1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
  4 */
  5
  6#include <linux/input/matrix_keypad.h>
  7#include <linux/platform_device.h>
  8#include <linux/interrupt.h>
  9#include <linux/io.h>
 10#include <linux/delay.h>
 11#include <linux/input.h>
 12#include <linux/slab.h>
 13#include <linux/clk.h>
 14#include <linux/module.h>
 15#include <linux/of.h>
 16
 17#define KEYPAD_SCAN_MODE	0x00
 18#define KEYPAD_CNTL		0x04
 19#define KEYPAD_INT		0x08
 20#define KEYPAD_INTMSK		0x0C
 21
 22#define KEYPAD_DATA		0x10
 23#define KEYPAD_GPIO		0x30
 24
 25#define KEYPAD_UNKNOWN_INT	0x40
 26#define KEYPAD_UNKNOWN_INT_STS	0x44
 27
 28#define KEYPAD_BITMASK_COLS	11
 29#define KEYPAD_BITMASK_ROWS	8
 30
 31struct nspire_keypad {
 32	void __iomem *reg_base;
 33	u32 int_mask;
 34
 35	struct input_dev *input;
 36	struct clk *clk;
 37
 38	struct matrix_keymap_data *keymap;
 39	int row_shift;
 40
 41	/* Maximum delay estimated assuming 33MHz APB */
 42	u32 scan_interval;	/* In microseconds (~2000us max) */
 43	u32 row_delay;		/* In microseconds (~500us max) */
 44
 45	u16 state[KEYPAD_BITMASK_ROWS];
 46
 47	bool active_low;
 48};
 49
 50static irqreturn_t nspire_keypad_irq(int irq, void *dev_id)
 51{
 52	struct nspire_keypad *keypad = dev_id;
 53	struct input_dev *input = keypad->input;
 54	unsigned short *keymap = input->keycode;
 55	unsigned int code;
 56	int row, col;
 57	u32 int_sts;
 58	u16 state[8];
 59	u16 bits, changed;
 60
 61	int_sts = readl(keypad->reg_base + KEYPAD_INT) & keypad->int_mask;
 62	if (!int_sts)
 63		return IRQ_NONE;
 64
 65	memcpy_fromio(state, keypad->reg_base + KEYPAD_DATA, sizeof(state));
 66
 67	for (row = 0; row < KEYPAD_BITMASK_ROWS; row++) {
 68		bits = state[row];
 69		if (keypad->active_low)
 70			bits = ~bits;
 71
 72		changed = bits ^ keypad->state[row];
 73		if (!changed)
 74			continue;
 75
 76		keypad->state[row] = bits;
 77
 78		for (col = 0; col < KEYPAD_BITMASK_COLS; col++) {
 79			if (!(changed & (1U << col)))
 80				continue;
 81
 82			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
 83			input_event(input, EV_MSC, MSC_SCAN, code);
 84			input_report_key(input, keymap[code],
 85					 bits & (1U << col));
 86		}
 87	}
 88
 89	input_sync(input);
 90
 91	writel(0x3, keypad->reg_base + KEYPAD_INT);
 92
 93	return IRQ_HANDLED;
 94}
 95
 96static int nspire_keypad_open(struct input_dev *input)
 97{
 98	struct nspire_keypad *keypad = input_get_drvdata(input);
 99	unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;
100	int error;
101
102	error = clk_prepare_enable(keypad->clk);
103	if (error)
104		return error;
105
106	cycles_per_us = (clk_get_rate(keypad->clk) / 1000000);
107	if (cycles_per_us == 0)
108		cycles_per_us = 1;
109
110	delay_cycles = cycles_per_us * keypad->scan_interval;
111	WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */
112	delay_cycles &= 0xffff;
113
114	row_delay_cycles = cycles_per_us * keypad->row_delay;
115	WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */
116	row_delay_cycles &= 0x3fff;
117
118	val |= 3 << 0; /* Set scan mode to 3 (continuous scan) */
119	val |= row_delay_cycles << 2; /* Delay between scanning each row */
120	val |= delay_cycles << 16; /* Delay between scans */
121	writel(val, keypad->reg_base + KEYPAD_SCAN_MODE);
122
123	val = (KEYPAD_BITMASK_ROWS & 0xff) | (KEYPAD_BITMASK_COLS & 0xff)<<8;
124	writel(val, keypad->reg_base + KEYPAD_CNTL);
125
126	/* Enable interrupts */
127	keypad->int_mask = 1 << 1;
128	writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK);
129
130	return 0;
131}
132
133static void nspire_keypad_close(struct input_dev *input)
134{
135	struct nspire_keypad *keypad = input_get_drvdata(input);
136
137	/* Disable interrupts */
138	writel(0, keypad->reg_base + KEYPAD_INTMSK);
139	/* Acknowledge existing interrupts */
140	writel(~0, keypad->reg_base + KEYPAD_INT);
141
142	clk_disable_unprepare(keypad->clk);
143}
144
