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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * NXP LPC32xx SoC Key Scan Interface
4 *
5 * Authors:
6 * Kevin Wells <kevin.wells@nxp.com>
7 * Roland Stigge <stigge@antcom.de>
8 *
9 * Copyright (C) 2010 NXP Semiconductors
10 * Copyright (C) 2012 Roland Stigge
11 *
12 * This controller supports square key matrices from 1x1 up to 8x8
13 */
14
15#include <linux/module.h>
16#include <linux/interrupt.h>
17#include <linux/slab.h>
18#include <linux/irq.h>
19#include <linux/pm.h>
20#include <linux/platform_device.h>
21#include <linux/input.h>
22#include <linux/clk.h>
23#include <linux/io.h>
24#include <linux/of.h>
25#include <linux/input/matrix_keypad.h>
26
27#define DRV_NAME "lpc32xx_keys"
28
29/*
30 * Key scanner register offsets
31 */
32#define LPC32XX_KS_DEB(x) ((x) + 0x00)
33#define LPC32XX_KS_STATE_COND(x) ((x) + 0x04)
34#define LPC32XX_KS_IRQ(x) ((x) + 0x08)
35#define LPC32XX_KS_SCAN_CTL(x) ((x) + 0x0C)
36#define LPC32XX_KS_FAST_TST(x) ((x) + 0x10)
37#define LPC32XX_KS_MATRIX_DIM(x) ((x) + 0x14) /* 1..8 */
38#define LPC32XX_KS_DATA(x, y) ((x) + 0x40 + ((y) << 2))
39
40#define LPC32XX_KSCAN_DEB_NUM_DEB_PASS(n) ((n) & 0xFF)
41
42#define LPC32XX_KSCAN_SCOND_IN_IDLE 0x0
43#define LPC32XX_KSCAN_SCOND_IN_SCANONCE 0x1
44#define LPC32XX_KSCAN_SCOND_IN_IRQGEN 0x2
45#define LPC32XX_KSCAN_SCOND_IN_SCAN_MATRIX 0x3
46
47#define LPC32XX_KSCAN_IRQ_PENDING_CLR 0x1
48
49#define LPC32XX_KSCAN_SCTRL_SCAN_DELAY(n) ((n) & 0xFF)
50
51#define LPC32XX_KSCAN_FTST_FORCESCANONCE 0x1
52#define LPC32XX_KSCAN_FTST_USE32K_CLK 0x2
53
54#define LPC32XX_KSCAN_MSEL_SELECT(n) ((n) & 0xF)
55
56struct lpc32xx_kscan_drv {
57 struct input_dev *input;
58 struct clk *clk;
59 void __iomem *kscan_base;
60 unsigned int irq;
61
62 u32 matrix_sz; /* Size of matrix in XxY, ie. 3 = 3x3 */
63 u32 deb_clks; /* Debounce clocks (based on 32KHz clock) */
64 u32 scan_delay; /* Scan delay (based on 32KHz clock) */
65
66 unsigned short *keymap; /* Pointer to key map for the scan matrix */
67 unsigned int row_shift;
68
69 u8 lastkeystates[8];
70};
71
72static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)
73{
74 struct input_dev *input = kscandat->input;
75 unsigned row, changed, scancode, keycode;
76 u8 key;
77
78 key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, col));
79 changed = key ^ kscandat->lastkeystates[col];
80 kscandat->lastkeystates[col] = key;
81
82 for (row = 0; changed; row++, changed >>= 1) {
83 if (changed & 1) {
84 /* Key state changed, signal an event */
85 scancode = MATRIX_SCAN_CODE(row, col,
86 kscandat->row_shift);
87 keycode = kscandat->keymap[scancode];
88 input_event(input, EV_MSC, MSC_SCAN, scancode);
89 input_report_key(input, keycode, key & (1 << row));
90 }
91 }
92}
93
94static irqreturn_t lpc32xx_kscan_irq(int irq, void *dev_id)
95{
96 struct lpc32xx_kscan_drv *kscandat = dev_id;
97 int i;
98
99 for (i = 0; i < kscandat->matrix_sz; i++)
100 lpc32xx_mod_states(kscandat, i);
101
102 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
103
104 input_sync(kscandat->input);
105
106 return IRQ_HANDLED;
107}
108
109static int lpc32xx_kscan_open(struct input_dev *dev)
110{
111 struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
112 int error;
113
114 error = clk_prepare_enable(kscandat->clk);
115 if (error)
116 return error;
117
118 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
119
120 return 0;
121}
122
123static void lpc32xx_kscan_close(struct input_dev *dev)
124{
125 struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
126
127 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
128 clk_disable_unprepare(kscandat->clk);
129}
