1 // SPDX-License-Identifier: GPL-2.0
3  * Flex Timer Module Quadrature decoder
5  * This module implements a driver for decoding the FTM quadrature
9 #include <linux/fsl/ftm.h>
19 #define FTM_FIELD_UPDATE(ftm, offset, mask, val)			\  argument
22 		ftm_read(ftm, offset, &flags);				\
25 		ftm_write(ftm, offset, flags);				\
35 static void ftm_read(struct ftm_quaddec *ftm, uint32_t offset, uint32_t *data)  in ftm_read()  argument
37 	if (ftm->big_endian)  in ftm_read()
38 		*data = ioread32be(ftm->ftm_base + offset);  in ftm_read()
40 		*data = ioread32(ftm->ftm_base + offset);  in ftm_read()
43 static void ftm_write(struct ftm_quaddec *ftm, uint32_t offset, uint32_t data)  in ftm_write()  argument
45 	if (ftm->big_endian)  in ftm_write()
46 		iowrite32be(data, ftm->ftm_base + offset);  in ftm_write()
48 		iowrite32(data, ftm->ftm_base + offset);  in ftm_write()
52 static void ftm_clear_write_protection(struct ftm_quaddec *ftm)  in ftm_clear_write_protection()  argument
57 	ftm_read(ftm, FTM_FMS, &flag);  in ftm_clear_write_protection()
60 		FTM_FIELD_UPDATE(ftm, FTM_MODE, FTM_MODE_WPDIS, 1);  in ftm_clear_write_protection()
63 static void ftm_set_write_protection(struct ftm_quaddec *ftm)  in ftm_set_write_protection()  argument
65 	FTM_FIELD_UPDATE(ftm, FTM_FMS, FTM_FMS_WPEN, 1);  in ftm_set_write_protection()
68 static void ftm_reset_counter(struct ftm_quaddec *ftm)  in ftm_reset_counter()  argument
71 	ftm_write(ftm, FTM_CNT, 0x0);  in ftm_reset_counter()
74 static void ftm_quaddec_init(struct ftm_quaddec *ftm)  in ftm_quaddec_init()  argument
76 	ftm_clear_write_protection(ftm);  in ftm_quaddec_init()
83 	ftm_write(ftm, FTM_MODE, FTM_MODE_FTMEN);  in ftm_quaddec_init()
84 	ftm_write(ftm, FTM_CNTIN, 0x0000);  in ftm_quaddec_init()
85 	ftm_write(ftm, FTM_MOD, 0xffff);  in ftm_quaddec_init()
86 	ftm_write(ftm, FTM_CNT, 0x0);  in ftm_quaddec_init()
88 	ftm_write(ftm, FTM_SC, FTM_SC_PS_1);  in ftm_quaddec_init()
91 	ftm_write(ftm, FTM_QDCTRL, FTM_QDCTRL_QUADEN);  in ftm_quaddec_init()
94 	ftm_write(ftm, FTM_POL, 0x0);  in ftm_quaddec_init()
95 	ftm_write(ftm, FTM_FLTCTRL, 0x0);  in ftm_quaddec_init()
96 	ftm_write(ftm, FTM_SYNCONF, 0x0);  in ftm_quaddec_init()
97 	ftm_write(ftm, FTM_SYNC, 0xffff);  in ftm_quaddec_init()
99 	/* Lock the FTM */  in ftm_quaddec_init()
100 	ftm_set_write_protection(ftm);  in ftm_quaddec_init()
103 static void ftm_quaddec_disable(void *ftm)  in ftm_quaddec_disable()  argument
105 	struct ftm_quaddec *ftm_qua = ftm;  in ftm_quaddec_disable()
120 	struct ftm_quaddec *ftm = counter_priv(counter);  in ftm_quaddec_get_prescaler()  local
123 	ftm_read(ftm, FTM_SC, &scflags);  in ftm_quaddec_get_prescaler()
133 	struct ftm_quaddec *ftm = counter_priv(counter);  in ftm_quaddec_set_prescaler()  local
