tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * SPEAr Keyboard Driver
3 * Based on omap-keypad driver
4 *
5 * Copyright (C) 2010 ST Microelectronics
6 * Rajeev Kumar <rajeevkumar.linux@gmail.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13#include <linux/clk.h>
14#include <linux/errno.h>
15#include <linux/interrupt.h>
16#include <linux/input.h>
17#include <linux/input/matrix_keypad.h>
18#include <linux/io.h>
19#include <linux/irq.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/platform_device.h>
24#include <linux/slab.h>
25#include <linux/types.h>
26
27/* Keyboard Registers */
28#define MODE_CTL_REG 0x00
29#define STATUS_REG 0x0C
30#define DATA_REG 0x10
31#define INTR_MASK 0x54
32
33/* Register Values */
34#define NUM_ROWS 16
35#define NUM_COLS 16
36#define MODE_CTL_PCLK_FREQ_SHIFT 9
37#define MODE_CTL_PCLK_FREQ_MSK 0x7F
38
39#define MODE_CTL_KEYBOARD (0x2 << 0)
40#define MODE_CTL_SCAN_RATE_10 (0x0 << 2)
41#define MODE_CTL_SCAN_RATE_20 (0x1 << 2)
42#define MODE_CTL_SCAN_RATE_40 (0x2 << 2)
43#define MODE_CTL_SCAN_RATE_80 (0x3 << 2)
44#define MODE_CTL_KEYNUM_SHIFT 6
45#define MODE_CTL_START_SCAN (0x1 << 8)
46
47#define STATUS_DATA_AVAIL (0x1 << 1)
48
49#define DATA_ROW_MASK 0xF0
50#define DATA_COLUMN_MASK 0x0F
51
52#define ROW_SHIFT 4
53
54struct spear_kbd {
55 struct input_dev *input;
56 void __iomem *io_base;
57 struct clk *clk;
58 unsigned int irq;
59 u32 mode;
60 u32 suspended_rate;
61 u32 mode_ctl_reg;
62 unsigned short last_key;
63 unsigned short keycodes[NUM_ROWS * NUM_COLS];
64 bool irq_wake_enabled;
65};
66
67static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
68{
69 struct spear_kbd *kbd = dev_id;
70 struct input_dev *input = kbd->input;
71 unsigned int key;
72 u32 sts, val;
73
74 sts = readl_relaxed(kbd->io_base + STATUS_REG);
75 if (!(sts & STATUS_DATA_AVAIL))
76 return IRQ_NONE;
77
78 if (kbd->last_key != KEY_RESERVED) {
79 input_report_key(input, kbd->last_key, 0);
80 kbd->last_key = KEY_RESERVED;
81 }
82
83 /* following reads active (row, col) pair */
84 val = readl_relaxed(kbd->io_base + DATA_REG) &
85 (DATA_ROW_MASK | DATA_COLUMN_MASK);
86 key = kbd->keycodes[val];
87
88 input_event(input, EV_MSC, MSC_SCAN, val);
89 input_report_key(input, key, 1);
90 input_sync(input);
91
92 kbd->last_key = key;
93
94 /* clear interrupt */
95 writel_relaxed(0, kbd->io_base + STATUS_REG);
96
97 return IRQ_HANDLED;
98}
99
100static int spear_kbd_open(struct input_dev *dev)
101{
102 struct spear_kbd *kbd = input_get_drvdata(dev);
103 int error;
104 u32 val;
105
106 kbd->last_key = KEY_RESERVED;
107
108 error = clk_enable(kbd->clk);
109 if (error)
110 return error;
111
112 /* keyboard rate to be programmed is input clock (in MHz) - 1 */
113 val = clk_get_rate(kbd->clk) / 1000000 - 1;
114 val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
115
116 /* program keyboard */
117 val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
118 (kbd->mode << MODE_CTL_KEYNUM_SHIFT);
119 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
120 writel_relaxed(1, kbd->io_base + STATUS_REG);
121
122 /* start key scan */
123 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
124 val |= MODE_CTL_START_SCAN;
125 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
126
127 return 0;
128}
129
130static void spear_kbd_close(struct input_dev *dev)
131{
132 struct spear_kbd *kbd = input_get_drvdata(dev);
133 u32 val;
134
135 /* stop key scan */
136 val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
137 val &= ~MODE_CTL_START_SCAN;
138 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
139
140 clk_disable(kbd->clk);
141
142 kbd->last_key = KEY_RESERVED;
143}
144
145static int spear_kbd_probe(struct platform_device *pdev)
146{
147 struct spear_kbd *kbd;
148 struct input_dev *input_dev;
149 int irq;
150 int error;
151
152 irq = platform_get_irq(pdev, 0);
153 if (irq < 0)
154 return irq;
155
156 kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
157 if (!kbd) {
158 dev_err(&pdev->dev, "not enough memory for driver data\n");
159 return -ENOMEM;
160 }
161
162 error = device_property_read_u32(&pdev->dev, "st,mode", &kbd->mode);
163 if (error) {
164 dev_err(&pdev->dev, "Invalid or missing mode\n");
165 return error;
166 }
167
168 device_property_read_u32(&pdev->dev, "suspended_rate", &kbd->suspended_rate);
169
170 input_dev = devm_input_allocate_device(&pdev->dev);
171 if (!input_dev) {
