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 33 struct 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 42 int 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 53 int 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 64 int 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 76 static 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 } 101 102 static 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 } 127 128 static 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 = kzalloc(sizeof(*lm8333), GFP_KERNEL); 146 input = input_allocate_device(); 147 if (!lm8333 || !input) { 148 err = -ENOMEM; 149 goto free_mem; 150 } 151 152 lm8333->client = client; 153 lm8333->input = input; 154 155 input->name = client->name; 156 input->dev.parent = &client->dev; 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 goto free_mem; 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 = request_threaded_irq(client->irq, NULL, lm8333_irq_thread, 182 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 183 "lm8333", lm8333); 184 if (err) 185 goto free_mem; 186 187 err = input_register_device(input); 188 if (err) 189 goto free_irq; 190 191 i2c_set_clientdata(client, lm8333); 192 return 0; 193 194 free_irq: 195 free_irq(client->irq, lm8333); 196 free_mem: 197 input_free_device(input); 198 kfree(lm8333); 199 return err; 200 } 201 202 static void lm8333_remove(struct i2c_client *client) 203 { 204 struct lm8333 *lm8333 = i2c_get_clientdata(client); 205 206 free_irq(client->irq, lm8333); 207 input_unregister_device(lm8333->input); 208 kfree(lm8333); 209 } 210 211 static const struct i2c_device_id lm8333_id[] = { 212 { "lm8333", 0 }, 213 { } 214 }; 215 MODULE_DEVICE_TABLE(i2c, lm8333_id); 216 217 static struct i2c_driver lm8333_driver = { 218 .driver = { 219 .name = "lm8333", 220 }, 221 .probe_new = lm8333_probe, 222 .remove = lm8333_remove, 223 .id_table = lm8333_id, 224 }; 225 module_i2c_driver(lm8333_driver); 226 227 MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>"); 228 MODULE_DESCRIPTION("LM8333 keyboard driver"); 229 MODULE_LICENSE("GPL v2"); 230