drivers/input/keyboard/lpc32xx-keys.c

   1 /*
   2  * NXP LPC32xx SoC Key Scan Interface
   3  *
   4  * Authors:
   5  *    Kevin Wells <kevin.wells@nxp.com>
   6  *    Roland Stigge <stigge@antcom.de>
   7  *
   8  * Copyright (C) 2010 NXP Semiconductors
   9  * Copyright (C) 2012 Roland Stigge
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  *
  22  * This controller supports square key matrices from 1x1 up to 8x8
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/slab.h>
  28 #include <linux/irq.h>
  29 #include <linux/pm.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/input.h>
  32 #include <linux/clk.h>
  33 #include <linux/io.h>
  34 #include <linux/of.h>
  35 #include <linux/input/matrix_keypad.h>
  36
  37 #define DRV_NAME                                "lpc32xx_keys"
  38
  39 /*
  40  * Key scanner register offsets
  41  */
  42 #define LPC32XX_KS_DEB(x)                       ((x) + 0x00)
  43 #define LPC32XX_KS_STATE_COND(x)                ((x) + 0x04)
  44 #define LPC32XX_KS_IRQ(x)                       ((x) + 0x08)
  45 #define LPC32XX_KS_SCAN_CTL(x)                  ((x) + 0x0C)
  46 #define LPC32XX_KS_FAST_TST(x)                  ((x) + 0x10)
  47 #define LPC32XX_KS_MATRIX_DIM(x)                ((x) + 0x14) /* 1..8 */
  48 #define LPC32XX_KS_DATA(x, y)                   ((x) + 0x40 + ((y) << 2))
  49
  50 #define LPC32XX_KSCAN_DEB_NUM_DEB_PASS(n)       ((n) & 0xFF)
  51
  52 #define LPC32XX_KSCAN_SCOND_IN_IDLE             0x0
  53 #define LPC32XX_KSCAN_SCOND_IN_SCANONCE         0x1
  54 #define LPC32XX_KSCAN_SCOND_IN_IRQGEN           0x2
  55 #define LPC32XX_KSCAN_SCOND_IN_SCAN_MATRIX      0x3
  56
  57 #define LPC32XX_KSCAN_IRQ_PENDING_CLR           0x1
  58
  59 #define LPC32XX_KSCAN_SCTRL_SCAN_DELAY(n)       ((n) & 0xFF)
  60
  61 #define LPC32XX_KSCAN_FTST_FORCESCANONCE        0x1
  62 #define LPC32XX_KSCAN_FTST_USE32K_CLK           0x2
  63
  64 #define LPC32XX_KSCAN_MSEL_SELECT(n)            ((n) & 0xF)
  65
  66 struct lpc32xx_kscan_drv {
  67         struct input_dev *input;
  68         struct clk *clk;
  69         void __iomem *kscan_base;
  70         unsigned int irq;
  71
  72         u32 matrix_sz;          /* Size of matrix in XxY, ie. 3 = 3x3 */
  73         u32 deb_clks;           /* Debounce clocks (based on 32KHz clock) */
  74         u32 scan_delay;         /* Scan delay (based on 32KHz clock) */
  75
  76         unsigned short *keymap; /* Pointer to key map for the scan matrix */
  77         unsigned int row_shift;
  78
  79         u8 lastkeystates[8];
  80 };
  81
  82 static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)
  83 {
  84         struct input_dev *input = kscandat->input;
  85         unsigned row, changed, scancode, keycode;
  86         u8 key;
  87
  88         key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, col));
  89         changed = key ^ kscandat->lastkeystates[col];
  90         kscandat->lastkeystates[col] = key;
  91
  92         for (row = 0; changed; row++, changed >>= 1) {
  93                 if (changed & 1) {
  94                         /* Key state changed, signal an event */
  95                         scancode = MATRIX_SCAN_CODE(row, col,
  96                                                     kscandat->row_shift);
  97                         keycode = kscandat->keymap[scancode];
  98                         input_event(input, EV_MSC, MSC_SCAN, scancode);
  99                         input_report_key(input, keycode, key & (1 << row));
 100                 }
 101         }
 102 }
 103
 104 static irqreturn_t lpc32xx_kscan_irq(int irq, void *dev_id)
 105 {
 106         struct lpc32xx_kscan_drv *kscandat = dev_id;
 107         int i;
 108
 109         for (i = 0; i < kscandat->matrix_sz; i++)
 110                 lpc32xx_mod_states(kscandat, i);
 111
 112         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 113
 114         input_sync(kscandat->input);
 115
 116         return IRQ_HANDLED;
 117 }
 118
 119 static int lpc32xx_kscan_open(struct input_dev *dev)
 120 {
 121         struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
 122         int error;
 123
