1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * LM8333 keypad driver 4 * Copyright (C) 2012 Wolfram Sang, Pengutronix <kernel@pengutronix.de> 5 */ 6 7#include <linux/i2c.h> 8#include <linux/input.h> 9#include <linux/input/matrix_keypad.h> 10#include <linux/input/lm8333.h> 11#include <linux/interrupt.h> 12#include <linux/module.h> 13#include <linux/slab.h> 14 15#define LM8333_FIFO_READ 0x20 16#define LM8333_DEBOUNCE 0x22 17#define LM8333_READ_INT 0xD0 18#define LM8333_ACTIVE 0xE4 19#define LM8333_READ_ERROR 0xF0 20 21#define LM8333_KEYPAD_IRQ (1 << 0) 22#define LM8333_ERROR_IRQ (1 << 3) 23 24#define LM8333_ERROR_KEYOVR 0x04 25#define LM8333_ERROR_FIFOOVR 0x40 26 27#define LM8333_FIFO_TRANSFER_SIZE 16 28 29#define LM8333_NUM_ROWS 8 30#define LM8333_NUM_COLS 16 31#define LM8333_ROW_SHIFT 4 32 33struct lm8333 { 34 struct i2c_client *client; 35 struct input_dev *input; 36 unsigned short keycodes[LM8333_NUM_ROWS << LM8333_ROW_SHIFT]; 37}; 38 39/* The accessors try twice because the first access may be needed for wakeup */ 40#define LM8333_READ_RETRIES 2 41 42int lm8333_read8(struct lm8333 *lm8333, u8 cmd) 43{ 44 int retries = 0, ret; 45 46 do { 47 ret = i2c_smbus_read_byte_data(lm8333->client, cmd); 48 } while (ret < 0 && retries++ < LM8333_READ_RETRIES); 49 50 return ret; 51} 52 53int lm8333_write8(struct lm8333 *lm8333, u8 cmd, u8 val) 54{ 55 int retries = 0, ret; 56 57 do { 58 ret = i2c_smbus_write_byte_data(lm8333->client, cmd, val); 59 } while (ret < 0 && retries++ < LM8333_READ_RETRIES); 60 61 return ret; 62} 63 64int lm8333_read_block(struct lm8333 *lm8333, u8 cmd, u8 len, u8 *buf) 65{ 66 int retries = 0, ret; 67 68 do { 69 ret = i2c_smbus_read_i2c_block_data(lm8333->client, 70 cmd, len, buf); 71 } while (ret < 0 && retries++ < LM8333_READ_RETRIES); 72 73 return ret; 74} 75 76static void lm8333_key_handler(struct lm8333 *lm8333) 77{ 78 struct input_dev *input = lm8333->input; 79 u8 keys[LM8333_FIFO_TRANSFER_SIZE]; 80 u8 code, pressed; 81 int i, ret; 82 83 ret = lm8333_read_block(lm8333, LM8333_FIFO_READ, 84 LM8333_FIFO_TRANSFER_SIZE, keys); 85 if (ret != LM8333_FIFO_TRANSFER_SIZE) { 86 dev_err(&lm8333->client->dev, 87 "Error %d while reading FIFO\n", ret); 88 return; 89 } 90 91 for (i = 0; i < LM8333_FIFO_TRANSFER_SIZE && keys[i]; i++) { 92 pressed = keys[i] & 0x80; 93 code = keys[i] & 0x7f; 94 95 input_event(input, EV_MSC, MSC_SCAN, code); 96 input_report_key(input, lm8333->keycodes[code], pressed); 97 } 98 99 input_sync(input); 100} 101 102static irqreturn_t lm8333_irq_thread(int irq, void *data) 103{ 104 struct lm8333 *lm8333 = data; 105 u8 status = lm8333_read8(lm8333, LM8333_READ_INT); 106 107 if (!status) 108 return IRQ_NONE; 109 110 if (status & LM8333_ERROR_IRQ) { 111 u8 err = lm8333_read8(lm8333, LM8333_READ_ERROR); 112 113 if (err & (LM8333_ERROR_KEYOVR | LM8333_ERROR_FIFOOVR)) { 114 u8 dummy[LM8333_FIFO_TRANSFER_SIZE]; 115 116 lm8333_read_block(lm8333, LM8333_FIFO_READ, 117 LM8333_FIFO_TRANSFER_SIZE, dummy); 118 } 119 dev_err(&lm8333->client->dev, "Got error %02x\n", err); 120 } 121 122 if (status & LM8333_KEYPAD_IRQ) 123 lm8333_key_handler(lm8333); 124 125 return IRQ_HANDLED; 126} 127 128static int lm8333_probe(struct i2c_client *client) 129{ 130 const struct lm8333_platform_data *pdata = 131 dev_get_platdata(&client->dev); 132 struct lm8333 *lm8333; 133 struct input_dev *input; 134 int err, active_time; 135 136 if (!pdata) 137 return -EINVAL; 138 139 active_time = pdata->active_time ?: 500; 140 if (active_time / 3 <= pdata->debounce_time / 3) { 141 dev_err(&client->dev, "Active time not big enough!\n"); 142 return -EINVAL; 143 } 144 145 lm8333 = devm_kzalloc(&client->dev, sizeof(*lm8333), GFP_KERNEL); 146 if (!lm8333) 147 return -ENOMEM; 148 149 input = devm_input_allocate_device(&client->dev); 150 if (!input) 151 return -ENOMEM; 152 153 lm8333->client = client; 154 lm8333->input = input; 155 156 input->name = client->name; 157 input->id.bustype = BUS_I2C; 158 159 input_set_capability(input, EV_MSC, MSC_SCAN); 160 161 err = matrix_keypad_build_keymap(pdata->matrix_data, NULL, 162 LM8333_NUM_ROWS, LM8333_NUM_COLS, 163 lm8333->keycodes, input); 164 if (err) 165 return err; 166 167 if (pdata->debounce_time) { 168 err = lm8333_write8(lm8333, LM8333_DEBOUNCE, 169 pdata->debounce_time / 3); 170 if (err) 171 dev_warn(&client->dev, "Unable to set debounce time\n"); 172 } 173 174 if (pdata->active_time) { 175 err = lm8333_write8(lm8333, LM8333_ACTIVE, 176 pdata->active_time / 3); 177 if (err) 178 dev_warn(&client->dev, "Unable to set active time\n"); 179 } 180 181 err = devm_request_threaded_irq(&client->dev, client->irq, 182 NULL, lm8333_irq_thread, 183 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 184 "lm8333", lm8333); 185 if (err) 186 return err; 187 188 err = input_register_device(input); 189 if (err) 190 return err; 191 192 i2c_set_clientdata(client, lm8333); 193 return 0; 194} 195 196static const struct i2c_device_id lm8333_id[] = { 197 { "lm8333", 0 }, 198 { } 199}; 200MODULE_DEVICE_TABLE(i2c, lm8333_id); 201 202static struct i2c_driver lm8333_driver = { 203 .driver = { 204 .name = "lm8333", 205 }, 206 .probe = lm8333_probe, 207 .id_table = lm8333_id, 208}; 209module_i2c_driver(lm8333_driver); 210 211MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>"); 212MODULE_DESCRIPTION("LM8333 keyboard driver"); 213MODULE_LICENSE("GPL v2"); 214