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Linux/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         struct resource *iores;
 70         void __iomem *kscan_base;
 71         unsigned int irq;
 72 
 73         u32 matrix_sz;          /* Size of matrix in XxY, ie. 3 = 3x3 */
 74         u32 deb_clks;           /* Debounce clocks (based on 32KHz clock) */
 75         u32 scan_delay;         /* Scan delay (based on 32KHz clock) */
 76 
 77         unsigned short *keymap; /* Pointer to key map for the scan matrix */
 78         unsigned int row_shift;
 79 
 80         u8 lastkeystates[8];
 81 };
 82 
 83 static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)
 84 {
 85         struct input_dev *input = kscandat->input;
 86         unsigned row, changed, scancode, keycode;
 87         u8 key;
 88 
 89         key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, col));
 90         changed = key ^ kscandat->lastkeystates[col];
 91         kscandat->lastkeystates[col] = key;
 92 
 93         for (row = 0; changed; row++, changed >>= 1) {
 94                 if (changed & 1) {
 95                         /* Key state changed, signal an event */
 96                         scancode = MATRIX_SCAN_CODE(row, col,
 97                                                     kscandat->row_shift);
 98                         keycode = kscandat->keymap[scancode];
 99                         input_event(input, EV_MSC, MSC_SCAN, scancode);
100                         input_report_key(input, keycode, key & (1 << row));
101                 }
102         }
103 }
104 
105 static irqreturn_t lpc32xx_kscan_irq(int irq, void *dev_id)
106 {
107         struct lpc32xx_kscan_drv *kscandat = dev_id;
108         int i;
109 
110         for (i = 0; i < kscandat->matrix_sz; i++)
111                 lpc32xx_mod_states(kscandat, i);
112 
113         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
114 
115         input_sync(kscandat->input);
116 
117         return IRQ_HANDLED;
118 }
119 
120 static int lpc32xx_kscan_open(struct input_dev *dev)
121 {
122         struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
123         int error;
124 
125         error = clk_prepare_enable(kscandat->clk);
126         if (error)
127                 return error;
128 
129         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
130 
131         return 0;
132 }
133 
134 static void lpc32xx_kscan_close(struct input_dev *dev)
135 {
136         struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
137 
138         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
139         clk_disable_unprepare(kscandat->clk);
140 }
141 
142 static int lpc32xx_parse_dt(struct device *dev,
143                                       struct lpc32xx_kscan_drv *kscandat)
144 {
145         struct device_node *np = dev->of_node;
146         u32 rows = 0, columns = 0;
147         int err;
148 
149         err = matrix_keypad_parse_of_params(dev, &rows, &columns);
150         if (err)
151                 return err;
152         if (rows != columns) {
153                 dev_err(dev, "rows and columns must be equal!\n");
154                 return -EINVAL;
155         }
156 
157         kscandat->matrix_sz = rows;
158         kscandat->row_shift = get_count_order(columns);
159 
160         of_property_read_u32(np, "nxp,debounce-delay-ms", &kscandat->deb_clks);
161         of_property_read_u32(np, "nxp,scan-delay-ms", &kscandat->scan_delay);
162         if (!kscandat->deb_clks || !kscandat->scan_delay) {
163                 dev_err(dev, "debounce or scan delay not specified\n");
164                 return -EINVAL;
165         }
166 
167         return 0;
168 }
169 
170 static int lpc32xx_kscan_probe(struct platform_device *pdev)
171 {
172         struct lpc32xx_kscan_drv *kscandat;
173         struct input_dev *input;
174         struct resource *res;
175         size_t keymap_size;
176         int error;
177         int irq;
178 
179         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
180         if (!res) {
181                 dev_err(&pdev->dev, "failed to get platform I/O memory\n");
182                 return -EINVAL;
183         }
184 
185         irq = platform_get_irq(pdev, 0);
186         if (irq < 0 || irq >= NR_IRQS) {
187                 dev_err(&pdev->dev, "failed to get platform irq\n");
188                 return -EINVAL;
189         }
190 
191         kscandat = kzalloc(sizeof(struct lpc32xx_kscan_drv), GFP_KERNEL);
192         if (!kscandat) {
193                 dev_err(&pdev->dev, "failed to allocate memory\n");
194                 return -ENOMEM;
195         }
196 
197         error = lpc32xx_parse_dt(&pdev->dev, kscandat);
198         if (error) {
199                 dev_err(&pdev->dev, "failed to parse device tree\n");
200                 goto err_free_mem;
201         }
202 
203         keymap_size = sizeof(kscandat->keymap[0]) *
204                                 (kscandat->matrix_sz << kscandat->row_shift);
205         kscandat->keymap = kzalloc(keymap_size, GFP_KERNEL);
206         if (!kscandat->keymap) {
207                 dev_err(&pdev->dev, "could not allocate memory for keymap\n");
208                 error = -ENOMEM;
209                 goto err_free_mem;
210         }
211 
212         kscandat->input = input = input_allocate_device();
213         if (!input) {
214                 dev_err(&pdev->dev, "failed to allocate input device\n");
215                 error = -ENOMEM;
216                 goto err_free_keymap;
217         }
218 
219         /* Setup key input */
220         input->name             = pdev->name;
221         input->phys             = "lpc32xx/input0";
222         input->id.vendor        = 0x0001;
223         input->id.product       = 0x0001;
224         input->id.version       = 0x0100;
225         input->open             = lpc32xx_kscan_open;
226         input->close            = lpc32xx_kscan_close;
227         input->dev.parent       = &pdev->dev;
228 
229         input_set_capability(input, EV_MSC, MSC_SCAN);
230 
231         error = matrix_keypad_build_keymap(NULL, NULL,
