1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Driver for Freescale's 3-Axis Accelerometer MMA8450 4 * 5 * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved. 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/slab.h> 11 #include <linux/delay.h> 12 #include <linux/i2c.h> 13 #include <linux/input.h> 14 #include <linux/of_device.h> 15 16 #define MMA8450_DRV_NAME "mma8450" 17 18 #define MODE_CHANGE_DELAY_MS 100 19 #define POLL_INTERVAL 100 20 #define POLL_INTERVAL_MAX 500 21 22 /* register definitions */ 23 #define MMA8450_STATUS 0x00 24 #define MMA8450_STATUS_ZXYDR 0x08 25 26 #define MMA8450_OUT_X8 0x01 27 #define MMA8450_OUT_Y8 0x02 28 #define MMA8450_OUT_Z8 0x03 29 30 #define MMA8450_OUT_X_LSB 0x05 31 #define MMA8450_OUT_X_MSB 0x06 32 #define MMA8450_OUT_Y_LSB 0x07 33 #define MMA8450_OUT_Y_MSB 0x08 34 #define MMA8450_OUT_Z_LSB 0x09 35 #define MMA8450_OUT_Z_MSB 0x0a 36 37 #define MMA8450_XYZ_DATA_CFG 0x16 38 39 #define MMA8450_CTRL_REG1 0x38 40 #define MMA8450_CTRL_REG2 0x39 41 42 static int mma8450_read(struct i2c_client *c, unsigned int off) 43 { 44 int ret; 45 46 ret = i2c_smbus_read_byte_data(c, off); 47 if (ret < 0) 48 dev_err(&c->dev, 49 "failed to read register 0x%02x, error %d\n", 50 off, ret); 51 52 return ret; 53 } 54 55 static int mma8450_write(struct i2c_client *c, unsigned int off, u8 v) 56 { 57 int error; 58 59 error = i2c_smbus_write_byte_data(c, off, v); 60 if (error < 0) { 61 dev_err(&c->dev, 62 "failed to write to register 0x%02x, error %d\n", 63 off, error); 64 return error; 65 } 66 67 return 0; 68 } 69 70 static int mma8450_read_block(struct i2c_client *c, unsigned int off, 71 u8 *buf, size_t size) 72 { 73 int err; 74 75 err = i2c_smbus_read_i2c_block_data(c, off, size, buf); 76 if (err < 0) { 77 dev_err(&c->dev, 78 "failed to read block data at 0x%02x, error %d\n", 79 MMA8450_OUT_X_LSB, err); 80 return err; 81 } 82 83 return 0; 84 } 85 86 static void mma8450_poll(struct input_dev *input) 87 { 88 struct i2c_client *c = input_get_drvdata(input); 89 int x, y, z; 90 int ret; 91 u8 buf[6]; 92 93 ret = mma8450_read(c, MMA8450_STATUS); 94 if (ret < 0) 95 return; 96 97 if (!(ret & MMA8450_STATUS_ZXYDR)) 98 return; 99 100 ret = mma8450_read_block(c, MMA8450_OUT_X_LSB, buf, sizeof(buf)); 101 if (ret < 0) 102 return; 103 104 x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf); 105 y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf); 106 z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf); 107 108 input_report_abs(input, ABS_X, x); 109 input_report_abs(input, ABS_Y, y); 110 input_report_abs(input, ABS_Z, z); 111 input_sync(input); 112 } 113 114 /* Initialize the MMA8450 chip */ 115 static int mma8450_open(struct input_dev *input) 116 { 117 struct i2c_client *c = input_get_drvdata(input); 118 int err; 119 120 /* enable all events from X/Y/Z, no FIFO */ 121 err = mma8450_write(c, MMA8450_XYZ_DATA_CFG, 0x07); 122 if (err) 123 return err; 124 125 /* 126 * Sleep mode poll rate - 50Hz 127 * System output data rate - 400Hz 128 * Full scale selection - Active, +/- 2G 129 */ 130 err = mma8450_write(c, MMA8450_CTRL_REG1, 0x01); 131 if (err) 132 return err; 133 134 msleep(MODE_CHANGE_DELAY_MS); 135 return 0; 136 } 137 138 static void mma8450_close(struct input_dev *input) 139 { 140 struct i2c_client *c = input_get_drvdata(input); 141 142 mma8450_write(c, MMA8450_CTRL_REG1, 0x00); 143 mma8450_write(c, MMA8450_CTRL_REG2, 0x01); 144 } 145 146 /* 147 * I2C init/probing/exit functions 148 */ 149 static int mma8450_probe(struct i2c_client *c) 150 { 151 struct input_dev *input; 152 int err; 153 154 input = devm_input_allocate_device(&c->dev); 155 if (!input) 156 return -ENOMEM; 157 158 input_set_drvdata(input, c); 159 160 input->name = MMA8450_DRV_NAME; 161 input->id.bustype = BUS_I2C; 162 163 input->open = mma8450_open; 164 input->close = mma8450_close; 165 166 input_set_abs_params(input, ABS_X, -2048, 2047, 32, 32); 167 input_set_abs_params(input, ABS_Y, -2048, 2047, 32, 32); 168 input_set_abs_params(input, ABS_Z, -2048, 2047, 32, 32); 169 170 err = input_setup_polling(input, mma8450_poll); 171 if (err) { 172 dev_err(&c->dev, "failed to set up polling\n"); 173 return err; 174 } 175 176 input_set_poll_interval(input, POLL_INTERVAL); 177 input_set_max_poll_interval(input, POLL_INTERVAL_MAX); 178 179 err = input_register_device(input); 180 if (err) { 181 dev_err(&c->dev, "failed to register input device\n"); 182 return err; 183 } 184 185 return 0; 186 } 187 188 static const struct i2c_device_id mma8450_id[] = { 189 { MMA8450_DRV_NAME, 0 }, 190 { }, 191 }; 192 MODULE_DEVICE_TABLE(i2c, mma8450_id); 193 194 static const struct of_device_id mma8450_dt_ids[] = { 195 { .compatible = "fsl,mma8450", }, 196 { /* sentinel */ } 197 }; 198 MODULE_DEVICE_TABLE(of, mma8450_dt_ids); 199 200 static struct i2c_driver mma8450_driver = { 201 .driver = { 202 .name = MMA8450_DRV_NAME, 203 .of_match_table = mma8450_dt_ids, 204 }, 205 .probe_new = mma8450_probe, 206 .id_table = mma8450_id, 207 }; 208 209 module_i2c_driver(mma8450_driver); 210 211 MODULE_AUTHOR("Freescale Semiconductor, Inc."); 212 MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver"); 213 MODULE_LICENSE("GPL"); 214