1 /* 2 * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2, as 6 * published by the Free Software Foundation. 7 */ 8 9 #include <linux/input/matrix_keypad.h> 10 #include <linux/platform_device.h> 11 #include <linux/interrupt.h> 12 #include <linux/io.h> 13 #include <linux/delay.h> 14 #include <linux/input.h> 15 #include <linux/slab.h> 16 #include <linux/clk.h> 17 #include <linux/module.h> 18 #include <linux/of.h> 19 20 #define KEYPAD_SCAN_MODE 0x00 21 #define KEYPAD_CNTL 0x04 22 #define KEYPAD_INT 0x08 23 #define KEYPAD_INTMSK 0x0C 24 25 #define KEYPAD_DATA 0x10 26 #define KEYPAD_GPIO 0x30 27 28 #define KEYPAD_UNKNOWN_INT 0x40 29 #define KEYPAD_UNKNOWN_INT_STS 0x44 30 31 #define KEYPAD_BITMASK_COLS 11 32 #define KEYPAD_BITMASK_ROWS 8 33 34 struct nspire_keypad { 35 void __iomem *reg_base; 36 u32 int_mask; 37 38 struct input_dev *input; 39 struct clk *clk; 40 41 struct matrix_keymap_data *keymap; 42 int row_shift; 43 44 /* Maximum delay estimated assuming 33MHz APB */ 45 u32 scan_interval; /* In microseconds (~2000us max) */ 46 u32 row_delay; /* In microseconds (~500us max) */ 47 48 u16 state[KEYPAD_BITMASK_ROWS]; 49 50 bool active_low; 51 }; 52 53 static irqreturn_t nspire_keypad_irq(int irq, void *dev_id) 54 { 55 struct nspire_keypad *keypad = dev_id; 56 struct input_dev *input = keypad->input; 57 unsigned short *keymap = input->keycode; 58 unsigned int code; 59 int row, col; 60 u32 int_sts; 61 u16 state[8]; 62 u16 bits, changed; 63 64 int_sts = readl(keypad->reg_base + KEYPAD_INT) & keypad->int_mask; 65 if (!int_sts) 66 return IRQ_NONE; 67 68 memcpy_fromio(state, keypad->reg_base + KEYPAD_DATA, sizeof(state)); 69 70 for (row = 0; row < KEYPAD_BITMASK_ROWS; row++) { 71 bits = state[row]; 72 if (keypad->active_low) 73 bits = ~bits; 74 75 changed = bits ^ keypad->state[row]; 76 if (!changed) 77 continue; 78 79 keypad->state[row] = bits; 80 81 for (col = 0; col < KEYPAD_BITMASK_COLS; col++) { 82 if (!(changed & (1U << col))) 83 continue; 84 85 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift); 86 input_event(input, EV_MSC, MSC_SCAN, code); 87 input_report_key(input, keymap[code], 88 bits & (1U << col)); 89 } 90 } 91 92 input_sync(input); 93 94 writel(0x3, keypad->reg_base + KEYPAD_INT); 95 96 return IRQ_HANDLED; 97 } 98 99 static int nspire_keypad_chip_init(struct nspire_keypad *keypad) 100 { 101 unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles; 102 103 cycles_per_us = (clk_get_rate(keypad->clk) / 1000000); 104 if (cycles_per_us == 0) 105 cycles_per_us = 1; 106 107 delay_cycles = cycles_per_us * keypad->scan_interval; 108 WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */ 109 delay_cycles &= 0xffff; 110 111 row_delay_cycles = cycles_per_us * keypad->row_delay; 112 WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */ 113 row_delay_cycles &= 0x3fff; 114 115 val |= 3 << 0; /* Set scan mode to 3 (continuous scan) */ 116 val |= row_delay_cycles << 2; /* Delay between scanning each row */ 117 val |= delay_cycles << 16; /* Delay between scans */ 118 writel(val, keypad->reg_base + KEYPAD_SCAN_MODE); 119 120 val = (KEYPAD_BITMASK_ROWS & 0xff) | (KEYPAD_BITMASK_COLS & 0xff)<<8; 121 writel(val, keypad->reg_base + KEYPAD_CNTL); 122 123 /* Enable interrupts */ 124 keypad->int_mask = 1 << 1; 125 writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK); 126 127 /* Disable GPIO interrupts to prevent hanging on touchpad */ 128 /* Possibly used to detect touchpad events */ 129 writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT); 130 /* Acknowledge existing interrupts */ 131 writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS); 132 133 return 0; 134 } 135 136 static int nspire_keypad_open(struct input_dev *input) 137 { 138 struct nspire_keypad *keypad = input_get_drvdata(input); 139 