xref: /openbmc/linux/drivers/ata/sata_gemini.c (revision da1d9caf)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Cortina Systems Gemini SATA bridge add-on to Faraday FTIDE010
4  * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
5  */
6 
7 #include <linux/init.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/bitops.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/regmap.h>
13 #include <linux/delay.h>
14 #include <linux/reset.h>
15 #include <linux/of_address.h>
16 #include <linux/of_device.h>
17 #include <linux/clk.h>
18 #include <linux/io.h>
19 #include <linux/pinctrl/consumer.h>
20 #include "sata_gemini.h"
21 
22 #define DRV_NAME "gemini_sata_bridge"
23 
24 /**
25  * struct sata_gemini - a state container for a Gemini SATA bridge
26  * @dev: the containing device
27  * @base: remapped I/O memory base
28  * @muxmode: the current muxing mode
29  * @ide_pins: if the device is using the plain IDE interface pins
30  * @sata_bridge: if the device enables the SATA bridge
31  * @sata0_reset: SATA0 reset handler
32  * @sata1_reset: SATA1 reset handler
33  * @sata0_pclk: SATA0 PCLK handler
34  * @sata1_pclk: SATA1 PCLK handler
35  */
36 struct sata_gemini {
37 	struct device *dev;
38 	void __iomem *base;
39 	enum gemini_muxmode muxmode;
40 	bool ide_pins;
41 	bool sata_bridge;
42 	struct reset_control *sata0_reset;
43 	struct reset_control *sata1_reset;
44 	struct clk *sata0_pclk;
45 	struct clk *sata1_pclk;
46 };
47 
48 /* Miscellaneous Control Register */
49 #define GEMINI_GLOBAL_MISC_CTRL		0x30
50 /*
51  * Values of IDE IOMUX bits in the misc control register
52  *
53  * Bits 26:24 are "IDE IO Select", which decides what SATA
54  * adapters are connected to which of the two IDE/ATA
55  * controllers in the Gemini. We can connect the two IDE blocks
56  * to one SATA adapter each, both acting as master, or one IDE
57  * blocks to two SATA adapters so the IDE block can act in a
58  * master/slave configuration.
59  *
60  * We also bring out different blocks on the actual IDE
61  * pins (not SATA pins) if (and only if) these are muxed in.
62  *
63  * 111-100 - Reserved
64  * Mode 0: 000 - ata0 master <-> sata0
65  *               ata1 master <-> sata1
66  *               ata0 slave interface brought out on IDE pads
67  * Mode 1: 001 - ata0 master <-> sata0
68  *               ata1 master <-> sata1
69  *               ata1 slave interface brought out on IDE pads
70  * Mode 2: 010 - ata1 master <-> sata1
71  *               ata1 slave  <-> sata0
72  *               ata0 master and slave interfaces brought out
73  *                    on IDE pads
74  * Mode 3: 011 - ata0 master <-> sata0
75  *               ata1 slave  <-> sata1
76  *               ata1 master and slave interfaces brought out
77  *                    on IDE pads
78  */
79 #define GEMINI_IDE_IOMUX_MASK			(7 << 24)
80 #define GEMINI_IDE_IOMUX_MODE0			(0 << 24)
81 #define GEMINI_IDE_IOMUX_MODE1			(1 << 24)
82 #define GEMINI_IDE_IOMUX_MODE2			(2 << 24)
83 #define GEMINI_IDE_IOMUX_MODE3			(3 << 24)
84 #define GEMINI_IDE_IOMUX_SHIFT			(24)
85 
86 /*
87  * Registers directly controlling the PATA<->SATA adapters
88  */
89 #define GEMINI_SATA_ID				0x00
90 #define GEMINI_SATA_PHY_ID			0x04
91 #define GEMINI_SATA0_STATUS			0x08
92 #define GEMINI_SATA1_STATUS			0x0c
93 #define GEMINI_SATA0_CTRL			0x18
94 #define GEMINI_SATA1_CTRL			0x1c
95 
96 #define GEMINI_SATA_STATUS_BIST_DONE		BIT(5)
97 #define GEMINI_SATA_STATUS_BIST_OK		BIT(4)
98 #define GEMINI_SATA_STATUS_PHY_READY		BIT(0)
99 
100 #define GEMINI_SATA_CTRL_PHY_BIST_EN		BIT(14)
101 #define GEMINI_SATA_CTRL_PHY_FORCE_IDLE		BIT(13)
102 #define GEMINI_SATA_CTRL_PHY_FORCE_READY	BIT(12)
103 #define GEMINI_SATA_CTRL_PHY_AFE_LOOP_EN	BIT(10)
104 #define GEMINI_SATA_CTRL_PHY_DIG_LOOP_EN	BIT(9)
105 #define GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN	BIT(4)
106 #define GEMINI_SATA_CTRL_ATAPI_EN		BIT(3)
107 #define GEMINI_SATA_CTRL_BUS_WITH_20		BIT(2)
108 #define GEMINI_SATA_CTRL_SLAVE_EN		BIT(1)
109 #define GEMINI_SATA_CTRL_EN			BIT(0)
110 
111 /*
112  * There is only ever one instance of this bridge on a system,
113  * so create a singleton so that the FTIDE010 instances can grab
114  * a reference to it.
