1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * AD714X CapTouch Programmable Controller driver (SPI bus)
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright 2009-2011 Analog Devices Inc.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/input.h> /* BUS_SPI */
9*4882a593Smuzhiyun #include <linux/module.h>
10*4882a593Smuzhiyun #include <linux/spi/spi.h>
11*4882a593Smuzhiyun #include <linux/pm.h>
12*4882a593Smuzhiyun #include <linux/types.h>
13*4882a593Smuzhiyun #include "ad714x.h"
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #define AD714x_SPI_CMD_PREFIX 0xE000 /* bits 15:11 */
16*4882a593Smuzhiyun #define AD714x_SPI_READ BIT(10)
17*4882a593Smuzhiyun
ad714x_spi_suspend(struct device * dev)18*4882a593Smuzhiyun static int __maybe_unused ad714x_spi_suspend(struct device *dev)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun return ad714x_disable(spi_get_drvdata(to_spi_device(dev)));
21*4882a593Smuzhiyun }
22*4882a593Smuzhiyun
ad714x_spi_resume(struct device * dev)23*4882a593Smuzhiyun static int __maybe_unused ad714x_spi_resume(struct device *dev)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun return ad714x_enable(spi_get_drvdata(to_spi_device(dev)));
26*4882a593Smuzhiyun }
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume);
29*4882a593Smuzhiyun
ad714x_spi_read(struct ad714x_chip * chip,unsigned short reg,unsigned short * data,size_t len)30*4882a593Smuzhiyun static int ad714x_spi_read(struct ad714x_chip *chip,
31*4882a593Smuzhiyun unsigned short reg, unsigned short *data, size_t len)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun struct spi_device *spi = to_spi_device(chip->dev);
34*4882a593Smuzhiyun struct spi_message message;
35*4882a593Smuzhiyun struct spi_transfer xfer[2];
36*4882a593Smuzhiyun int i;
37*4882a593Smuzhiyun int error;
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun spi_message_init(&message);
40*4882a593Smuzhiyun memset(xfer, 0, sizeof(xfer));
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX |
43*4882a593Smuzhiyun AD714x_SPI_READ | reg);
44*4882a593Smuzhiyun xfer[0].tx_buf = &chip->xfer_buf[0];
45*4882a593Smuzhiyun xfer[0].len = sizeof(chip->xfer_buf[0]);
46*4882a593Smuzhiyun spi_message_add_tail(&xfer[0], &message);
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun xfer[1].rx_buf = &chip->xfer_buf[1];
49*4882a593Smuzhiyun xfer[1].len = sizeof(chip->xfer_buf[1]) * len;
50*4882a593Smuzhiyun spi_message_add_tail(&xfer[1], &message);
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun error = spi_sync(spi, &message);
53*4882a593Smuzhiyun if (unlikely(error)) {
54*4882a593Smuzhiyun dev_err(chip->dev, "SPI read error: %d\n", error);
55*4882a593Smuzhiyun return error;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun for (i = 0; i < len; i++)
59*4882a593Smuzhiyun data[i] = be16_to_cpu(chip->xfer_buf[i + 1]);
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun return 0;
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun
ad714x_spi_write(struct ad714x_chip * chip,unsigned short reg,unsigned short data)64*4882a593Smuzhiyun static int ad714x_spi_write(struct ad714x_chip *chip,
65*4882a593Smuzhiyun unsigned short reg, unsigned short data)
66*4882a593Smuzhiyun {
67*4882a593Smuzhiyun struct spi_device *spi = to_spi_device(chip->dev);
68*4882a593Smuzhiyun int error;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | reg);
71*4882a593Smuzhiyun chip->xfer_buf[1] = cpu_to_be16(data);
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun error = spi_write(spi, (u8 *)chip->xfer_buf,
74*4882a593Smuzhiyun 2 * sizeof(*chip->xfer_buf));
75*4882a593Smuzhiyun if (unlikely(error)) {
76*4882a593Smuzhiyun dev_err(chip->dev, "SPI write error: %d\n", error);
77*4882a593Smuzhiyun return error;
78*4882a593Smuzhiyun }
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun return 0;
81*4882a593Smuzhiyun }
82*4882a593Smuzhiyun
ad714x_spi_probe(struct spi_device * spi)83*4882a593Smuzhiyun static int ad714x_spi_probe(struct spi_device *spi)
84*4882a593Smuzhiyun {
85*4882a593Smuzhiyun struct ad714x_chip *chip;
86*4882a593Smuzhiyun int err;
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun spi->bits_per_word = 8;
89*4882a593Smuzhiyun err = spi_setup(spi);
90*4882a593Smuzhiyun if (err < 0)
91*4882a593Smuzhiyun return err;
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq,
94*4882a593Smuzhiyun ad714x_spi_read, ad714x_spi_write);
95*4882a593Smuzhiyun if (IS_ERR(chip))
96*4882a593Smuzhiyun return PTR_ERR(chip);
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun spi_set_drvdata(spi, chip);
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun return 0;
101*4882a593Smuzhiyun }
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun static struct spi_driver ad714x_spi_driver = {
104*4882a593Smuzhiyun .driver = {
105*4882a593Smuzhiyun .name = "ad714x_captouch",
106*4882a593Smuzhiyun .pm = &ad714x_spi_pm,
107*4882a593Smuzhiyun },
108*4882a593Smuzhiyun .probe = ad714x_spi_probe,
109*4882a593Smuzhiyun };
110*4882a593Smuzhiyun
111*4882a593Smuzhiyun module_spi_driver(ad714x_spi_driver);
112*4882a593Smuzhiyun
113*4882a593Smuzhiyun MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver");
114*4882a593Smuzhiyun MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
115*4882a593Smuzhiyun MODULE_LICENSE("GPL");
116