172 dev_err(&pdev->dev, "unable to allocate input device\n");
173 return -ENOMEM;
174 }
175
176 kbd->input = input_dev;
177 kbd->irq = irq;
178
179 kbd->io_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
180 if (IS_ERR(kbd->io_base))
181 return PTR_ERR(kbd->io_base);
182
183 kbd->clk = devm_clk_get_prepared(&pdev->dev, NULL);
184 if (IS_ERR(kbd->clk))
185 return PTR_ERR(kbd->clk);
186
187 input_dev->name = "Spear Keyboard";
188 input_dev->phys = "keyboard/input0";
189 input_dev->id.bustype = BUS_HOST;
190 input_dev->id.vendor = 0x0001;
191 input_dev->id.product = 0x0001;
192 input_dev->id.version = 0x0100;
193 input_dev->open = spear_kbd_open;
194 input_dev->close = spear_kbd_close;
195
196 error = matrix_keypad_build_keymap(NULL, NULL, NUM_ROWS, NUM_COLS,
197 kbd->keycodes, input_dev);
198 if (error) {
199 dev_err(&pdev->dev, "Failed to build keymap\n");
200 return error;
201 }
202
203 if (device_property_read_bool(&pdev->dev, "autorepeat"))
204 __set_bit(EV_REP, input_dev->evbit);
205 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
206
207 input_set_drvdata(input_dev, kbd);
208
209 error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
210 "keyboard", kbd);
211 if (error) {
212 dev_err(&pdev->dev, "request_irq failed\n");
213 return error;
214 }
215
216 error = input_register_device(input_dev);
217 if (error) {
218 dev_err(&pdev->dev, "Unable to register keyboard device\n");
219 return error;
220 }
221
222 device_init_wakeup(&pdev->dev, 1);
223 platform_set_drvdata(pdev, kbd);
224
225 return 0;
226}
227
228static int spear_kbd_suspend(struct device *dev)
229{
230 struct platform_device *pdev = to_platform_device(dev);
231 struct spear_kbd *kbd = platform_get_drvdata(pdev);
232 struct input_dev *input_dev = kbd->input;
233 unsigned int rate = 0, mode_ctl_reg, val;
234
235 guard(mutex)(&input_dev->mutex);
236
237 /* explicitly enable clock as we may program device */
238 clk_enable(kbd->clk);
239
240 mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
241
242 if (device_may_wakeup(&pdev->dev)) {
243 if (!enable_irq_wake(kbd->irq))
244 kbd->irq_wake_enabled = true;
245
246 /*
247 * reprogram the keyboard operating frequency as on some
248 * platform it may change during system suspended
249 */
250 if (kbd->suspended_rate)
251 rate = kbd->suspended_rate / 1000000 - 1;
252 else
253 rate = clk_get_rate(kbd->clk) / 1000000 - 1;
254
255 val = mode_ctl_reg &
256 ~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
257 val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
258 << MODE_CTL_PCLK_FREQ_SHIFT;
259 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
260
261 } else {
262 if (input_device_enabled(input_dev)) {
263 writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
264 kbd->io_base + MODE_CTL_REG);
265 clk_disable(kbd->clk);
266 }
267 }
268
269 /* store current configuration */
270 if (input_device_enabled(input_dev))
271 kbd->mode_ctl_reg = mode_ctl_reg;
272
273 /* restore previous clk state */
274 clk_disable(kbd->clk);
275
276 return 0;
277}
278
279static int spear_kbd_resume(struct device *dev)
280{
281 struct platform_device *pdev = to_platform_device(dev);
282 struct spear_kbd *kbd = platform_get_drvdata(pdev);
283 struct input_dev *input_dev = kbd->input;
284
285 guard(mutex)(&input_dev->mutex);
286
287 if (device_may_wakeup(&pdev->dev)) {
288 if (kbd->irq_wake_enabled) {
289 kbd->irq_wake_enabled = false;
290 disable_irq_wake(kbd->irq);
291 }
292 } else {
293 if (input_device_enabled(input_dev))
294 clk_enable(kbd->clk);
295 }
296
297 /* restore current configuration */
298 if (input_device_enabled(input_dev))
299 writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
300
301 return 0;
302}
303
304static DEFINE_SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops,
305 spear_kbd_suspend, spear_kbd_resume);
306
307#ifdef CONFIG_OF
308static const struct of_device_id spear_kbd_id_table[] = {
309 { .compatible = "st,spear300-kbd" },
310 {}
311};
312MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
313#endif
314
315static struct platform_driver spear_kbd_driver = {
316 .probe = spear_kbd_probe,
317 .driver = {
318 .name = "keyboard",
319 .pm = pm_sleep_ptr(&spear_kbd_pm_ops),
320 .of_match_table = of_match_ptr(spear_kbd_id_table),
321 },
322};
323module_platform_driver(spear_kbd_driver);
324
325MODULE_AUTHOR("Rajeev Kumar");
326MODULE_DESCRIPTION("SPEAr Keyboard Driver");
327MODULE_LICENSE("GPL");