145static int nspire_keypad_probe(struct platform_device *pdev)
146{
147	const struct device_node *of_node = pdev->dev.of_node;
148	struct nspire_keypad *keypad;
149	struct input_dev *input;
150	struct resource *res;
151	int irq;
152	int error;
153
154	irq = platform_get_irq(pdev, 0);
155	if (irq < 0)
156		return -EINVAL;
157
158	keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad),
159			      GFP_KERNEL);
160	if (!keypad) {
161		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
162		return -ENOMEM;
163	}
164
165	keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS);
166
167	error = of_property_read_u32(of_node, "scan-interval",
168				     &keypad->scan_interval);
169	if (error) {
170		dev_err(&pdev->dev, "failed to get scan-interval\n");
171		return error;
172	}
173
174	error = of_property_read_u32(of_node, "row-delay",
175				     &keypad->row_delay);
176	if (error) {
177		dev_err(&pdev->dev, "failed to get row-delay\n");
178		return error;
179	}
180
181	keypad->active_low = of_property_read_bool(of_node, "active-low");
182
183	keypad->clk = devm_clk_get(&pdev->dev, NULL);
184	if (IS_ERR(keypad->clk)) {
185		dev_err(&pdev->dev, "unable to get clock\n");
186		return PTR_ERR(keypad->clk);
187	}
188
189	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
190	keypad->reg_base = devm_ioremap_resource(&pdev->dev, res);
191	if (IS_ERR(keypad->reg_base))
192		return PTR_ERR(keypad->reg_base);
193
194	keypad->input = input = devm_input_allocate_device(&pdev->dev);
195	if (!input) {
196		dev_err(&pdev->dev, "failed to allocate input device\n");
197		return -ENOMEM;
198	}
199
200	error = clk_prepare_enable(keypad->clk);
201	if (error) {
202		dev_err(&pdev->dev, "failed to enable clock\n");
203		return error;
204	}
205
206	/* Disable interrupts */
207	writel(0, keypad->reg_base + KEYPAD_INTMSK);
208	/* Acknowledge existing interrupts */
209	writel(~0, keypad->reg_base + KEYPAD_INT);
210
211	/* Disable GPIO interrupts to prevent hanging on touchpad */
212	/* Possibly used to detect touchpad events */
213	writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
214	/* Acknowledge existing GPIO interrupts */
215	writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
216
217	clk_disable_unprepare(keypad->clk);
218
219	input_set_drvdata(input, keypad);
220
221	input->id.bustype = BUS_HOST;
222	input->name = "nspire-keypad";
223	input->open = nspire_keypad_open;
224	input->close = nspire_keypad_close;
225
226	__set_bit(EV_KEY, input->evbit);
227	__set_bit(EV_REP, input->evbit);
228	input_set_capability(input, EV_MSC, MSC_SCAN);
229
230	error = matrix_keypad_build_keymap(NULL, NULL,
231					   KEYPAD_BITMASK_ROWS,
232					   KEYPAD_BITMASK_COLS,
233					   NULL, input);
234	if (error) {
235		dev_err(&pdev->dev, "building keymap failed\n");
236		return error;
237	}
238
239	error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0,
240				 "nspire_keypad", keypad);
241	if (error) {
242		dev_err(&pdev->dev, "allocate irq %d failed\n", irq);
243		return error;
244	}
245
246	error = input_register_device(input);
247	if (error) {
248		dev_err(&pdev->dev,
249			"unable to register input device: %d\n", error);
250		return error;
251	}
252
253	dev_dbg(&pdev->dev,
254		"TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n",
255		res, keypad->row_delay, keypad->scan_interval,
256		keypad->active_low ? ", active_low" : "");
257
258	return 0;
259}
260
261static const struct of_device_id nspire_keypad_dt_match[] = {
262	{ .compatible = "ti,nspire-keypad" },
263	{ },
264};
265MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match);
266
267static struct platform_driver nspire_keypad_driver = {
268	.driver = {
269		.name = "nspire-keypad",
270		.of_match_table = nspire_keypad_dt_match,
271	},
272	.probe = nspire_keypad_probe,
273};
274
275module_platform_driver(nspire_keypad_driver);
276
277MODULE_LICENSE("GPL");
278MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver");

