Version:  2.0.40 2.2.26 2.4.37 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2

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         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");
343 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us