130
131static int lpc32xx_parse_dt(struct device *dev,
132 struct lpc32xx_kscan_drv *kscandat)
133{
134 struct device_node *np = dev->of_node;
135 u32 rows = 0, columns = 0;
136 int err;
137
138 err = matrix_keypad_parse_properties(dev, &rows, &columns);
139 if (err)
140 return err;
141 if (rows != columns) {
142 dev_err(dev, "rows and columns must be equal!\n");
143 return -EINVAL;
144 }
145
146 kscandat->matrix_sz = rows;
147 kscandat->row_shift = get_count_order(columns);
148
149 of_property_read_u32(np, "nxp,debounce-delay-ms", &kscandat->deb_clks);
150 of_property_read_u32(np, "nxp,scan-delay-ms", &kscandat->scan_delay);
151 if (!kscandat->deb_clks || !kscandat->scan_delay) {
152 dev_err(dev, "debounce or scan delay not specified\n");
153 return -EINVAL;
154 }
155
156 return 0;
157}
158
159static int lpc32xx_kscan_probe(struct platform_device *pdev)
160{
161 struct lpc32xx_kscan_drv *kscandat;
162 struct input_dev *input;
163 size_t keymap_size;
164 int error;
165 int irq;
166
167 irq = platform_get_irq(pdev, 0);
168 if (irq < 0)
169 return -EINVAL;
170
171 kscandat = devm_kzalloc(&pdev->dev, sizeof(*kscandat),
172 GFP_KERNEL);
173 if (!kscandat)
174 return -ENOMEM;
175
176 error = lpc32xx_parse_dt(&pdev->dev, kscandat);
177 if (error) {
178 dev_err(&pdev->dev, "failed to parse device tree\n");
179 return error;
180 }
181
182 keymap_size = sizeof(kscandat->keymap[0]) *
183 (kscandat->matrix_sz << kscandat->row_shift);
184 kscandat->keymap = devm_kzalloc(&pdev->dev, keymap_size, GFP_KERNEL);
185 if (!kscandat->keymap)
186 return -ENOMEM;
187
188 kscandat->input = input = devm_input_allocate_device(&pdev->dev);
189 if (!input) {
190 dev_err(&pdev->dev, "failed to allocate input device\n");
191 return -ENOMEM;
192 }
193
194 /* Setup key input */
195 input->name = pdev->name;
196 input->phys = "lpc32xx/input0";
197 input->id.vendor = 0x0001;
198 input->id.product = 0x0001;
199 input->id.version = 0x0100;
200 input->open = lpc32xx_kscan_open;
201 input->close = lpc32xx_kscan_close;
202 input->dev.parent = &pdev->dev;
203
204 input_set_capability(input, EV_MSC, MSC_SCAN);
205
206 error = matrix_keypad_build_keymap(NULL, NULL,
207 kscandat->matrix_sz,
208 kscandat->matrix_sz,
209 kscandat->keymap, kscandat->input);
210 if (error) {
211 dev_err(&pdev->dev, "failed to build keymap\n");
212 return error;
213 }
214
215 input_set_drvdata(kscandat->input, kscandat);
216
217 kscandat->kscan_base = devm_platform_ioremap_resource(pdev, 0);
218 if (IS_ERR(kscandat->kscan_base))
219 return PTR_ERR(kscandat->kscan_base);
220
221 /* Get the key scanner clock */
222 kscandat->clk = devm_clk_get(&pdev->dev, NULL);
223 if (IS_ERR(kscandat->clk)) {
224 dev_err(&pdev->dev, "failed to get clock\n");
225 return PTR_ERR(kscandat->clk);
226 }
227
228 /* Configure the key scanner */
229 error = clk_prepare_enable(kscandat->clk);
230 if (error)
231 return error;
232
233 writel(kscandat->deb_clks, LPC32XX_KS_DEB(kscandat->kscan_base));
234 writel(kscandat->scan_delay, LPC32XX_KS_SCAN_CTL(kscandat->kscan_base));
235 writel(LPC32XX_KSCAN_FTST_USE32K_CLK,
236 LPC32XX_KS_FAST_TST(kscandat->kscan_base));
237 writel(kscandat->matrix_sz,
238 LPC32XX_KS_MATRIX_DIM(kscandat->kscan_base));
239 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
240 clk_disable_unprepare(kscandat->clk);
241
242 error = devm_request_irq(&pdev->dev, irq, lpc32xx_kscan_irq, 0,
243 pdev->name, kscandat);
244 if (error) {
245 dev_err(&pdev->dev, "failed to request irq\n");
246 return error;
247 }
248
249 error = input_register_device(kscandat->input);
250 if (error) {
251 dev_err(&pdev->dev, "failed to register input device\n");
252 return error;