115  */
116 static struct sata_gemini *sg_singleton;
117 
118 struct sata_gemini *gemini_sata_bridge_get(void)
119 {
120 	if (sg_singleton)
121 		return sg_singleton;
122 	return ERR_PTR(-EPROBE_DEFER);
123 }
124 EXPORT_SYMBOL(gemini_sata_bridge_get);
125 
126 bool gemini_sata_bridge_enabled(struct sata_gemini *sg, bool is_ata1)
127 {
128 	if (!sg->sata_bridge)
129 		return false;
130 	/*
131 	 * In muxmode 2 and 3 one of the ATA controllers is
132 	 * actually not connected to any SATA bridge.
133 	 */
134 	if ((sg->muxmode == GEMINI_MUXMODE_2) &&
135 	    !is_ata1)
136 		return false;
137 	if ((sg->muxmode == GEMINI_MUXMODE_3) &&
138 	    is_ata1)
139 		return false;
140 
141 	return true;
142 }
143 EXPORT_SYMBOL(gemini_sata_bridge_enabled);
144 
145 enum gemini_muxmode gemini_sata_get_muxmode(struct sata_gemini *sg)
146 {
147 	return sg->muxmode;
148 }
149 EXPORT_SYMBOL(gemini_sata_get_muxmode);
150 
151 static int gemini_sata_setup_bridge(struct sata_gemini *sg,
152 				    unsigned int bridge)
153 {
154 	unsigned long timeout = jiffies + (HZ * 1);
155 	bool bridge_online;
156 	u32 val;
157 
158 	if (bridge == 0) {
159 		val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN | GEMINI_SATA_CTRL_EN;
160 		/* SATA0 slave mode is only used in muxmode 2 */
161 		if (sg->muxmode == GEMINI_MUXMODE_2)
162 			val |= GEMINI_SATA_CTRL_SLAVE_EN;
163 		writel(val, sg->base + GEMINI_SATA0_CTRL);
164 	} else {
165 		val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN | GEMINI_SATA_CTRL_EN;
166 		/* SATA1 slave mode is only used in muxmode 3 */
167 		if (sg->muxmode == GEMINI_MUXMODE_3)
168 			val |= GEMINI_SATA_CTRL_SLAVE_EN;
169 		writel(val, sg->base + GEMINI_SATA1_CTRL);
170 	}
171 
172 	/* Vendor code waits 10 ms here */
173 	msleep(10);
174 
175 	/* Wait for PHY to become ready */
176 	do {
177 		msleep(100);
178 
179 		if (bridge == 0)
180 			val = readl(sg->base + GEMINI_SATA0_STATUS);
181 		else
182 			val = readl(sg->base + GEMINI_SATA1_STATUS);
183 		if (val & GEMINI_SATA_STATUS_PHY_READY)
184 			break;
185 	} while (time_before(jiffies, timeout));
186 
187 	bridge_online = !!(val & GEMINI_SATA_STATUS_PHY_READY);
188 
189 	dev_info(sg->dev, "SATA%d PHY %s\n", bridge,
190 		 bridge_online ? "ready" : "not ready");
191 
192 	return bridge_online ? 0: -ENODEV;
193 }
194 
195 int gemini_sata_start_bridge(struct sata_gemini *sg, unsigned int bridge)
196 {
197 	struct clk *pclk;
198 	int ret;
199 
200 	if (bridge == 0)
201 		pclk = sg->sata0_pclk;
202 	else
203 		pclk = sg->sata1_pclk;
204 	clk_enable(pclk);
205 	msleep(10);
206 
207 	/* Do not keep clocking a bridge that is not online */
208 	ret = gemini_sata_setup_bridge(sg, bridge);
209 	if (ret)
210 		clk_disable(pclk);
211 
212 	return ret;
213 }
214 EXPORT_SYMBOL(gemini_sata_start_bridge);
215 
216 void gemini_sata_stop_bridge(struct sata_gemini *sg, unsigned int bridge)
217 {
218 	if (bridge == 0)
219 		clk_disable(sg->sata0_pclk);
220 	else if (bridge == 1)
