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4065d1e7 JMC |
1 | /* |
2 | * Source for: | |
3 | * Cypress TrueTouch(TM) Standard Product (TTSP) SPI touchscreen driver. | |
4 | * For use with Cypress Txx3xx parts. | |
5 | * Supported parts include: | |
6 | * CY8CTST341 | |
7 | * CY8CTMA340 | |
8 | * | |
9 | * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc. | |
10 | * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org> | |
9664877e | 11 | * Copyright (C) 2013 Cypress Semiconductor |
4065d1e7 JMC |
12 | * |
13 | * This program is free software; you can redistribute it and/or | |
14 | * modify it under the terms of the GNU General Public License | |
15 | * version 2, and only version 2, as published by the | |
16 | * Free Software Foundation. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | * | |
9664877e | 23 | * Contact Cypress Semiconductor at www.cypress.com <ttdrivers@cypress.com> |
4065d1e7 JMC |
24 | * |
25 | */ | |
26 | ||
27 | #include "cyttsp_core.h" | |
28 | ||
29 | #include <linux/delay.h> | |
30 | #include <linux/input.h> | |
31 | #include <linux/spi/spi.h> | |
32 | ||
33 | #define CY_SPI_WR_OP 0x00 /* r/~w */ | |
34 | #define CY_SPI_RD_OP 0x01 | |
35 | #define CY_SPI_CMD_BYTES 4 | |
36 | #define CY_SPI_SYNC_BYTE 2 | |
37 | #define CY_SPI_SYNC_ACK1 0x62 /* from protocol v.2 */ | |
38 | #define CY_SPI_SYNC_ACK2 0x9D /* from protocol v.2 */ | |
39 | #define CY_SPI_DATA_SIZE 128 | |
40 | #define CY_SPI_DATA_BUF_SIZE (CY_SPI_CMD_BYTES + CY_SPI_DATA_SIZE) | |
41 | #define CY_SPI_BITS_PER_WORD 8 | |
42 | ||
9664877e | 43 | static int cyttsp_spi_xfer(struct device *dev, u8 *xfer_buf, |
62f548d0 | 44 | u8 op, u16 reg, u8 *buf, int length) |
4065d1e7 | 45 | { |
9664877e | 46 | struct spi_device *spi = to_spi_device(dev); |
4065d1e7 JMC |
47 | struct spi_message msg; |
48 | struct spi_transfer xfer[2]; | |
9664877e FY |
49 | u8 *wr_buf = &xfer_buf[0]; |
50 | u8 *rd_buf = &xfer_buf[CY_SPI_DATA_BUF_SIZE]; | |
4065d1e7 JMC |
51 | int retval; |
52 | int i; | |
53 | ||
54 | if (length > CY_SPI_DATA_SIZE) { | |
9664877e | 55 | dev_err(dev, "%s: length %d is too big.\n", |
4065d1e7 JMC |
56 | __func__, length); |
57 | return -EINVAL; | |
58 | } | |
59 | ||
60 | memset(wr_buf, 0, CY_SPI_DATA_BUF_SIZE); | |
61 | memset(rd_buf, 0, CY_SPI_DATA_BUF_SIZE); | |
62 | ||
63 | wr_buf[0] = 0x00; /* header byte 0 */ | |
64 | wr_buf[1] = 0xFF; /* header byte 1 */ | |
65 | wr_buf[2] = reg; /* reg index */ | |
66 | wr_buf[3] = op; /* r/~w */ | |
67 | if (op == CY_SPI_WR_OP) | |
68 | memcpy(wr_buf + CY_SPI_CMD_BYTES, buf, length); | |
69 | ||
70 | memset(xfer, 0, sizeof(xfer)); | |
71 | spi_message_init(&msg); | |
72 | ||
73 | /* | |
74 | We set both TX and RX buffers because Cypress TTSP | |
75 | requires full duplex operation. | |
76 | */ | |
77 | xfer[0].tx_buf = wr_buf; | |
78 | xfer[0].rx_buf = rd_buf; | |
79 | switch (op) { | |
80 | case CY_SPI_WR_OP: | |
81 | xfer[0].len = length + CY_SPI_CMD_BYTES; | |
82 | spi_message_add_tail(&xfer[0], &msg); | |
83 | break; | |
84 | ||
85 | case CY_SPI_RD_OP: | |
86 | xfer[0].len = CY_SPI_CMD_BYTES; | |
87 | spi_message_add_tail(&xfer[0], &msg); | |
88 | ||
89 | xfer[1].rx_buf = buf; | |
90 | xfer[1].len = length; | |
91 | spi_message_add_tail(&xfer[1], &msg); | |
92 | break; | |
93 | ||