int error; 140 141 error = clk_prepare_enable(keypad->clk); 142 if (error) 143 return error; 144 145 error = nspire_keypad_chip_init(keypad); 146 if (error) { 147 clk_disable_unprepare(keypad->clk); 148 return error; 149 } 150 151 return 0; 152 } 153 154 static void nspire_keypad_close(struct input_dev *input) 155 { 156 struct nspire_keypad *keypad = input_get_drvdata(input); 157 158 clk_disable_unprepare(keypad->clk); 159 } 160 161 static int nspire_keypad_probe(struct platform_device *pdev) 162 { 163 const struct device_node *of_node = pdev->dev.of_node; 164 struct nspire_keypad *keypad; 165 struct input_dev *input; 166 struct resource *res; 167 int irq; 168 int error; 169 170 irq = platform_get_irq(pdev, 0); 171 if (irq < 0) { 172 dev_err(&pdev->dev, "failed to get keypad irq\n"); 173 return -EINVAL; 174 } 175 176 keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad), 177 GFP_KERNEL); 178 if (!keypad) { 179 dev_err(&pdev->dev, "failed to allocate keypad memory\n"); 180 return -ENOMEM; 181 } 182 183 keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS); 184 185 error = of_property_read_u32(of_node, "scan-interval", 186 &keypad->scan_interval); 187 if (error) { 188 dev_err(&pdev->dev, "failed to get scan-interval\n"); 189 return error; 190 } 191 192 error = of_property_read_u32(of_node, "row-delay", 193 &keypad->row_delay); 194 if (error) { 195 dev_err(&pdev->dev, "failed to get row-delay\n"); 196 return error; 197 } 198 199 keypad->active_low = of_property_read_bool(of_node, "active-low"); 200 201 keypad->clk = devm_clk_get(&pdev->dev, NULL); 202 if (IS_ERR(keypad->clk)) { 203 dev_err(&pdev->dev, "unable to get clock\n"); 204 return PTR_ERR(keypad->clk); 205 } 206 207 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 208 keypad->reg_base = devm_ioremap_resource(&pdev->dev, res); 209 if (IS_ERR(keypad->reg_base)) 210 return PTR_ERR(keypad->reg_base); 211 212 keypad->input = input = devm_input_allocate_device(&pdev->dev); 213 if (!input) { 214 dev_err(&pdev->dev, "failed to allocate input device\n"); 215 return -ENOMEM; 216 } 217 218 input_set_drvdata(input, keypad); 219 220 input->id.bustype = BUS_HOST; 221 input->name = "nspire-keypad"; 222 input->open = nspire_keypad_open; 223 input->close = nspire_keypad_close; 224 225 __set_bit(EV_KEY, input->evbit); 226 __set_bit(EV_REP, input->evbit); 227 input_set_capability(input, EV_MSC, MSC_SCAN); 228 229 error = matrix_keypad_build_keymap(NULL, NULL, 230 KEYPAD_BITMASK_ROWS, 231 KEYPAD_BITMASK_COLS, 232 NULL, input); 233 if (error) { 234 dev_err(&pdev->dev, "building keymap failed\n"); 235 return error; 236 } 237 238 error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0, 239 "nspire_keypad", keypad); 240 if (error) { 241 dev_err(&pdev->dev, "allocate irq %d failed\n", irq); 242 return error; 243 } 244 245 error = input_register_device(input); 246 if (error) { 247 dev_err(&pdev->dev, 248 "unable to register input device: %d\n", error); 249 return error; 250 } 251 252 platform_set_drvdata(pdev, keypad); 253 254 dev_dbg(&pdev->dev, 255 "TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n", 256 res, keypad->row_delay, keypad->scan_interval, 257 keypad->active_low ? ", active_low" : ""); 258 259 return 0; 260 } 261 262 static const struct of_device_id nspire_keypad_dt_match[] = { 263 { .compatible = "ti,nspire-keypad" }, 264 { }, 265 }; 266 MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match); 267 268 static struct platform_driver nspire_keypad_driver = { 269 .driver = { 270 .name = "nspire-keypad", 271 .of_match_table = nspire_keypad_dt_match, 272 }, 273 .probe = nspire_keypad_probe, 274 }; 275 276 module_platform_driver(nspire_keypad_driver); 277 278 MODULE_LICENSE("GPL"); 279 MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver"); 280