 124         error = clk_prepare_enable(kscandat->clk);
 125         if (error)
 126                 return error;
 127
 128         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 129
 130         return 0;
 131 }
 132
 133 static void lpc32xx_kscan_close(struct input_dev *dev)
 134 {
 135         struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
 136
 137         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 138         clk_disable_unprepare(kscandat->clk);
 139 }
 140
 141 static int lpc32xx_parse_dt(struct device *dev,
 142                                       struct lpc32xx_kscan_drv *kscandat)
 143 {
 144         struct device_node *np = dev->of_node;
 145         u32 rows = 0, columns = 0;
 146         int err;
 147
 148         err = matrix_keypad_parse_of_params(dev, &rows, &columns);
 149         if (err)
 150                 return err;
 151         if (rows != columns) {
 152                 dev_err(dev, "rows and columns must be equal!\n");
 153                 return -EINVAL;
 154         }
 155
 156         kscandat->matrix_sz = rows;
 157         kscandat->row_shift = get_count_order(columns);
 158
 159         of_property_read_u32(np, "nxp,debounce-delay-ms", &kscandat->deb_clks);
 160         of_property_read_u32(np, "nxp,scan-delay-ms", &kscandat->scan_delay);
 161         if (!kscandat->deb_clks || !kscandat->scan_delay) {
 162                 dev_err(dev, "debounce or scan delay not specified\n");
 163                 return -EINVAL;
 164         }
 165
 166         return 0;
 167 }
 168
 169 static int lpc32xx_kscan_probe(struct platform_device *pdev)
 170 {
 171         struct lpc32xx_kscan_drv *kscandat;
 172         struct input_dev *input;
 173         struct resource *res;
 174         size_t keymap_size;
 175         int error;
 176         int irq;
 177
 178         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 179         if (!res) {
 180                 dev_err(&pdev->dev, "failed to get platform I/O memory\n");
 181                 return -EINVAL;
 182         }
 183
 184         irq = platform_get_irq(pdev, 0);
 185         if (irq < 0 || irq >= NR_IRQS) {
 186                 dev_err(&pdev->dev, "failed to get platform irq\n");
 187                 return -EINVAL;
 188         }
 189
 190         kscandat = devm_kzalloc(&pdev->dev, sizeof(*kscandat),
 191                                 GFP_KERNEL);
 192         if (!kscandat)
 193                 return -ENOMEM;
 194
 195         error = lpc32xx_parse_dt(&pdev->dev, kscandat);
 196         if (error) {
 197                 dev_err(&pdev->dev, "failed to parse device tree\n");
 198                 return error;
 199         }
 200
 201         keymap_size = sizeof(kscandat->keymap[0]) *
 202                                 (kscandat->matrix_sz << kscandat->row_shift);
 203         kscandat->keymap = devm_kzalloc(&pdev->dev, keymap_size, GFP_KERNEL);
 204         if (!kscandat->keymap)
 205                 return -ENOMEM;
 206
 207         kscandat->input = input = devm_input_allocate_device(&pdev->dev);
 208         if (!input) {
 209                 dev_err(&pdev->dev, "failed to allocate input device\n");
 210                 return -ENOMEM;
 211         }
 212
 213         /* Setup key input */
 214         input->name             = pdev->name;
 215         input->phys             = "lpc32xx/input0";
 216         input->id.vendor        = 0x0001;
 217         input->id.product       = 0x0001;
 218         input->id.version       = 0x0100;
 219         input->open             = lpc32xx_kscan_open;
 220         input->close            = lpc32xx_kscan_close;
 221         input->dev.parent       = &pdev->dev;
 222
 223         input_set_capability(input, EV_MSC, MSC_SCAN);
 224
 225         error = matrix_keypad_build_keymap(NULL, NULL,
 226                                            kscandat->matrix_sz,
 227                                            kscandat->matrix_sz,
 228                                            kscandat->keymap, kscandat->input);
 229         if (error) {
 230                 dev_err(&pdev->dev, "failed to build keymap\n");
 231                 return error;
 232         }
 233
 234         input_set_drvdata(kscandat->input, kscandat);
 235
 236         kscandat->kscan_base = devm_ioremap_resource(&pdev->dev, res);
 237         if (IS_ERR(kscandat->kscan_base))
 238                 return PTR_ERR(kscandat->kscan_base);
 239
 240         /* Get the key scanner clock */
 241         kscandat->clk = devm_clk_get(&pdev->dev, NULL);
 242         if (IS_ERR(kscandat->clk)) {
 243                 dev_err(&pdev->dev, "failed to get clock\n");
 244                 return PTR_ERR(kscandat->clk);
 245         }
 246
 247         /* Configure the key scanner */
 248         error = clk_prepare_enable(kscandat->clk);
 249         if (error)
 250                 return error;
 251
 252         writel(kscandat->deb_clks, LPC32XX_KS_DEB(kscandat->kscan_base));
 253         writel(kscandat->scan_delay, LPC32XX_KS_SCAN_CTL(kscandat->kscan_base));
 254         writel(LPC32XX_KSCAN_FTST_USE32K_CLK,
 255                LPC32XX_KS_FAST_TST(kscandat->kscan_base));
 256         writel(kscandat->matrix_sz,
 257                LPC32XX_KS_MATRIX_DIM(kscandat->kscan_base));
 258         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 259         clk_disable_unprepare(kscandat->clk);
 260
 261         error = devm_request_irq(&pdev->dev, irq, lpc32xx_kscan_irq, 0,
 262                                  pdev->name, kscandat);
 263         if (error) {
 264                 dev_err(&pdev->dev, "failed to request irq\n");
 265                 return error;
 266         }
 267
 268         error = input_register_device(kscandat->input);
 269         if (error) {
 270                 dev_err(&pdev->dev, "failed to register input device\n");
 271                 return error;
 272         }
 273
 274         platform_set_drvdata(pdev, kscandat);
 275
 276         return 0;
 277 }
 278
 279 #ifdef CONFIG_PM_SLEEP
 280 static int lpc32xx_kscan_suspend(struct device *dev)
 281 {
 282         struct platform_device *pdev = to_platform_device(dev);
 283         struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 284         struct input_dev *input = kscandat->input;
 285
 286         mutex_lock(&input->mutex);
 287
 288         if (input->users) {
 289                 /* Clear IRQ and disable clock */
 290                 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 291                 clk_disable_unprepare(kscandat->clk);
 292         }
 293
 294         mutex_unlock(&input->mutex);
 295         return 0;
 296 }
 297
 298 static int lpc32xx_kscan_resume(struct device *dev)
 299 {
 300         struct platform_device *pdev = to_platform_device(dev);
 301         struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 302         struct input_dev *input = kscandat->input;
 303         int retval = 0;
 304
 305         mutex_lock(&input->mutex);
 306
 307         if (input->users) {
 308                 /* Enable clock and clear IRQ */
 309                 retval = clk_prepare_enable(kscandat->clk);
 310                 if (retval == 0)
 311                         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 312         }
 313
 314         mutex_unlock(&input->mutex);
 315         return retval;
 316 }
 317 #endif
 318
 319 static SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,
 320                          lpc32xx_kscan_resume);
 321
 322 static const struct of_device_id lpc32xx_kscan_match[] = {
 323         { .compatible = "nxp,lpc3220-key" },
 324         {},
 325 };
 326 MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);
 327
 328 static struct platform_driver lpc32xx_kscan_driver = {
 329         .probe          = lpc32xx_kscan_probe,
 330         .driver         = {
 331                 .name   = DRV_NAME,
 332                 .pm     = &lpc32xx_kscan_pm_ops,
 333                 .of_match_table = lpc32xx_kscan_match,
 334         }
 335 };
 336
 337 module_platform_driver(lpc32xx_kscan_driver);
 338
 339 MODULE_LICENSE("GPL");
 340 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
 341 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
 342 MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");