1 // SPDX-License-Identifier: GPL-2.0-only
5  * Counter driver for Texas Instruments Enhanced Quadrature Encoder Pulse (eQEP)
9 #include <linux/counter.h>
18 /* 32-bit registers */
19 #define QPOSCNT		0x0
20 #define QPOSINIT	0x4
21 #define QPOSMAX		0x8
22 #define QPOSCMP		0xc
23 #define QPOSILAT	0x10
24 #define QPOSSLAT	0x14
25 #define QPOSLAT		0x18
26 #define QUTMR		0x1c
27 #define QUPRD		0x20
29 /* 16-bit registers */
30 #define QWDTMR		0x0	/* 0x24 */
31 #define QWDPRD		0x2	/* 0x26 */
32 #define QDECCTL		0x4	/* 0x28 */
33 #define QEPCTL		0x6	/* 0x2a */
34 #define QCAPCTL		0x8	/* 0x2c */
35 #define QPOSCTL		0xa	/* 0x2e */
36 #define QEINT		0xc	/* 0x30 */
37 #define QFLG		0xe	/* 0x32 */
38 #define QCLR		0x10	/* 0x34 */
39 #define QFRC		0x12	/* 0x36 */
40 #define QEPSTS		0x14	/* 0x38 */
41 #define QCTMR		0x16	/* 0x3a */
42 #define QCPRD		0x18	/* 0x3c */
43 #define QCTMRLAT	0x1a	/* 0x3e */
44 #define QCPRDLAT	0x1c	/* 0x40 */
68 #define QEPCTL_WDE		BIT(0)
76 /* Position Counter Input Modes */
85 	struct counter_device counter;  member
90 static struct ti_eqep_cnt *ti_eqep_count_from_counter(struct counter_device *counter)  in ti_eqep_count_from_counter()  argument
92 	return counter_priv(counter);  in ti_eqep_count_from_counter()
95 static int ti_eqep_count_read(struct counter_device *counter,  in ti_eqep_count_read()  argument
98 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_count_read()
101 	regmap_read(priv->regmap32, QPOSCNT, &cnt);  in ti_eqep_count_read()
104 	return 0;  in ti_eqep_count_read()
107 static int ti_eqep_count_write(struct counter_device *counter,  in ti_eqep_count_write()  argument
110 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_count_write()
113 	regmap_read(priv->regmap32, QPOSMAX, &max);  in ti_eqep_count_write()
115 		return -EINVAL;  in ti_eqep_count_write()
117 	return regmap_write(priv->regmap32, QPOSCNT, val);  in ti_eqep_count_write()
120 static int ti_eqep_function_read(struct counter_device *counter,  in ti_eqep_function_read()  argument
124 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_function_read()
127 	regmap_read(priv->regmap16, QDECCTL, &qdecctl);  in ti_eqep_function_read()
144 	return 0;  in ti_eqep_function_read()
147 static int ti_eqep_function_write(struct counter_device *counter,  in ti_eqep_function_write()  argument
151 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_function_write()
169 		return -EINVAL;  in ti_eqep_function_write()
172 	return regmap_write_bits(priv->regmap16, QDECCTL, QDECCTL_QSRC,  in ti_eqep_function_write()
176 static int ti_eqep_action_read(struct counter_device *counter,  in ti_eqep_action_read()  argument
181 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_action_read()
186 	err = ti_eqep_function_read(counter, count, &function);  in ti_eqep_action_read()
196 		return 0;  in ti_eqep_action_read()
198 		/* In direction-count mode only rising edge of QEPA is counted  in ti_eqep_action_read()
201 		switch (synapse->signal->id) {  in ti_eqep_action_read()
204 			return 0;  in ti_eqep_action_read()
207 			return 0;  in ti_eqep_action_read()
210 			return -EINVAL;  in ti_eqep_action_read()
214 		/* In up/down-count modes only QEPA is counted and QEPB is not  in ti_eqep_action_read()
217 		switch (synapse->signal->id) {  in ti_eqep_action_read()
219 			err = regmap_read(priv->regmap16, QDECCTL, &qdecctl);  in ti_eqep_action_read()
227 			return 0;  in ti_eqep_action_read()
230 			return 0;  in ti_eqep_action_read()
