xref: /openbmc/linux/drivers/ata/sata_gemini.c (revision 9aa2cba7)
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.h>
16 #include <linux/clk.h>
17 #include <linux/io.h>
18 #include <linux/pinctrl/consumer.h>
19 #include "sata_gemini.h"
20 
21 #define DRV_NAME "gemini_sata_bridge"
22 
23 /**
24  * struct sata_gemini - a state container for a Gemini SATA bridge
25  * @dev: the containing device
26  * @base: remapped I/O memory base
27  * @muxmode: the current muxing mode
28  * @ide_pins: if the device is using the plain IDE interface pins
29  * @sata_bridge: if the device enables the SATA bridge
30  * @sata0_reset: SATA0 reset handler
31  * @sata1_reset: SATA1 reset handler
32  * @sata0_pclk: SATA0 PCLK handler
33  * @sata1_pclk: SATA1 PCLK handler
34  */
35 struct sata_gemini {
36 	struct device *dev;
37 	void __iomem *base;
38 	enum gemini_muxmode muxmode;
39 	bool ide_pins;
40 	bool sata_bridge;
41 	struct reset_control *sata0_reset;
42 	struct reset_control *sata1_reset;
43 	struct clk *sata0_pclk;
44 	struct clk *sata1_pclk;
45 };
46 
47 /* Miscellaneous Control Register */
48 #define GEMINI_GLOBAL_MISC_CTRL		0x30
49 /*
50  * Values of IDE IOMUX bits in the misc control register
51  *
52  * Bits 26:24 are "IDE IO Select", which decides what SATA
53  * adapters are connected to which of the two IDE/ATA
54  * controllers in the Gemini. We can connect the two IDE blocks
55  * to one SATA adapter each, both acting as master, or one IDE
56  * blocks to two SATA adapters so the IDE block can act in a
57  * master/slave configuration.
58  *
59  * We also bring out different blocks on the actual IDE
60  * pins (not SATA pins) if (and only if) these are muxed in.
61  *
62  * 111-100 - Reserved
63  * Mode 0: 000 - ata0 master <-> sata0
64  *               ata1 master <-> sata1
65  *               ata0 slave interface brought out on IDE pads
66  * Mode 1: 001 - ata0 master <-> sata0
67  *               ata1 master <-> sata1
68  *               ata1 slave interface brought out on IDE pads
69  * Mode 2: 010 - ata1 master <-> sata1
70  *               ata1 slave  <-> sata0
71  *               ata0 master and slave interfaces brought out
72  *                    on IDE pads
73  * Mode 3: 011 - ata0 master <-> sata0
74  *               ata1 slave  <-> sata1
75  *               ata1 master and slave interfaces brought out
76  *                    on IDE pads
77  */
78 #define GEMINI_IDE_IOMUX_MASK			(7 << 24)
79 #define GEMINI_IDE_IOMUX_MODE0			(0 << 24)
80 #define GEMINI_IDE_IOMUX_MODE1			(1 << 24)
81 #define GEMINI_IDE_IOMUX_MODE2			(2 << 24)
82 #define GEMINI_IDE_IOMUX_MODE3			(3 << 24)
83 #define GEMINI_IDE_IOMUX_SHIFT			(24)
84 
85 /*
86  * Registers directly controlling the PATA<->SATA adapters
87  */
88 #define GEMINI_SATA_ID				0x00
89 #define GEMINI_SATA_PHY_ID			0x04
90 #define GEMINI_SATA0_STATUS			0x08
91 #define GEMINI_SATA1_STATUS			0x0c
92 #define GEMINI_SATA0_CTRL			0x18
93 #define GEMINI_SATA1_CTRL			0x1c
94 
95 #define GEMINI_SATA_STATUS_BIST_DONE		BIT(5)
96 #define GEMINI_SATA_STATUS_BIST_OK		BIT(4)
97 #define GEMINI_SATA_STATUS_PHY_READY		BIT(0)
98 
99 #define GEMINI_SATA_CTRL_PHY_BIST_EN		BIT(14)
100 #define GEMINI_SATA_CTRL_PHY_FORCE_IDLE		BIT(13)
101 #define GEMINI_SATA_CTRL_PHY_FORCE_READY	BIT(12)
102 #define GEMINI_SATA_CTRL_PHY_AFE_LOOP_EN	BIT(10)
103 #define GEMINI_SATA_CTRL_PHY_DIG_LOOP_EN	BIT(9)
104 #define GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN	BIT(4)
105 #define GEMINI_SATA_CTRL_ATAPI_EN		BIT(3)
106 #define GEMINI_SATA_CTRL_BUS_WITH_20		BIT(2)
107 #define GEMINI_SATA_CTRL_SLAVE_EN		BIT(1)
108 #define GEMINI_SATA_CTRL_EN			BIT(0)
109 
110 /*
111  * There is only ever one instance of this bridge on a system,
112  * so create a singleton so that the FTIDE010 instances can grab
113  * a reference to it.
