1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * AD714X CapTouch Programmable Controller driver (SPI bus) |
4 | * |
5 | * Copyright 2009-2011 Analog Devices Inc. |
6 | */ |
7 | |
8 | #include <linux/input.h> /* BUS_SPI */ |
9 | #include <linux/module.h> |
10 | #include <linux/spi/spi.h> |
11 | #include <linux/pm.h> |
12 | #include <linux/types.h> |
13 | #include "ad714x.h" |
14 | |
15 | #define AD714x_SPI_CMD_PREFIX 0xE000 /* bits 15:11 */ |
16 | #define AD714x_SPI_READ BIT(10) |
17 | |
18 | static int ad714x_spi_read(struct ad714x_chip *chip, |
19 | unsigned short reg, unsigned short *data, size_t len) |
20 | { |
21 | struct spi_device *spi = to_spi_device(dev: chip->dev); |
22 | struct spi_message message; |
23 | struct spi_transfer xfer[2]; |
24 | int i; |
25 | int error; |
26 | |
27 | spi_message_init(m: &message); |
28 | memset(xfer, 0, sizeof(xfer)); |
29 | |
30 | chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | |
31 | AD714x_SPI_READ | reg); |
32 | xfer[0].tx_buf = &chip->xfer_buf[0]; |
33 | xfer[0].len = sizeof(chip->xfer_buf[0]); |
34 | spi_message_add_tail(t: &xfer[0], m: &message); |
35 | |
36 | xfer[1].rx_buf = &chip->xfer_buf[1]; |
37 | xfer[1].len = sizeof(chip->xfer_buf[1]) * len; |
38 | spi_message_add_tail(t: &xfer[1], m: &message); |
39 | |
40 | error = spi_sync(spi, message: &message); |
41 | if (unlikely(error)) { |
42 | dev_err(chip->dev, "SPI read error: %d\n" , error); |
43 | return error; |
44 | } |
45 | |
46 | for (i = 0; i < len; i++) |
47 | data[i] = be16_to_cpu(chip->xfer_buf[i + 1]); |
48 | |
49 | return 0; |
50 | } |
51 | |
52 | static int ad714x_spi_write(struct ad714x_chip *chip, |
53 | unsigned short reg, unsigned short data) |
54 | { |
55 | struct spi_device *spi = to_spi_device(dev: chip->dev); |
56 | int error; |
57 | |
58 | chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | reg); |
59 | chip->xfer_buf[1] = cpu_to_be16(data); |
60 | |
61 | error = spi_write(spi, buf: (u8 *)chip->xfer_buf, |
62 | len: 2 * sizeof(*chip->xfer_buf)); |
63 | if (unlikely(error)) { |
64 | dev_err(chip->dev, "SPI write error: %d\n" , error); |
65 | return error; |
66 | } |
67 | |
68 | return 0; |
69 | } |
70 | |
71 | static int ad714x_spi_probe(struct spi_device *spi) |
72 | { |
73 | struct ad714x_chip *chip; |
74 | int err; |
75 | |
76 | spi->bits_per_word = 8; |
77 | err = spi_setup(spi); |
78 | if (err < 0) |
79 | return err; |
80 | |
81 | chip = ad714x_probe(dev: &spi->dev, BUS_SPI, irq: spi->irq, |
82 | read: ad714x_spi_read, write: ad714x_spi_write); |
83 | if (IS_ERR(ptr: chip)) |
84 | return PTR_ERR(ptr: chip); |
85 | |
86 | spi_set_drvdata(spi, data: chip); |
87 | |
88 | return 0; |
89 | } |
90 | |
91 | static struct spi_driver ad714x_spi_driver = { |
92 | .driver = { |
93 | .name = "ad714x_captouch" , |
94 | .pm = pm_sleep_ptr(&ad714x_pm), |
95 | }, |
96 | .probe = ad714x_spi_probe, |
97 | }; |
98 | |
99 | module_spi_driver(ad714x_spi_driver); |
100 | |
101 | MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver" ); |
102 | MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>" ); |
103 | MODULE_LICENSE("GPL" ); |
104 | |