) {
 		if (cs != SPI_GPIO_NO_CHIPSELECT) {
 			status = gpio_request(cs, dev_name(&spi->dev));
@@ -219,6 +226,16 @@ static int spi_gpio_setup(struct spi_dev
 	return status;
 }
 
+static void spi_gpio_set_direction(struct spi_device *spi, bool is_tx)
+{
+	if (is_tx)
+		gpio_direction_output(SPI_MISO_GPIO, 0);
+	else
+		gpio_direction_input(SPI_MISO_GPIO);
+}
+
+#undef pdata
+
 static void spi_gpio_cleanup(struct spi_device *spi)
 {
 	unsigned long	cs = (unsigned long) spi->controller_data;
@@ -253,18 +270,20 @@ spi_gpio_request(struct spi_gpio_platfor
 	if (value)
 		goto done;
 
-	value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
+	value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
 	if (value)
 		goto free_mosi;
 
-	value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
-	if (value)
-		goto free_miso;
+	if (gpio_is_valid(SPI_MISO_GPIO)) {
+		value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
+		if (value)
+			goto free_sck;
+	}
 
 	goto done;
 
-free_miso:
-	gpio_free(SPI_MISO_GPIO);
+free_sck:
+	gpio_free(SPI_SCK_GPIO);
 free_mosi:
 	gpio_free(SPI_MOSI_GPIO);
 done:
@@ -312,13 +331,15 @@ static int __devinit spi_gpio_probe(stru
 	spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
 	spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
 	spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
-	spi_gpio->bitbang.flags = SPI_CS_HIGH;
+	spi_gpio->bitbang.set_direction = spi_gpio_set_direction;
+	spi_gpio->bitbang.flags = SPI_CS_HIGH | SPI_3WIRE;
 
 	status = spi_bitbang_start(&spi_gpio->bitbang);
 	if (status < 0) {
 		spi_master_put(spi_gpio->bitbang.master);
 gpio_free:
-		gpio_free(SPI_MISO_GPIO);
+		if (gpio_is_valid(SPI_MOSI_GPIO))
+			gpio_free(SPI_MISO_GPIO);
 		gpio_free(SPI_MOSI_GPIO);
 		gpio_free(SPI_SCK_GPIO);
 		spi_master_put(master);
@@ -342,7 +363,8 @@ static int __devexit spi_gpio_remove(str
 
 	platform_set_drvdata(pdev, NULL);
 
-	gpio_free(SPI_MISO_GPIO);
+	if (gpio_is_valid(SPI_MISO_GPIO))
+		gpio_free(SPI_MISO_GPIO);
 	gpio_free(SPI_MOSI_GPIO);
 	gpio_free(SPI_SCK_GPIO);
 
--- a/include/linux/spi/spi_bitbang.h
+++ b/include/linux/spi/spi_bitbang.h
@@ -34,6 +34,8 @@ struct spi_bitbang {
 	u32	(*txrx_word[4])(struct spi_device *spi,
 			unsigned nsecs,
 			u32 word, u8 bits);
+
+	void (*set_direction)(struct spi_device *, bool is_tx);
 };
 
 /* you can call these default bitbang->master methods from your custom