221 		clk_disable(sg->sata1_pclk);
222 }
223 EXPORT_SYMBOL(gemini_sata_stop_bridge);
224 
225 int gemini_sata_reset_bridge(struct sata_gemini *sg,
226 			     unsigned int bridge)
227 {
228 	if (bridge == 0)
229 		reset_control_reset(sg->sata0_reset);
230 	else
231 		reset_control_reset(sg->sata1_reset);
232 	msleep(10);
233 	return gemini_sata_setup_bridge(sg, bridge);
234 }
235 EXPORT_SYMBOL(gemini_sata_reset_bridge);
236 
237 static int gemini_sata_bridge_init(struct sata_gemini *sg)
238 {
239 	struct device *dev = sg->dev;
240 	u32 sata_id, sata_phy_id;
241 	int ret;
242 
243 	sg->sata0_pclk = devm_clk_get(dev, "SATA0_PCLK");
244 	if (IS_ERR(sg->sata0_pclk)) {
245 		dev_err(dev, "no SATA0 PCLK");
246 		return -ENODEV;
247 	}
248 	sg->sata1_pclk = devm_clk_get(dev, "SATA1_PCLK");
249 	if (IS_ERR(sg->sata1_pclk)) {
250 		dev_err(dev, "no SATA1 PCLK");
251 		return -ENODEV;
252 	}
253 
254 	ret = clk_prepare_enable(sg->sata0_pclk);
255 	if (ret) {
256 		dev_err(dev, "failed to enable SATA0 PCLK\n");
257 		return ret;
258 	}
259 	ret = clk_prepare_enable(sg->sata1_pclk);
260 	if (ret) {
261 		dev_err(dev, "failed to enable SATA1 PCLK\n");
262 		clk_disable_unprepare(sg->sata0_pclk);
263 		return ret;
264 	}
265 
266 	sg->sata0_reset = devm_reset_control_get_exclusive(dev, "sata0");
267 	if (IS_ERR(sg->sata0_reset)) {
268 		dev_err(dev, "no SATA0 reset controller\n");
269 		clk_disable_unprepare(sg->sata1_pclk);
270 		clk_disable_unprepare(sg->sata0_pclk);
271 		return PTR_ERR(sg->sata0_reset);
272 	}
273 	sg->sata1_reset = devm_reset_control_get_exclusive(dev, "sata1");
274 	if (IS_ERR(sg->sata1_reset)) {
275 		dev_err(dev, "no SATA1 reset controller\n");
276 		clk_disable_unprepare(sg->sata1_pclk);
277 		clk_disable_unprepare(sg->sata0_pclk);
278 		return PTR_ERR(sg->sata1_reset);
279 	}
280 
281 	sata_id = readl(sg->base + GEMINI_SATA_ID);
282 	sata_phy_id = readl(sg->base + GEMINI_SATA_PHY_ID);
283 	sg->sata_bridge = true;
284 	clk_disable(sg->sata0_pclk);
285 	clk_disable(sg->sata1_pclk);
286 
287 	dev_info(dev, "SATA ID %08x, PHY ID: %08x\n", sata_id, sata_phy_id);
288 
289 	return 0;
290 }
291 
292 static int gemini_setup_ide_pins(struct device *dev)
293 {
294 	struct pinctrl *p;
295 	struct pinctrl_state *ide_state;
296 	int ret;
297 
298 	p = devm_pinctrl_get(dev);
299 	if (IS_ERR(p))
300 		return PTR_ERR(p);
301 
302 	ide_state = pinctrl_lookup_state(p, "ide");
303 	if (IS_ERR(ide_state))
304 		return PTR_ERR(ide_state);
305 
306 	ret = pinctrl_select_state(p, ide_state);
307 	if (ret) {
308 		dev_err(dev, "could not select IDE state\n");
309 		return ret;
310 	}
311 
312 	return 0;
313 }
314 
315 static int gemini_sata_probe(struct platform_device *pdev)
316 {
317 	struct device *dev = &pdev->dev;
318 	struct device_node *np = dev->of_node;
319 	struct sata_gemini *sg;
320 	struct regmap *map;
321 	enum gemini_muxmode muxmode;
322 	u32 gmode;
323 	u32 gmask;
324 	int ret;
325 
326 	sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
