Sonic Zhang | 35f6b6b | 2010-10-27 21:43:52 -0400 | [diff] [blame] | 1 | /* |
| 2 | * API bus driver for ADT7316/7/8 ADT7516/7/9 digital temperature |
| 3 | * sensor, ADC and DAC |
| 4 | * |
| 5 | * Copyright 2010 Analog Devices Inc. |
| 6 | * |
| 7 | * Licensed under the GPL-2 or later. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/device.h> |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/interrupt.h> |
| 14 | #include <linux/spi/spi.h> |
| 15 | |
| 16 | #include "adt7316.h" |
| 17 | |
| 18 | #define ADT7316_SPI_MAX_FREQ_HZ 5000000 |
| 19 | #define ADT7316_SPI_CMD_READ 0x91 |
| 20 | #define ADT7316_SPI_CMD_WRITE 0x90 |
| 21 | |
| 22 | /* |
| 23 | * adt7316 register access by SPI |
| 24 | */ |
| 25 | |
| 26 | static int adt7316_spi_multi_read(void *client, u8 reg, u8 count, u8 *data) |
| 27 | { |
| 28 | struct spi_device *spi_dev = client; |
| 29 | u8 cmd[2]; |
| 30 | int ret = 0; |
| 31 | |
| 32 | if (count > ADT7316_REG_MAX_ADDR) |
| 33 | count = ADT7316_REG_MAX_ADDR; |
| 34 | |
| 35 | cmd[0] = ADT7316_SPI_CMD_WRITE; |
| 36 | cmd[1] = reg; |
| 37 | |
| 38 | ret = spi_write(spi_dev, cmd, 2); |
| 39 | if (ret < 0) { |
| 40 | dev_err(&spi_dev->dev, "SPI fail to select reg\n"); |
| 41 | return ret; |
| 42 | } |
| 43 | |
| 44 | cmd[0] = ADT7316_SPI_CMD_READ; |
| 45 | |
| 46 | ret = spi_write_then_read(spi_dev, cmd, 1, data, count); |
| 47 | if (ret < 0) { |
| 48 | dev_err(&spi_dev->dev, "SPI read data error\n"); |
| 49 | return ret; |
| 50 | } |
| 51 | |
| 52 | return 0; |
| 53 | } |
| 54 | |
| 55 | static int adt7316_spi_multi_write(void *client, u8 reg, u8 count, u8 *data) |
| 56 | { |
| 57 | struct spi_device *spi_dev = client; |
| 58 | u8 buf[ADT7316_REG_MAX_ADDR + 2]; |
| 59 | int i, ret = 0; |
| 60 | |
| 61 | if (count > ADT7316_REG_MAX_ADDR) |
| 62 | count = ADT7316_REG_MAX_ADDR; |
| 63 | |
| 64 | buf[0] = ADT7316_SPI_CMD_WRITE; |
| 65 | buf[1] = reg; |
| 66 | for (i = 0; i < count; i++) |
| 67 | buf[i + 2] = data[i]; |
| 68 | |
| 69 | ret = spi_write(spi_dev, buf, count + 2); |
| 70 | if (ret < 0) { |
| 71 | dev_err(&spi_dev->dev, "SPI write error\n"); |
| 72 | return ret; |
| 73 | } |
| 74 | |
| 75 | return ret; |
| 76 | } |
| 77 | |
| 78 | static int adt7316_spi_read(void *client, u8 reg, u8 *data) |
| 79 | { |
| 80 | return adt7316_spi_multi_read(client, reg, 1, data); |
| 81 | } |
| 82 | |
| 83 | static int adt7316_spi_write(void *client, u8 reg, u8 val) |
| 84 | { |
| 85 | return adt7316_spi_multi_write(client, reg, 1, &val); |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * device probe and remove |
| 90 | */ |
| 91 | |
| 92 | static int __devinit adt7316_spi_probe(struct spi_device *spi_dev) |
| 93 | { |
| 94 | struct adt7316_bus bus = { |
| 95 | .client = spi_dev, |
| 96 | .irq = spi_dev->irq, |
| 97 | .irq_flags = IRQF_TRIGGER_LOW, |
| 98 | .read = adt7316_spi_read, |
| 99 | .write = adt7316_spi_write, |
| 100 | .multi_read = adt7316_spi_multi_read, |
| 101 | .multi_write = adt7316_spi_multi_write, |
| 102 | }; |
| 103 | |
| 104 | /* don't exceed max specified SPI CLK frequency */ |
| 105 | if (spi_dev->max_speed_hz > ADT7316_SPI_MAX_FREQ_HZ) { |
| 106 | dev_err(&spi_dev->dev, "SPI CLK %d Hz?\n", |
| 107 | spi_dev->max_speed_hz); |
| 108 | return -EINVAL; |
| 109 | } |
| 110 | |
| 111 | /* switch from default I2C protocol to SPI protocol */ |
| 112 | adt7316_spi_write(spi_dev, 0, 0); |
| 113 | adt7316_spi_write(spi_dev, 0, 0); |
| 114 | adt7316_spi_write(spi_dev, 0, 0); |
| 115 | |
| 116 | return adt7316_probe(&spi_dev->dev, &bus, spi_dev->modalias); |
| 117 | } |
| 118 | |
| 119 | static int __devexit adt7316_spi_remove(struct spi_device *spi_dev) |
| 120 | { |
| 121 | return adt7316_remove(&spi_dev->dev); |
| 122 | } |
| 123 | |
| 124 | static const struct spi_device_id adt7316_spi_id[] = { |
| 125 | { "adt7316", 0 }, |
| 126 | { "adt7317", 0 }, |
| 127 | { "adt7318", 0 }, |
| 128 | { "adt7516", 0 }, |
| 129 | { "adt7517", 0 }, |
| 130 | { "adt7519", 0 }, |
| 131 | { } |
| 132 | }; |
| 133 | |
| 134 | MODULE_DEVICE_TABLE(spi, adt7316_spi_id); |
| 135 | |
Sonic Zhang | 35f6b6b | 2010-10-27 21:43:52 -0400 | [diff] [blame] | 136 | static struct spi_driver adt7316_driver = { |
| 137 | .driver = { |
| 138 | .name = "adt7316", |
Lars-Peter Clausen | 01788c5 | 2012-02-20 19:37:05 +0100 | [diff] [blame] | 139 | .pm = ADT7316_PM_OPS, |
Sonic Zhang | 35f6b6b | 2010-10-27 21:43:52 -0400 | [diff] [blame] | 140 | .owner = THIS_MODULE, |
| 141 | }, |
| 142 | .probe = adt7316_spi_probe, |
| 143 | .remove = __devexit_p(adt7316_spi_remove), |
Sonic Zhang | 35f6b6b | 2010-10-27 21:43:52 -0400 | [diff] [blame] | 144 | .id_table = adt7316_spi_id, |
| 145 | }; |
Lars-Peter Clausen | ae6ae6f | 2011-11-16 10:13:39 +0100 | [diff] [blame] | 146 | module_spi_driver(adt7316_driver); |
Sonic Zhang | 35f6b6b | 2010-10-27 21:43:52 -0400 | [diff] [blame] | 147 | |
| 148 | MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>"); |
| 149 | MODULE_DESCRIPTION("SPI bus driver for Analog Devices ADT7316/7/8 and" |
| 150 | "ADT7516/7/9 digital temperature sensor, ADC and DAC"); |
| 151 | MODULE_LICENSE("GPL v2"); |