114  */
115 static struct sata_gemini *sg_singleton;
116 
117 struct sata_gemini *gemini_sata_bridge_get(void)
118 {
119 	if (sg_singleton)
120 		return sg_singleton;
121 	return ERR_PTR(-EPROBE_DEFER);
122 }
123 EXPORT_SYMBOL(gemini_sata_bridge_get);
124 
125 bool gemini_sata_bridge_enabled(struct sata_gemini *sg, bool is_ata1)
126 {
127 	if (!sg->sata_bridge)
128 		return false;
129 	/*
130 	 * In muxmode 2 and 3 one of the ATA controllers is
131 	 * actually not connected to any SATA bridge.
132 	 */
133 	if ((sg->muxmode == GEMINI_MUXMODE_2) &&
134 	    !is_ata1)
135 		return false;
136 	if ((sg->muxmode == GEMINI_MUXMODE_3) &&
137 	    is_ata1)
138 		return false;
139 
140 	return true;
141 }
142 EXPORT_SYMBOL(gemini_sata_bridge_enabled);
143 
144 enum gemini_muxmode gemini_sata_get_muxmode(struct sata_gemini *sg)
145 {
146 	return sg->muxmode;
147 }
148 EXPORT_SYMBOL(gemini_sata_get_muxmode);
149 
150 static int gemini_sata_setup_bridge(struct sata_gemini *sg,
151 				    unsigned int bridge)
152 {
153 	unsigned long timeout = jiffies + (HZ * 1);
154 	bool bridge_online;
155 	u32 val;
156 
157 	if (bridge == 0) {
158 		val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN | GEMINI_SATA_CTRL_EN;
159 		/* SATA0 slave mode is only used in muxmode 2 */
160 		if (sg->muxmode == GEMINI_MUXMODE_2)
161 			val |= GEMINI_SATA_CTRL_SLAVE_EN;
162 		writel(val, sg->base + GEMINI_SATA0_CTRL);
163 	} else {
164 		val = GEMINI_SATA_CTRL_HOTPLUG_DETECT_EN | GEMINI_SATA_CTRL_EN;
165 		/* SATA1 slave mode is only used in muxmode 3 */
166 		if (sg->muxmode == GEMINI_MUXMODE_3)
167 			val |= GEMINI_SATA_CTRL_SLAVE_EN;
168 		writel(val, sg->base + GEMINI_SATA1_CTRL);
169 	}
170 
171 	/* Vendor code waits 10 ms here */
172 	msleep(10);
173 
174 	/* Wait for PHY to become ready */
175 	do {
176 		msleep(100);
177 
178 		if (bridge == 0)
179 			val = readl(sg->base + GEMINI_SATA0_STATUS);
180 		else
181 			val = readl(sg->base + GEMINI_SATA1_STATUS);
182 		if (val & GEMINI_SATA_STATUS_PHY_READY)
183 			break;
184 	} while (time_before(jiffies, timeout));
185 
186 	bridge_online = !!(val & GEMINI_SATA_STATUS_PHY_READY);
187 
188 	dev_info(sg->dev, "SATA%d PHY %s\n", bridge,
189 		 bridge_online ? "ready" : "not ready");
190 
191 	return bridge_online ? 0: -ENODEV;
192 }
193 
194 int gemini_sata_start_bridge(struct sata_gemini *sg, unsigned int bridge)
195 {
196 	struct clk *pclk;
197 	int ret;
198 
199 	if (bridge == 0)
200 		pclk = sg->sata0_pclk;
201 	else
202 		pclk = sg->sata1_pclk;
203 	clk_enable(pclk);
204 	msleep(10);
205 
206 	/* Do not keep clocking a bridge that is not online */
207 	ret = gemini_sata_setup_bridge(sg, bridge);
208 	if (ret)
209 		clk_disable(pclk);
210 
211 	return ret;
212 }
213 EXPORT_SYMBOL(gemini_sata_start_bridge);
214 
215 void gemini_sata_stop_bridge(struct sata_gemini *sg, unsigned int bridge)
216 {
217 	if (bridge == 0)
218 		clk_disable(sg->sata0_pclk);
219 	else if (bridge == 1)
220 		clk_disable(sg->sata1_pclk);
