2  * Atmel AT91 SAM9 & SAMA5 SoCs reset code
20 #include <linux/reset-controller.h>
26 #include <dt-bindings/reset/sama7g5-reset.h>
28 #define AT91_RSTC_CR	0x00		/* Reset Controller Control Register */
29 #define AT91_RSTC_PROCRST	BIT(0)		/* Processor Reset */
30 #define AT91_RSTC_PERRST	BIT(2)		/* Peripheral Reset */
31 #define AT91_RSTC_EXTRST	BIT(3)		/* External Reset */
34 #define AT91_RSTC_SR	0x04		/* Reset Controller Status Register */
35 #define AT91_RSTC_URSTS		BIT(0)		/* User Reset Status */
36 #define AT91_RSTC_RSTTYP	GENMASK(10, 8)	/* Reset Type */
38 #define AT91_RSTC_SRCMP		BIT(17)		/* Software Reset Command in Progress */
40 #define AT91_RSTC_MR	0x08		/* Reset Controller Mode Register */
41 #define AT91_RSTC_URSTEN	BIT(0)		/* User Reset Enable */
42 #define AT91_RSTC_URSTASYNC	BIT(2)		/* User Reset Asynchronous Control */
43 #define AT91_RSTC_URSTIEN	BIT(4)		/* User Reset Interrupt Enable */
44 #define AT91_RSTC_ERSTL		GENMASK(11, 8)	/* External Reset Length */
47  * enum reset_type - reset types
48  * @RESET_TYPE_GENERAL:		first power-up reset
51  * @RESET_TYPE_SOFTWARE:	processor reset required by software
55  * @RESET_TYPE_ULP2:		ULP2 reset
69  * struct at91_reset - AT91 reset specific data structure
70  * @rstc_base:		base address for system reset
72  * @dev_base:		base address for devices reset
74  * @data:		platform specific reset data
75  * @rcdev:		reset controller device
76  * @lock:		lock for devices reset register access
77  * @nb:			reset notifier block
78  * @args:		SoC specific system reset arguments
97  * struct at91_reset_data - AT91 reset data
98  * @reset_args:			SoC specific system reset arguments
100  * @device_reset_min_id:	min id for device reset
101  * @device_reset_max_id:	max id for device reset
112 * reset register it can be left driving the data bus and
118 	struct at91_reset *reset = container_of(this, struct at91_reset, nb);  in at91_reset()  local
135 		/* Reset CPU */  in at91_reset()
140 		: "r" (reset->ramc_base[0]),  in at91_reset()
141 		  "r" (reset->ramc_base[1]),  in at91_reset()
142 		  "r" (reset->rstc_base),  in at91_reset()
145 		  "r" (reset->data->reset_args),  in at91_reset()
146 		  "r" (reset->ramc_lpr)  in at91_reset()
152 static const char *at91_reset_reason(struct at91_reset *reset)  in at91_reset_reason()  argument
154 	u32 reg = readl(reset->rstc_base + AT91_RSTC_SR);  in at91_reset_reason()
194 	struct at91_reset *reset = platform_get_drvdata(pdev);  in power_on_reason_show()  local
196 	return sprintf(buf, "%s\n", at91_reset_reason(reset));  in power_on_reason_show()
259 	struct at91_reset *reset = to_at91_reset(rcdev);  in at91_reset_update()  local
263 	spin_lock_irqsave(&reset->lock, flags);  in at91_reset_update()
264 	val = readl_relaxed(reset->dev_base);  in at91_reset_update()
269 	writel_relaxed(val, reset->dev_base);  in at91_reset_update()
270 	spin_unlock_irqrestore(&reset->lock, flags);  in at91_reset_update()
290 	struct at91_reset *reset = to_at91_reset(rcdev);  in at91_reset_dev_status()  local
293 	val = readl_relaxed(reset->dev_base);  in at91_reset_dev_status()