253 }
254
255 platform_set_drvdata(pdev, kscandat);
256
257 return 0;
258}
259
260static int lpc32xx_kscan_suspend(struct device *dev)
261{
262 struct platform_device *pdev = to_platform_device(dev);
263 struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
264 struct input_dev *input = kscandat->input;
265
266 mutex_lock(&input->mutex);
267
268 if (input_device_enabled(input)) {
269 /* Clear IRQ and disable clock */
270 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
271 clk_disable_unprepare(kscandat->clk);
272 }
273
274 mutex_unlock(&input->mutex);
275 return 0;
276}
277
278static int lpc32xx_kscan_resume(struct device *dev)
279{
280 struct platform_device *pdev = to_platform_device(dev);
281 struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
282 struct input_dev *input = kscandat->input;
283 int retval = 0;
284
285 mutex_lock(&input->mutex);
286
287 if (input_device_enabled(input)) {
288 /* Enable clock and clear IRQ */
289 retval = clk_prepare_enable(kscandat->clk);
290 if (retval == 0)
291 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
292 }
293
294 mutex_unlock(&input->mutex);
295 return retval;
296}
297
298static DEFINE_SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,
299 lpc32xx_kscan_resume);
300
301static const struct of_device_id lpc32xx_kscan_match[] = {
302 { .compatible = "nxp,lpc3220-key" },
303 {},
304};
305MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);
306
307static struct platform_driver lpc32xx_kscan_driver = {
308 .probe = lpc32xx_kscan_probe,
309 .driver = {
310 .name = DRV_NAME,
311 .pm = pm_sleep_ptr(&lpc32xx_kscan_pm_ops),
312 .of_match_table = lpc32xx_kscan_match,
313 }
314};
315
316module_platform_driver(lpc32xx_kscan_driver);
317
318MODULE_LICENSE("GPL");
319MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
320MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
321MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");
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
66struct 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
83static 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
105static 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
120static 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
134static 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
142static 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
170static 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
295err_free_irq:
296 free_irq(irq, kscandat);
297err_clk_put:
298 clk_put(kscandat->clk);
299err_unmap:
300 iounmap(kscandat->kscan_base);
301err_release_memregion:
302 release_mem_region(kscandat->iores->start,
303 resource_size(kscandat->iores));
304err_free_input:
305 input_free_device(kscandat->input);
306err_free_keymap:
307 kfree(kscandat->keymap);
308err_free_mem:
309 kfree(kscandat);
310
311 return error;
312}
313
314static 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
331static 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
349static 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
370static SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,
371 lpc32xx_kscan_resume);
372
373static const struct of_device_id lpc32xx_kscan_match[] = {
374 { .compatible = "nxp,lpc3220-key" },
375 {},
376};
377MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);
378
379static 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
390module_platform_driver(lpc32xx_kscan_driver);
391
392MODULE_LICENSE("GPL");
393MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
394MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
395MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");