spear-keyboard.c

  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");