94 | default: | |
9664877e | 95 | dev_err(dev, "%s: bad operation code=%d\n", __func__, op); |
4065d1e7 JMC |
96 | return -EINVAL; |
97 | } | |
98 | ||
99 | retval = spi_sync(spi, &msg); | |
100 | if (retval < 0) { | |
9664877e | 101 | dev_dbg(dev, "%s: spi_sync() error %d, len=%d, op=%d\n", |
4065d1e7 JMC |
102 | __func__, retval, xfer[1].len, op); |
103 | ||
104 | /* | |
105 | * do not return here since was a bad ACK sequence | |
106 | * let the following ACK check handle any errors and | |
107 | * allow silent retries | |
108 | */ | |
109 | } | |
110 | ||
111 | if (rd_buf[CY_SPI_SYNC_BYTE] != CY_SPI_SYNC_ACK1 || | |
112 | rd_buf[CY_SPI_SYNC_BYTE + 1] != CY_SPI_SYNC_ACK2) { | |
9664877e | 113 | dev_dbg(dev, "%s: operation %d failed\n", __func__, op); |
4065d1e7 JMC |
114 | |
115 | for (i = 0; i < CY_SPI_CMD_BYTES; i++) | |
9664877e | 116 | dev_dbg(dev, "%s: test rd_buf[%d]:0x%02x\n", |
4065d1e7 JMC |
117 | __func__, i, rd_buf[i]); |
118 | for (i = 0; i < length; i++) | |
9664877e | 119 | dev_dbg(dev, "%s: test buf[%d]:0x%02x\n", |
4065d1e7 JMC |
120 | __func__, i, buf[i]); |
121 | ||
122 | return -EIO; | |
123 | } | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
9664877e | 128 | static int cyttsp_spi_read_block_data(struct device *dev, u8 *xfer_buf, |
62f548d0 | 129 | u16 addr, u8 length, void *data) |
4065d1e7 | 130 | { |
9664877e FY |
131 | return cyttsp_spi_xfer(dev, xfer_buf, CY_SPI_RD_OP, addr, data, |
132 | length); | |
4065d1e7 JMC |
133 | } |
134 | ||
9664877e | 135 | static int cyttsp_spi_write_block_data(struct device *dev, u8 *xfer_buf, |
62f548d0 | 136 | u16 addr, u8 length, const void *data) |
4065d1e7 | 137 | { |
9664877e FY |
138 | return cyttsp_spi_xfer(dev, xfer_buf, CY_SPI_WR_OP, addr, (void *)data, |
139 | length); | |
4065d1e7 JMC |
140 | } |
141 | ||
142 | static const struct cyttsp_bus_ops cyttsp_spi_bus_ops = { | |
143 | .bustype = BUS_SPI, | |
144 | .write = cyttsp_spi_write_block_data, | |
145 | .read = cyttsp_spi_read_block_data, | |
146 | }; | |
147 | ||
5298cc4c | 148 | static int cyttsp_spi_probe(struct spi_device *spi) |
4065d1e7 JMC |
149 | { |
150 | struct cyttsp *ts; | |
151 | int error; | |
152 | ||
153 | /* Set up SPI*/ | |
154 | spi->bits_per_word = CY_SPI_BITS_PER_WORD; | |
155 | spi->mode = SPI_MODE_0; | |
156 | error = spi_setup(spi); | |
157 | if (error < 0) { | |
158 | dev_err(&spi->dev, "%s: SPI setup error %d\n", | |
159 | __func__, error); | |
160 | return error; | |
161 | } | |
162 | ||
163 | ts = cyttsp_probe(&cyttsp_spi_bus_ops, &spi->dev, spi->irq, | |
164 | CY_SPI_DATA_BUF_SIZE * 2); | |
165 | if (IS_ERR(ts)) | |
166 | return PTR_ERR(ts); | |
167 | ||
168 | spi_set_drvdata(spi, ts); | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
4065d1e7 JMC |
173 | static struct spi_driver cyttsp_spi_driver = { |
174 | .driver = { | |
175 | .name = CY_SPI_NAME, | |
4065d1e7 JMC |
176 | .pm = &cyttsp_pm_ops, |
177 | }, | |
178 | .probe = cyttsp_spi_probe, | |
4065d1e7 JMC |
179 | }; |
180 | ||
ca83922e | 181 | module_spi_driver(cyttsp_spi_driver); |
4065d1e7 | 182 | |
4065d1e7 JMC |
183 | MODULE_LICENSE("GPL"); |
184 | MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard Product (TTSP) SPI driver"); | |
185 | MODULE_AUTHOR("Cypress"); | |
186 | MODULE_ALIAS("spi:cyttsp"); |