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
  4 */
  5
  6#include <linux/input/matrix_keypad.h>
  7#include <linux/platform_device.h>
  8#include <linux/interrupt.h>
  9#include <linux/io.h>
 10#include <linux/delay.h>
 11#include <linux/input.h>
 12#include <linux/slab.h>
 13#include <linux/clk.h>
 14#include <linux/module.h>
 15#include <linux/of.h>
 16
 17#define KEYPAD_SCAN_MODE	0x00
 18#define KEYPAD_CNTL		0x04
 19#define KEYPAD_INT		0x08
 20#define KEYPAD_INTMSK		0x0C
 21
 22#define KEYPAD_DATA		0x10
 23#define KEYPAD_GPIO		0x30
 24
 25#define KEYPAD_UNKNOWN_INT	0x40
 26#define KEYPAD_UNKNOWN_INT_STS	0x44
 27
 28#define KEYPAD_BITMASK_COLS	11
 29#define KEYPAD_BITMASK_ROWS	8
 30
 31struct nspire_keypad {
 32	void __iomem *reg_base;
 33	u32 int_mask;
 34
 35	struct input_dev *input;
 36	struct clk *clk;
 37
 38	struct matrix_keymap_data *keymap;
 39	int row_shift;
 40
 41	/* Maximum delay estimated assuming 33MHz APB */
 42	u32 scan_interval;	/* In microseconds (~2000us max) */
 43	u32 row_delay;		/* In microseconds (~500us max) */
 44
 45	u16 state[KEYPAD_BITMASK_ROWS];
 46
 47	bool active_low;
 48};
 49
 50static irqreturn_t nspire_keypad_irq(int irq, void *dev_id)
 51{
 52	struct nspire_keypad *keypad = dev_id;
 53	struct input_dev *input = keypad->input;
 54	unsigned short *keymap = input->keycode;
 55	unsigned int code;
 56	int row, col;
 57	u32 int_sts;
 58	u16 state[8];
 59	u16 bits, changed;
 60
 61	int_sts = readl(keypad->reg_base + KEYPAD_INT) & keypad->int_mask;
 62	if (!int_sts)
 63		return IRQ_NONE;
 64
 65	memcpy_fromio(state, keypad->reg_base + KEYPAD_DATA, sizeof(state));
 66
 67	for (row = 0; row < KEYPAD_BITMASK_ROWS; row++) {
 68		bits = state[row];
 69		if (keypad->active_low)
 70			bits = ~bits;
 71
 72		changed = bits ^ keypad->state[row];
 73		if (!changed)
 74			continue;
 75
 76		keypad->state[row] = bits;
 77
 78		for (col = 0; col < KEYPAD_BITMASK_COLS; col++) {
 79			if (!(changed & (1U << col)))
 80				continue;
 81
 82			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
 83			input_event(input, EV_MSC, MSC_SCAN, code);
 84			input_report_key(input, keymap[code],
 85					 bits & (1U << col));
 86		}
 87	}
 88
 89	input_sync(input);
 90
 91	writel(0x3, keypad->reg_base + KEYPAD_INT);
 92
 93	return IRQ_HANDLED;
 94}
 95
 96static int nspire_keypad_open(struct input_dev *input)
 97{
 98	struct nspire_keypad *keypad = input_get_drvdata(input);
 99	unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;
100	int error;
101
102	error = clk_prepare_enable(keypad->clk);
103	if (error)
104		return error;
105
106	cycles_per_us = (clk_get_rate(keypad->clk) / 1000000);
107	if (cycles_per_us == 0)
108		cycles_per_us = 1;
109
110	delay_cycles = cycles_per_us * keypad->scan_interval;
111	WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */
112	delay_cycles &= 0xffff;
113
114	row_delay_cycles = cycles_per_us * keypad->row_delay;
115	WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */
116	row_delay_cycles &= 0x3fff;
117
118	val |= 3 << 0; /* Set scan mode to 3 (continuous scan) */
119	val |= row_delay_cycles << 2; /* Delay between scanning each row */
120	val |= delay_cycles << 16; /* Delay between scans */
121	writel(val, keypad->reg_base + KEYPAD_SCAN_MODE);
122
123	val = (KEYPAD_BITMASK_ROWS & 0xff) | (KEYPAD_BITMASK_COLS & 0xff)<<8;
124	writel(val, keypad->reg_base + KEYPAD_CNTL);
125
126	/* Enable interrupts */
127	keypad->int_mask = 1 << 1;
128	writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK);
129
130	return 0;
131}
132
133static void nspire_keypad_close(struct input_dev *input)
134{
135	struct nspire_keypad *keypad = input_get_drvdata(input);
136
137	/* Disable interrupts */
138	writel(0, keypad->reg_base + KEYPAD_INTMSK);
139	/* Acknowledge existing interrupts */
140	writel(~0, keypad->reg_base + KEYPAD_INT);
141
142	clk_disable_unprepare(keypad->clk);