221 }
222 EXPORT_SYMBOL(gemini_sata_stop_bridge);
223 
224 int gemini_sata_reset_bridge(struct sata_gemini *sg,
225 			     unsigned int bridge)
226 {
227 	if (bridge == 0)
228 		reset_control_reset(sg->sata0_reset);
229 	else
230 		reset_control_reset(sg->sata1_reset);
231 	msleep(10);
232 	return gemini_sata_setup_bridge(sg, bridge);
233 }
234 EXPORT_SYMBOL(gemini_sata_reset_bridge);
235 
236 static int gemini_sata_bridge_init(struct sata_gemini *sg)
237 {
238 	struct device *dev = sg->dev;
239 	u32 sata_id, sata_phy_id;
240 	int ret;
241 
242 	sg->sata0_pclk = devm_clk_get(dev, "SATA0_PCLK");
243 	if (IS_ERR(sg->sata0_pclk)) {
244 		dev_err(dev, "no SATA0 PCLK");
245 		return -ENODEV;
246 	}
247 	sg->sata1_pclk = devm_clk_get(dev, "SATA1_PCLK");
248 	if (IS_ERR(sg->sata1_pclk)) {
249 		dev_err(dev, "no SATA1 PCLK");
250 		return -ENODEV;
251 	}
252 
253 	ret = clk_prepare_enable(sg->sata0_pclk);
254 	if (ret) {
255 		dev_err(dev, "failed to enable SATA0 PCLK\n");
256 		return ret;
257 	}
258 	ret = clk_prepare_enable(sg->sata1_pclk);
259 	if (ret) {
260 		dev_err(dev, "failed to enable SATA1 PCLK\n");
261 		clk_disable_unprepare(sg->sata0_pclk);
262 		return ret;
263 	}
264 
265 	sg->sata0_reset = devm_reset_control_get_exclusive(dev, "sata0");
266 	if (IS_ERR(sg->sata0_reset)) {
267 		dev_err(dev, "no SATA0 reset controller\n");
268 		clk_disable_unprepare(sg->sata1_pclk);
269 		clk_disable_unprepare(sg->sata0_pclk);
270 		return PTR_ERR(sg->sata0_reset);
271 	}
272 	sg->sata1_reset = devm_reset_control_get_exclusive(dev, "sata1");
273 	if (IS_ERR(sg->sata1_reset)) {
274 		dev_err(dev, "no SATA1 reset controller\n");
275 		clk_disable_unprepare(sg->sata1_pclk);
276 		clk_disable_unprepare(sg->sata0_pclk);
277 		return PTR_ERR(sg->sata1_reset);
278 	}
279 
280 	sata_id = readl(sg->base + GEMINI_SATA_ID);
281 	sata_phy_id = readl(sg->base + GEMINI_SATA_PHY_ID);
282 	sg->sata_bridge = true;
283 	clk_disable(sg->sata0_pclk);
284 	clk_disable(sg->sata1_pclk);
285 
286 	dev_info(dev, "SATA ID %08x, PHY ID: %08x\n", sata_id, sata_phy_id);
287 
288 	return 0;
289 }
290 
291 static int gemini_setup_ide_pins(struct device *dev)
292 {
293 	struct pinctrl *p;
294 	struct pinctrl_state *ide_state;
295 	int ret;
296 
297 	p = devm_pinctrl_get(dev);
298 	if (IS_ERR(p))
299 		return PTR_ERR(p);
300 
301 	ide_state = pinctrl_lookup_state(p, "ide");
302 	if (IS_ERR(ide_state))
303 		return PTR_ERR(ide_state);
304 
305 	ret = pinctrl_select_state(p, ide_state);
306 	if (ret) {
307 		dev_err(dev, "could not select IDE state\n");
308 		return ret;
309 	}
310 
311 	return 0;
312 }
313 
314 static int gemini_sata_probe(struct platform_device *pdev)
315 {
316 	struct device *dev = &pdev->dev;
317 	struct device_node *np = dev->of_node;
318 	struct sata_gemini *sg;
319 	struct regmap *map;
320 	enum gemini_muxmode muxmode;
321 	u32 gmode;
322 	u32 gmask;
323 	int ret;
324 
325 	sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
326 	if (!sg)