135 	mutex_lock(&ftm->ftm_quaddec_mutex);  in ftm_quaddec_set_prescaler()
137 	ftm_clear_write_protection(ftm);  in ftm_quaddec_set_prescaler()
138 	FTM_FIELD_UPDATE(ftm, FTM_SC, FTM_SC_PS_MASK, cnt_mode);  in ftm_quaddec_set_prescaler()
139 	ftm_set_write_protection(ftm);  in ftm_quaddec_set_prescaler()
142 	ftm_reset_counter(ftm);  in ftm_quaddec_set_prescaler()
144 	mutex_unlock(&ftm->ftm_quaddec_mutex);  in ftm_quaddec_set_prescaler()
164 	struct ftm_quaddec *const ftm = counter_priv(counter);  in ftm_quaddec_count_read()  local
167 	ftm_read(ftm, FTM_CNT, &cntval);  in ftm_quaddec_count_read()
178 	struct ftm_quaddec *const ftm = counter_priv(counter);  in ftm_quaddec_count_write()  local
181 		dev_warn(&ftm->pdev->dev, "Can only accept '0' as new counter value\n");  in ftm_quaddec_count_write()
182 		return -EINVAL;  in ftm_quaddec_count_write()
185 	ftm_reset_counter(ftm);  in ftm_quaddec_count_write()
262 	struct ftm_quaddec *ftm;  in ftm_quaddec_probe()  local
264 	struct device_node *node = pdev->dev.of_node;  in ftm_quaddec_probe()
268 	counter = devm_counter_alloc(&pdev->dev, sizeof(*ftm));  in ftm_quaddec_probe()
270 		return -ENOMEM;  in ftm_quaddec_probe()
271 	ftm = counter_priv(counter);  in ftm_quaddec_probe()
275 		dev_err(&pdev->dev, "Failed to get memory region\n");  in ftm_quaddec_probe()
276 		return -ENODEV;  in ftm_quaddec_probe()
279 	ftm->pdev = pdev;  in ftm_quaddec_probe()
280 	ftm->big_endian = of_property_read_bool(node, "big-endian");  in ftm_quaddec_probe()
281 	ftm->ftm_base = devm_ioremap(&pdev->dev, io->start, resource_size(io));  in ftm_quaddec_probe()
283 	if (!ftm->ftm_base) {  in ftm_quaddec_probe()
284 		dev_err(&pdev->dev, "Failed to map memory region\n");  in ftm_quaddec_probe()
285 		return -EINVAL;  in ftm_quaddec_probe()
287 	counter->name = dev_name(&pdev->dev);  in ftm_quaddec_probe()
288 	counter->parent = &pdev->dev;  in ftm_quaddec_probe()
289 	counter->ops = &ftm_quaddec_cnt_ops;  in ftm_quaddec_probe()
290 	counter->counts = &ftm_quaddec_counts;  in ftm_quaddec_probe()
291 	counter->num_counts = 1;  in ftm_quaddec_probe()
292 	counter->signals = ftm_quaddec_signals;  in ftm_quaddec_probe()
293 	counter->num_signals = ARRAY_SIZE(ftm_quaddec_signals);  in ftm_quaddec_probe()
295 	mutex_init(&ftm->ftm_quaddec_mutex);  in ftm_quaddec_probe()
297 	ftm_quaddec_init(ftm);  in ftm_quaddec_probe()
299 	ret = devm_add_action_or_reset(&pdev->dev, ftm_quaddec_disable, ftm);  in ftm_quaddec_probe()
303 	ret = devm_counter_add(&pdev->dev, counter);  in ftm_quaddec_probe()
305 		return dev_err_probe(&pdev->dev, ret, "Failed to add counter\n");  in ftm_quaddec_probe()
311 	{ .compatible = "fsl,ftm-quaddec" },
318 		.name = "ftm-quaddec",
326 MODULE_DESCRIPTION("Flex Timer Module Quadrature decoder");