143}
144
145static int nspire_keypad_probe(struct platform_device *pdev)
146{
147	const struct device_node *of_node = pdev->dev.of_node;
148	struct nspire_keypad *keypad;
149	struct input_dev *input;
150	struct resource *res;
151	int irq;
152	int error;
153
154	irq = platform_get_irq(pdev, 0);
155	if (irq < 0)
156		return -EINVAL;
157
158	keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad),
159			      GFP_KERNEL);
160	if (!keypad) {
161		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
162		return -ENOMEM;
163	}
164
165	keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS);
166
167	error = of_property_read_u32(of_node, "scan-interval",
168				     &keypad->scan_interval);
169	if (error) {
170		dev_err(&pdev->dev, "failed to get scan-interval\n");
171		return error;
172	}
173
174	error = of_property_read_u32(of_node, "row-delay",
175				     &keypad->row_delay);
176	if (error) {
177		dev_err(&pdev->dev, "failed to get row-delay\n");
178		return error;
179	}
180
181	keypad->active_low = of_property_read_bool(of_node, "active-low");
182
183	keypad->clk = devm_clk_get(&pdev->dev, NULL);
184	if (IS_ERR(keypad->clk)) {
185		dev_err(&pdev->dev, "unable to get clock\n");
186		return PTR_ERR(keypad->clk);
187	}
188
189	keypad->reg_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 
190	if (IS_ERR(keypad->reg_base))
191		return PTR_ERR(keypad->reg_base);
192
193	keypad->input = input = devm_input_allocate_device(&pdev->dev);
194	if (!input) {
195		dev_err(&pdev->dev, "failed to allocate input device\n");
196		return -ENOMEM;
197	}
198
199	error = clk_prepare_enable(keypad->clk);
200	if (error) {
201		dev_err(&pdev->dev, "failed to enable clock\n");
202		return error;
203	}
204
205	/* Disable interrupts */
206	writel(0, keypad->reg_base + KEYPAD_INTMSK);
207	/* Acknowledge existing interrupts */
208	writel(~0, keypad->reg_base + KEYPAD_INT);
209
210	/* Disable GPIO interrupts to prevent hanging on touchpad */
211	/* Possibly used to detect touchpad events */
212	writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
213	/* Acknowledge existing GPIO interrupts */
214	writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
215
216	clk_disable_unprepare(keypad->clk);
217
218	input_set_drvdata(input, keypad);
219
220	input->id.bustype = BUS_HOST;
221	input->name = "nspire-keypad";
222	input->open = nspire_keypad_open;
223	input->close = nspire_keypad_close;
224
225	__set_bit(EV_KEY, input->evbit);
226	__set_bit(EV_REP, input->evbit);
227	input_set_capability(input, EV_MSC, MSC_SCAN);
228
229	error = matrix_keypad_build_keymap(NULL, NULL,
230					   KEYPAD_BITMASK_ROWS,
231					   KEYPAD_BITMASK_COLS,
232					   NULL, input);
233	if (error) {
234		dev_err(&pdev->dev, "building keymap failed\n");
235		return error;
236	}
237
238	error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0,
239				 "nspire_keypad", keypad);
240	if (error) {
241		dev_err(&pdev->dev, "allocate irq %d failed\n", irq);
242		return error;
243	}
244
245	error = input_register_device(input);
246	if (error) {
247		dev_err(&pdev->dev,
248			"unable to register input device: %d\n", error);
249		return error;
250	}
251
252	dev_dbg(&pdev->dev,
253		"TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n",
254		res, keypad->row_delay, keypad->scan_interval,
255		keypad->active_low ? ", active_low" : "");
256
257	return 0;
258}
259
260static const struct of_device_id nspire_keypad_dt_match[] = {
261	{ .compatible = "ti,nspire-keypad" },
262	{ },
263};
264MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match);
265
266static struct platform_driver nspire_keypad_driver = {
267	.driver = {
268		.name = "nspire-keypad",
269		.of_match_table = nspire_keypad_dt_match,
270	},
271	.probe = nspire_keypad_probe,
272};
273
274module_platform_driver(nspire_keypad_driver);
275
276MODULE_LICENSE("GPL");
277MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver");