1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * STMicroelectronics Key Scanning driver 4 * 5 * Copyright (c) 2014 STMicroelectonics Ltd. 6 * Author: Stuart Menefy <stuart.menefy@st.com> 7 * 8 * Based on sh_keysc.c, copyright 2008 Magnus Damm 9 */ 10 11 #include <linux/clk.h> 12 #include <linux/input.h> 13 #include <linux/input/matrix_keypad.h> 14 #include <linux/io.h> 15 #include <linux/interrupt.h> 16 #include <linux/module.h> 17 #include <linux/of.h> 18 #include <linux/platform_device.h> 19 20 #define ST_KEYSCAN_MAXKEYS 16 21 22 #define KEYSCAN_CONFIG_OFF 0x0 23 #define KEYSCAN_CONFIG_ENABLE 0x1 24 #define KEYSCAN_DEBOUNCE_TIME_OFF 0x4 25 #define KEYSCAN_MATRIX_STATE_OFF 0x8 26 #define KEYSCAN_MATRIX_DIM_OFF 0xc 27 #define KEYSCAN_MATRIX_DIM_X_SHIFT 0x0 28 #define KEYSCAN_MATRIX_DIM_Y_SHIFT 0x2 29 30 struct st_keyscan { 31 void __iomem *base; 32 int irq; 33 struct clk *clk; 34 struct input_dev *input_dev; 35 unsigned long last_state; 36 unsigned int n_rows; 37 unsigned int n_cols; 38 unsigned int debounce_us; 39 }; 40 41 static irqreturn_t keyscan_isr(int irq, void *dev_id) 42 { 43 struct st_keyscan *keypad = dev_id; 44 unsigned short *keycode = keypad->input_dev->keycode; 45 unsigned long state, change; 46 int bit_nr; 47 48 state = readl(keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff; 49 change = keypad->last_state ^ state; 50 keypad->last_state = state; 51 52 for_each_set_bit(bit_nr, &change, BITS_PER_LONG) 53 input_report_key(keypad->input_dev, 54 keycode[bit_nr], state & BIT(bit_nr)); 55 56 input_sync(keypad->input_dev); 57 58 return IRQ_HANDLED; 59 } 60 61 static int keyscan_start(struct st_keyscan *keypad) 62 { 63 int error; 64 65 error = clk_enable(keypad->clk); 66 if (error) 67 return error; 68 69 writel(keypad->debounce_us * (clk_get_rate(keypad->clk) / 1000000), 70 keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF); 71 72 writel(((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) | 73 ((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT), 74 keypad->base + KEYSCAN_MATRIX_DIM_OFF); 75 76 writel(KEYSCAN_CONFIG_ENABLE, keypad->base + KEYSCAN_CONFIG_OFF); 77 78 return 0; 79 } 80 81 static void keyscan_stop(struct st_keyscan *keypad) 82 { 83 writel(0, keypad->base + KEYSCAN_CONFIG_OFF); 84 85 clk_disable(keypad->clk); 86 } 87 88 static int keyscan_open(struct input_dev *dev) 89 { 90 struct st_keyscan *keypad = input_get_drvdata(dev); 91 92 return keyscan_start(keypad); 93 } 94 95 static void keyscan_close(struct input_dev *dev) 96 { 97 struct st_keyscan *keypad = input_get_drvdata(dev); 98 99 keyscan_stop(keypad); 100 } 101 102 static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data) 103 { 104 struct device *dev = keypad_data->input_dev->dev.parent; 105 struct device_node *np = dev->of_node; 106 int error; 107 108 error = matrix_keypad_parse_properties(dev, &keypad_data->n_rows, 109 &keypad_data->n_cols); 110 if (error) { 111 dev_err(dev, "failed to parse keypad params\n"); 112 return error; 113 } 114 115 of_property_read_u32(np, "st,debounce-us", &keypad_data->debounce_us); 116 117 dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n", 118 keypad_data->n_rows, keypad_data->n_cols, 119 keypad_data->debounce_us); 120 121 return 0; 122 } 123 124 static int keyscan_probe(struct platform_device *pdev) 125 { 126 struct st_keyscan *keypad_data; 127 struct input_dev *input_dev; 128 int error; 129 130 if (!pdev->dev.of_node) { 131 dev_err(&pdev->dev, "no DT data present\n"); 132 return -EINVAL; 133 } 134 135 keypad_data = devm_kzalloc(&pdev->dev, sizeof(*keypad_data), 136 GFP_KERNEL); 137 if (!keypad_data) 138 return -ENOMEM; 139 140 input_dev = devm_input_allocate_device(&pdev->dev); 141 if (!input_dev) { 142 dev_err(&pdev->dev, "failed to allocate the input device\n"); 143 return -ENOMEM; 144 } 145 146 input_dev->name = pdev->name; 147 input_dev->phys = "keyscan-keys/input0"; 148 input_dev->dev.parent = &pdev->dev; 149 input_dev->open = keyscan_open; 150 input_dev->close = keyscan_close; 151 152 input_dev->id.bustype = BUS_HOST; 153 154 keypad_data->input_dev = input_dev; 155 156 error = keypad_matrix_key_parse_dt(keypad_data); 157 if (error) 158 return error; 159 160 error = matrix_keypad_build_keymap(NULL, NULL, 161 keypad_data->n_rows, 162 keypad_data->n_cols, 163 NULL, input_dev); 164 if (error) { 165 dev_err(&pdev->dev, "failed to build keymap\n"); 166 return error; 167 } 168 169 input_set_drvdata(input_dev, keypad_data); 170 171 keypad_data->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); 172 if (IS_ERR(keypad_data->base)) 173 return PTR_ERR(keypad_data->base); 174 175 keypad_data->clk = devm_clk_get(&pdev->dev, NULL); 176 if (IS_ERR(keypad_data->clk)) { 177 dev_err(&pdev->dev, "cannot get clock\n"); 178 return PTR_ERR(keypad_data->clk); 179 } 180 181 error = clk_enable(keypad_data->clk); 182 if (error) { 183 dev_err(&pdev->dev, "failed to enable clock\n"); 184 return error; 185 } 186 187 keyscan_stop(keypad_data); 188 189 keypad_data->irq = platform_get_irq(pdev, 0); 190 if (keypad_data->irq < 0) 191 return -EINVAL; 192 193 error = devm_request_irq(&pdev->dev, keypad_data->irq, keyscan_isr, 0, 194 pdev->name, keypad_data); 195 if (error) { 196 dev_err(&pdev->dev, "failed to request IRQ\n"); 197 return error; 198 } 199 200 error = input_register_device(input_dev); 201 if (error) { 202 dev_err(&pdev->dev, "failed to register input device\n"); 203 return error; 204 } 205 206 platform_set_drvdata(pdev, keypad_data); 207 208 device_set_wakeup_capable(&pdev->dev, 1); 209 210 return 0; 211 } 212 213 static int keyscan_suspend(struct device *dev) 214 { 215 struct platform_device *pdev = to_platform_device(dev); 216 struct st_keyscan *keypad = platform_get_drvdata(pdev); 217 struct input_dev *input = keypad->input_dev; 218 219 mutex_lock(&input->mutex); 220 221 if (device_may_wakeup(dev)) 222 enable_irq_wake(keypad->irq); 223 else if (input_device_enabled(input)) 224 keyscan_stop(keypad); 225 226 mutex_unlock(&input->mutex); 227 return 0; 228 } 229 230 static int keyscan_resume(struct device *dev) 231 { 232 struct platform_device *pdev = to_platform_device(dev); 233 struct st_keyscan *keypad = platform_get_drvdata(pdev); 234 struct input_dev *input = keypad->input_dev; 235 int retval = 0; 236 237 mutex_lock(&input->mutex); 238 239 if (device_may_wakeup(dev)) 240 disable_irq_wake(keypad->irq); 241 else if (input_device_enabled(input)) 242 retval = keyscan_start(keypad); 243 244 mutex_unlock(&input->mutex); 245 return retval; 246 } 247 248 static DEFINE_SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, 249 keyscan_suspend, keyscan_resume); 250 251 static const struct of_device_id keyscan_of_match[] = { 252 { .compatible = "st,sti-keyscan" }, 253 { }, 254 }; 255 MODULE_DEVICE_TABLE(of, keyscan_of_match); 256 257 static struct platform_driver keyscan_device_driver = { 258 .probe = keyscan_probe, 259 .driver = { 260 .name = "st-keyscan", 261 .pm = pm_sleep_ptr(&keyscan_dev_pm_ops), 262 .of_match_table = of_match_ptr(keyscan_of_match), 263 } 264 }; 265 266 module_platform_driver(keyscan_device_driver); 267 268 MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>"); 269 MODULE_DESCRIPTION("STMicroelectronics keyscan device driver"); 270 MODULE_LICENSE("GPL"); 271