327 		return -ENOMEM;
328 	sg->dev = dev;
329 
330 	sg->base = devm_platform_ioremap_resource(pdev, 0);
331 	if (IS_ERR(sg->base))
332 		return PTR_ERR(sg->base);
333 
334 	map = syscon_regmap_lookup_by_phandle(np, "syscon");
335 	if (IS_ERR(map)) {
336 		dev_err(dev, "no global syscon\n");
337 		return PTR_ERR(map);
338 	}
339 
340 	/* Set up the SATA bridge if need be */
341 	if (of_property_read_bool(np, "cortina,gemini-enable-sata-bridge")) {
342 		ret = gemini_sata_bridge_init(sg);
343 		if (ret)
344 			return ret;
345 	}
346 
347 	if (of_property_read_bool(np, "cortina,gemini-enable-ide-pins"))
348 		sg->ide_pins = true;
349 
350 	if (!sg->sata_bridge && !sg->ide_pins) {
351 		dev_err(dev, "neither SATA bridge or IDE output enabled\n");
352 		ret = -EINVAL;
353 		goto out_unprep_clk;
354 	}
355 
356 	ret = of_property_read_u32(np, "cortina,gemini-ata-muxmode", &muxmode);
357 	if (ret) {
358 		dev_err(dev, "could not parse ATA muxmode\n");
359 		goto out_unprep_clk;
360 	}
361 	if (muxmode > GEMINI_MUXMODE_3) {
362 		dev_err(dev, "illegal muxmode %d\n", muxmode);
363 		ret = -EINVAL;
364 		goto out_unprep_clk;
365 	}
366 	sg->muxmode = muxmode;
367 	gmask = GEMINI_IDE_IOMUX_MASK;
368 	gmode = (muxmode << GEMINI_IDE_IOMUX_SHIFT);
369 
370 	ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, gmask, gmode);
371 	if (ret) {
372 		dev_err(dev, "unable to set up IDE muxing\n");
373 		ret = -ENODEV;
374 		goto out_unprep_clk;
375 	}
376 
377 	/*
378 	 * Route out the IDE pins if desired.
379 	 * This is done by looking up a special pin control state called
380 	 * "ide" that will route out the IDE pins.
381 	 */
382 	if (sg->ide_pins) {
383 		ret = gemini_setup_ide_pins(dev);
384 		if (ret)
385 			return ret;
386 	}
387 
388 	dev_info(dev, "set up the Gemini IDE/SATA nexus\n");
389 	platform_set_drvdata(pdev, sg);
390 	sg_singleton = sg;
391 
392 	return 0;
393 
394 out_unprep_clk:
395 	if (sg->sata_bridge) {
396 		clk_unprepare(sg->sata1_pclk);
397 		clk_unprepare(sg->sata0_pclk);
398 	}
399 	return ret;
400 }
401 
402 static void gemini_sata_remove(struct platform_device *pdev)
403 {
404 	struct sata_gemini *sg = platform_get_drvdata(pdev);
405 
406 	if (sg->sata_bridge) {
407 		clk_unprepare(sg->sata1_pclk);
408 		clk_unprepare(sg->sata0_pclk);
409 	}
410 	sg_singleton = NULL;
411 }
412 
413 static const struct of_device_id gemini_sata_of_match[] = {
414 	{ .compatible = "cortina,gemini-sata-bridge", },
415 	{ /* sentinel */ }
416 };
417 
418 static struct platform_driver gemini_sata_driver = {
419 	.driver = {
420 		.name = DRV_NAME,
421 		.of_match_table = gemini_sata_of_match,
422 	},
423 	.probe = gemini_sata_probe,
424 	.remove_new = gemini_sata_remove,
425 };
426 module_platform_driver(gemini_sata_driver);
427 
428 MODULE_DESCRIPTION("low level driver for Cortina Systems Gemini SATA bridge");
429 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
430 MODULE_LICENSE("GPL");
431 MODULE_ALIAS("platform:" DRV_NAME);
432