327 	if (!sg)
328 		return -ENOMEM;
329 	sg->dev = dev;
330 
331 	sg->base = devm_platform_ioremap_resource(pdev, 0);
332 	if (IS_ERR(sg->base))
333 		return PTR_ERR(sg->base);
334 
335 	map = syscon_regmap_lookup_by_phandle(np, "syscon");
336 	if (IS_ERR(map)) {
337 		dev_err(dev, "no global syscon\n");
338 		return PTR_ERR(map);
339 	}
340 
341 	/* Set up the SATA bridge if need be */
342 	if (of_property_read_bool(np, "cortina,gemini-enable-sata-bridge")) {
343 		ret = gemini_sata_bridge_init(sg);
344 		if (ret)
345 			return ret;
346 	}
347 
348 	if (of_property_read_bool(np, "cortina,gemini-enable-ide-pins"))
349 		sg->ide_pins = true;
350 
351 	if (!sg->sata_bridge && !sg->ide_pins) {
352 		dev_err(dev, "neither SATA bridge or IDE output enabled\n");
353 		ret = -EINVAL;
354 		goto out_unprep_clk;
355 	}
356 
357 	ret = of_property_read_u32(np, "cortina,gemini-ata-muxmode", &muxmode);
358 	if (ret) {
359 		dev_err(dev, "could not parse ATA muxmode\n");
360 		goto out_unprep_clk;
361 	}
362 	if (muxmode > GEMINI_MUXMODE_3) {
363 		dev_err(dev, "illegal muxmode %d\n", muxmode);
364 		ret = -EINVAL;
365 		goto out_unprep_clk;
366 	}
367 	sg->muxmode = muxmode;
368 	gmask = GEMINI_IDE_IOMUX_MASK;
369 	gmode = (muxmode << GEMINI_IDE_IOMUX_SHIFT);
370 
371 	ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, gmask, gmode);
372 	if (ret) {
373 		dev_err(dev, "unable to set up IDE muxing\n");
374 		ret = -ENODEV;
375 		goto out_unprep_clk;
376 	}
377 
378 	/*
379 	 * Route out the IDE pins if desired.
380 	 * This is done by looking up a special pin control state called
381 	 * "ide" that will route out the IDE pins.
382 	 */
383 	if (sg->ide_pins) {
384 		ret = gemini_setup_ide_pins(dev);
385 		if (ret)
386 			return ret;
387 	}
388 
389 	dev_info(dev, "set up the Gemini IDE/SATA nexus\n");
390 	platform_set_drvdata(pdev, sg);
391 	sg_singleton = sg;
392 
393 	return 0;
394 
395 out_unprep_clk:
396 	if (sg->sata_bridge) {
397 		clk_unprepare(sg->sata1_pclk);
398 		clk_unprepare(sg->sata0_pclk);
399 	}
400 	return ret;
401 }
402 
403 static int gemini_sata_remove(struct platform_device *pdev)
404 {
405 	struct sata_gemini *sg = platform_get_drvdata(pdev);
406 
407 	if (sg->sata_bridge) {
408 		clk_unprepare(sg->sata1_pclk);
409 		clk_unprepare(sg->sata0_pclk);
410 	}
411 	sg_singleton = NULL;
412 
413 	return 0;
414 }
415 
416 static const struct of_device_id gemini_sata_of_match[] = {
417 	{ .compatible = "cortina,gemini-sata-bridge", },
418 	{ /* sentinel */ }
419 };
420 
421 static struct platform_driver gemini_sata_driver = {
422 	.driver = {
423 		.name = DRV_NAME,
424 		.of_match_table = of_match_ptr(gemini_sata_of_match),
425 	},
426 	.probe = gemini_sata_probe,
427 	.remove = gemini_sata_remove,
428 };
429 module_platform_driver(gemini_sata_driver);
430 
431 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
432 MODULE_LICENSE("GPL");
433 MODULE_ALIAS("platform:" DRV_NAME);
434