233 			return -EINVAL;  in ti_eqep_action_read()
237 		return -EINVAL;  in ti_eqep_action_read()
249 static int ti_eqep_position_ceiling_read(struct counter_device *counter,  in ti_eqep_position_ceiling_read()  argument
253 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_position_ceiling_read()
256 	regmap_read(priv->regmap32, QPOSMAX, &qposmax);  in ti_eqep_position_ceiling_read()
260 	return 0;  in ti_eqep_position_ceiling_read()
263 static int ti_eqep_position_ceiling_write(struct counter_device *counter,  in ti_eqep_position_ceiling_write()  argument
267 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_position_ceiling_write()
270 		return -ERANGE;  in ti_eqep_position_ceiling_write()
272 	regmap_write(priv->regmap32, QPOSMAX, ceiling);  in ti_eqep_position_ceiling_write()
274 	return 0;  in ti_eqep_position_ceiling_write()
277 static int ti_eqep_position_enable_read(struct counter_device *counter,  in ti_eqep_position_enable_read()  argument
280 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_position_enable_read()
283 	regmap_read(priv->regmap16, QEPCTL, &qepctl);  in ti_eqep_position_enable_read()
287 	return 0;  in ti_eqep_position_enable_read()
290 static int ti_eqep_position_enable_write(struct counter_device *counter,  in ti_eqep_position_enable_write()  argument
293 	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);  in ti_eqep_position_enable_write()
295 	regmap_write_bits(priv->regmap16, QEPCTL, QEPCTL_PHEN, enable ? -1 : 0);  in ti_eqep_position_enable_write()
297 	return 0;  in ti_eqep_position_enable_write()
346 		.id		= 0,
358 	.name = "32-bit",
366 	.name = "16-bit",
375 	struct device *dev = &pdev->dev;  in ti_eqep_probe()
376 	struct counter_device *counter;  in ti_eqep_probe()  local
381 	counter = devm_counter_alloc(dev, sizeof(*priv));  in ti_eqep_probe()
382 	if (!counter)  in ti_eqep_probe()
383 		return -ENOMEM;  in ti_eqep_probe()
384 	priv = counter_priv(counter);  in ti_eqep_probe()
386 	base = devm_platform_ioremap_resource(pdev, 0);  in ti_eqep_probe()
390 	priv->regmap32 = devm_regmap_init_mmio(dev, base,  in ti_eqep_probe()
392 	if (IS_ERR(priv->regmap32))  in ti_eqep_probe()
393 		return PTR_ERR(priv->regmap32);  in ti_eqep_probe()
395 	priv->regmap16 = devm_regmap_init_mmio(dev, base + 0x24,  in ti_eqep_probe()
397 	if (IS_ERR(priv->regmap16))  in ti_eqep_probe()
398 		return PTR_ERR(priv->regmap16);  in ti_eqep_probe()
400 	counter->name = dev_name(dev);  in ti_eqep_probe()
401 	counter->parent = dev;  in ti_eqep_probe()
402 	counter->ops = &ti_eqep_counter_ops;  in ti_eqep_probe()
403 	counter->counts = ti_eqep_counts;  in ti_eqep_probe()
404 	counter->num_counts = ARRAY_SIZE(ti_eqep_counts);  in ti_eqep_probe()
405 	counter->signals = ti_eqep_signals;  in ti_eqep_probe()
406 	counter->num_signals = ARRAY_SIZE(ti_eqep_signals);  in ti_eqep_probe()
408 	platform_set_drvdata(pdev, counter);  in ti_eqep_probe()
418 	err = counter_add(counter);  in ti_eqep_probe()
419 	if (err < 0) {  in ti_eqep_probe()
425 	return 0;  in ti_eqep_probe()
430 	struct counter_device *counter = platform_get_drvdata(pdev);  in ti_eqep_remove()  local
431 	struct device *dev = &pdev->dev;  in ti_eqep_remove()
433 	counter_unregister(counter);  in ti_eqep_remove()
437 	return 0;  in ti_eqep_remove()
441 	{ .compatible = "ti,am3352-eqep", },
450 		.name = "ti-eqep-cnt",
457 MODULE_DESCRIPTION("TI eQEP counter driver");
459 MODULE_IMPORT_NS(COUNTER);