232                                            kscandat->matrix_sz,
233                                            kscandat->matrix_sz,
234                                            kscandat->keymap, kscandat->input);
235         if (error) {
236                 dev_err(&pdev->dev, "failed to build keymap\n");
237                 goto err_free_input;
238         }
239 
240         input_set_drvdata(kscandat->input, kscandat);
241 
242         kscandat->iores = request_mem_region(res->start, resource_size(res),
243                                              pdev->name);
244         if (!kscandat->iores) {
245                 dev_err(&pdev->dev, "failed to request I/O memory\n");
246                 error = -EBUSY;
247                 goto err_free_input;
248         }
249 
250         kscandat->kscan_base = ioremap(kscandat->iores->start,
251                                        resource_size(kscandat->iores));
252         if (!kscandat->kscan_base) {
253                 dev_err(&pdev->dev, "failed to remap I/O memory\n");
254                 error = -EBUSY;
255                 goto err_release_memregion;
256         }
257 
258         /* Get the key scanner clock */
259         kscandat->clk = clk_get(&pdev->dev, NULL);
260         if (IS_ERR(kscandat->clk)) {
261                 dev_err(&pdev->dev, "failed to get clock\n");
262                 error = PTR_ERR(kscandat->clk);
263                 goto err_unmap;
264         }
265 
266         /* Configure the key scanner */
267         error = clk_prepare_enable(kscandat->clk);
268         if (error)
269                 goto err_clk_put;
270 
271         writel(kscandat->deb_clks, LPC32XX_KS_DEB(kscandat->kscan_base));
272         writel(kscandat->scan_delay, LPC32XX_KS_SCAN_CTL(kscandat->kscan_base));
273         writel(LPC32XX_KSCAN_FTST_USE32K_CLK,
274                LPC32XX_KS_FAST_TST(kscandat->kscan_base));
275         writel(kscandat->matrix_sz,
276                LPC32XX_KS_MATRIX_DIM(kscandat->kscan_base));
277         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
278         clk_disable_unprepare(kscandat->clk);
279 
280         error = request_irq(irq, lpc32xx_kscan_irq, 0, pdev->name, kscandat);
281         if (error) {
282                 dev_err(&pdev->dev, "failed to request irq\n");
283                 goto err_clk_put;
284         }
285 
286         error = input_register_device(kscandat->input);
287         if (error) {
288                 dev_err(&pdev->dev, "failed to register input device\n");
289                 goto err_free_irq;
290         }
291 
292         platform_set_drvdata(pdev, kscandat);
293         return 0;
294 
295 err_free_irq:
296         free_irq(irq, kscandat);
297 err_clk_put:
298         clk_put(kscandat->clk);
299 err_unmap:
300         iounmap(kscandat->kscan_base);
301 err_release_memregion:
302         release_mem_region(kscandat->iores->start,
303                            resource_size(kscandat->iores));
304 err_free_input:
305         input_free_device(kscandat->input);
306 err_free_keymap:
307         kfree(kscandat->keymap);
308 err_free_mem:
309         kfree(kscandat);
310 
311         return error;
312 }
313 
314 static int lpc32xx_kscan_remove(struct platform_device *pdev)
315 {
316         struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
317 
318         free_irq(platform_get_irq(pdev, 0), kscandat);
319         clk_put(kscandat->clk);
320         iounmap(kscandat->kscan_base);
321         release_mem_region(kscandat->iores->start,
322                            resource_size(kscandat->iores));
323         input_unregister_device(kscandat->input);
324         kfree(kscandat->keymap);
325         kfree(kscandat);
326 
327         return 0;
328 }
329 
330 #ifdef CONFIG_PM_SLEEP
331 static int lpc32xx_kscan_suspend(struct device *dev)
332 {
333         struct platform_device *pdev = to_platform_device(dev);
334         struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
335         struct input_dev *input = kscandat->input;
336 
337         mutex_lock(&input->mutex);
338 
339         if (input->users) {
340                 /* Clear IRQ and disable clock */
341                 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
342                 clk_disable_unprepare(kscandat->clk);
343         }
344 
345         mutex_unlock(&input->mutex);
346         return 0;
347 }
348 
349 static int lpc32xx_kscan_resume(struct device *dev)
350 {
351         struct platform_device *pdev = to_platform_device(dev);
352         struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
353         struct input_dev *input = kscandat->input;
354         int retval = 0;
355 
356         mutex_lock(&input->mutex);
357 
358         if (input->users) {
359                 /* Enable clock and clear IRQ */
360                 retval = clk_prepare_enable(kscandat->clk);
361                 if (retval == 0)
362                         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
363         }
364 
365         mutex_unlock(&input->mutex);
366         return retval;
367 }
368 #endif
369 
370 static SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,
371                          lpc32xx_kscan_resume);
372 
373 static const struct of_device_id lpc32xx_kscan_match[] = {
374         { .compatible = "nxp,lpc3220-key" },
375         {},
376 };
377 MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);
378 
379 static struct platform_driver lpc32xx_kscan_driver = {
380         .probe          = lpc32xx_kscan_probe,
381         .remove         = lpc32xx_kscan_remove,
382         .driver         = {
383                 .name   = DRV_NAME,
384                 .owner  = THIS_MODULE,
385                 .pm     = &lpc32xx_kscan_pm_ops,
386                 .of_match_table = lpc32xx_kscan_match,
387         }
388 };
389 
390 module_platform_driver(lpc32xx_kscan_driver);
391 
392 MODULE_LICENSE("GPL");
393 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
394 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
395 MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");
396 

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