307 	struct at91_reset *reset = to_at91_reset(rcdev);  in at91_reset_of_xlate()  local
309 	if (!reset->data->n_device_reset ||  in at91_reset_of_xlate()
310 	    (reset_spec->args[0] < reset->data->device_reset_min_id ||  in at91_reset_of_xlate()
311 	     reset_spec->args[0] > reset->data->device_reset_max_id))  in at91_reset_of_xlate()
317 static int at91_rcdev_init(struct at91_reset *reset,  in at91_rcdev_init()  argument
320 	if (!reset->data->n_device_reset)  in at91_rcdev_init()
323 	reset->dev_base = devm_of_iomap(&pdev->dev, pdev->dev.of_node, 1,  in at91_rcdev_init()
325 	if (IS_ERR(reset->dev_base))  in at91_rcdev_init()
328 	spin_lock_init(&reset->lock);  in at91_rcdev_init()
329 	reset->rcdev.ops = &at91_reset_ops;  in at91_rcdev_init()
330 	reset->rcdev.owner = THIS_MODULE;  in at91_rcdev_init()
331 	reset->rcdev.of_node = pdev->dev.of_node;  in at91_rcdev_init()
332 	reset->rcdev.nr_resets = reset->data->n_device_reset;  in at91_rcdev_init()
333 	reset->rcdev.of_reset_n_cells = 1;  in at91_rcdev_init()
334 	reset->rcdev.of_xlate = at91_reset_of_xlate;  in at91_rcdev_init()
336 	return devm_reset_controller_register(&pdev->dev, &reset->rcdev);  in at91_rcdev_init()
342 	struct at91_reset *reset;  in at91_reset_probe()  local
346 	reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL);  in at91_reset_probe()
347 	if (!reset)  in at91_reset_probe()
350 	reset->rstc_base = devm_of_iomap(&pdev->dev, pdev->dev.of_node, 0, NULL);  in at91_reset_probe()
351 	if (IS_ERR(reset->rstc_base)) {  in at91_reset_probe()
352 		dev_err(&pdev->dev, "Could not map reset controller address\n");  in at91_reset_probe()
359 			reset->ramc_lpr = (u32)match->data;  in at91_reset_probe()
360 			reset->ramc_base[idx] = devm_of_iomap(&pdev->dev, np, 0, NULL);  in at91_reset_probe()
361 			if (IS_ERR(reset->ramc_base[idx])) {  in at91_reset_probe()
370 	reset->data = device_get_match_data(&pdev->dev);  in at91_reset_probe()
371 	if (!reset->data)  in at91_reset_probe()
374 	reset->nb.notifier_call = at91_reset;  in at91_reset_probe()
375 	reset->nb.priority = 192;  in at91_reset_probe()
377 	reset->sclk = devm_clk_get(&pdev->dev, NULL);  in at91_reset_probe()
378 	if (IS_ERR(reset->sclk))  in at91_reset_probe()
379 		return PTR_ERR(reset->sclk);  in at91_reset_probe()
381 	ret = clk_prepare_enable(reset->sclk);  in at91_reset_probe()
387 	platform_set_drvdata(pdev, reset);  in at91_reset_probe()
389 	ret = at91_rcdev_init(reset, pdev);  in at91_reset_probe()
394 		u32 val = readl(reset->rstc_base + AT91_RSTC_MR);  in at91_reset_probe()
397 		       reset->rstc_base + AT91_RSTC_MR);  in at91_reset_probe()
400 	ret = register_restart_handler(&reset->nb);  in at91_reset_probe()
410 	dev_info(&pdev->dev, "Starting after %s\n", at91_reset_reason(reset));  in at91_reset_probe()
415 	clk_disable_unprepare(reset->sclk);  in at91_reset_probe()
421 	struct at91_reset *reset = platform_get_drvdata(pdev);  in at91_reset_remove()  local
423 	unregister_restart_handler(&reset->nb);  in at91_reset_remove()
424 	clk_disable_unprepare(reset->sclk);  in at91_reset_remove()
431 		.name = "at91-reset",
438 MODULE_DESCRIPTION("Reset driver for Atmel SoCs");