1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Samsung LSI S5C73M3 8M pixel camera driver
4  *
5  * Copyright (C) 2012, Samsung Electronics, Co., Ltd.
6  * Sylwester Nawrocki <s.nawrocki@samsung.com>
7  * Andrzej Hajda <a.hajda@samsung.com>
8  */
9 
10 #include <linux/sizes.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/media.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/spi/spi.h>
17 
18 #include "s5c73m3.h"
19 
20 #define S5C73M3_SPI_DRV_NAME "S5C73M3-SPI"
21 
22 static const struct of_device_id s5c73m3_spi_ids[] = {
23 	{ .compatible = "samsung,s5c73m3" },
24 	{ }
25 };
26 MODULE_DEVICE_TABLE(of, s5c73m3_spi_ids);
27 
28 enum spi_direction {
29 	SPI_DIR_RX,
30 	SPI_DIR_TX
31 };
32 
33 static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len,
34 							enum spi_direction dir)
35 {
36 	struct spi_message msg;
37 	int r;
38 	struct spi_transfer xfer = {
39 		.len	= len,
40 	};
41 
42 	if (dir == SPI_DIR_TX)
43 		xfer.tx_buf = addr;
44 	else
45 		xfer.rx_buf = addr;
46 
47 	if (spi_dev == NULL) {
48 		pr_err("SPI device is uninitialized\n");
49 		return -ENODEV;
50 	}
51 
52 	spi_message_init(&msg);
53 	spi_message_add_tail(&xfer, &msg);
54 
55 	r = spi_sync(spi_dev, &msg);
56 	if (r < 0)
57 		dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r);
58 
59 	return r;
60 }
61 
62 int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr,
63 		      const unsigned int len, const unsigned int tx_size)
64 {
65 	struct spi_device *spi_dev = state->spi_dev;
66 	u32 count = len / tx_size;
67 	u32 extra = len % tx_size;
68 	unsigned int i, j = 0;
69 	u8 padding[32];
70 	int r = 0;
71 
72 	memset(padding, 0, sizeof(padding));
73 
74 	for (i = 0; i < count; i++) {
75 		r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX);
76 		if (r < 0)
77 			return r;
78 		j += tx_size;
79 	}
80 
81 	if (extra > 0) {
82 		r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX);
83 		if (r < 0)
84 			return r;
85 	}
86 
87 	return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX);
88 }
89 
90 int s5c73m3_spi_read(struct s5c73m3 *state, void *addr,
91 		     const unsigned int len, const unsigned int tx_size)
92 {
93 	struct spi_device *spi_dev = state->spi_dev;
94 	u32 count = len / tx_size;
95 	u32 extra = len % tx_size;
96 	unsigned int i, j = 0;
97 	int r = 0;
98 
99 	for (i = 0; i < count; i++) {
100 		r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX);
101 		if (r < 0)
102 			return r;
103 		j += tx_size;
104 	}
105 
106 	if (extra > 0)
107 		return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX);
108 
109 	return 0;
110 }
111 
112 static int s5c73m3_spi_probe(struct spi_device *spi)
113 {
114 	int r;
115 	struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3,
116 					     spidrv.driver);
117 	spi->bits_per_word = 32;
118 
119 	r = spi_setup(spi);
120 	if (r < 0) {
121 		dev_err(&spi->dev, "spi_setup() failed\n");
122 		return r;
123 	}
124 
125 	mutex_lock(&state->lock);
126 	state->spi_dev = spi;
127 	mutex_unlock(&state->lock);
128 
129 	v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n");
130 	return 0;
131 }
132 
133 int s5c73m3_register_spi_driver(struct s5c73m3 *state)
134 {
135 	struct spi_driver *spidrv = &state->spidrv;
136 
137 	spidrv->probe = s5c73m3_spi_probe;
138 	spidrv->driver.name = S5C73M3_SPI_DRV_NAME;
139 	spidrv->driver.of_match_table = s5c73m3_spi_ids;
140 
141 	return spi_register_driver(spidrv);
142 }
143 
144 void s5c73m3_unregister_spi_driver(struct s5c73m3 *state)
145 {
146 	spi_unregister_driver(&state->spidrv);
147 }
148