1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  pci-rcar-gen2: internal PCI bus support
4  *
5  * Copyright (C) 2013 Renesas Solutions Corp.
6  * Copyright (C) 2013 Cogent Embedded, Inc.
7  *
8  * Author: Valentine Barshak <valentine.barshak@cogentembedded.com>
9  */
10 
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/of_address.h>
17 #include <linux/of_pci.h>
18 #include <linux/pci.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/sizes.h>
22 #include <linux/slab.h>
23 
24 #include "../pci.h"
25 
26 /* AHB-PCI Bridge PCI communication registers */
27 #define RCAR_AHBPCI_PCICOM_OFFSET	0x800
28 
29 #define RCAR_PCIAHB_WIN1_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x00)
30 #define RCAR_PCIAHB_WIN2_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x04)
31 #define RCAR_PCIAHB_PREFETCH0		0x0
32 #define RCAR_PCIAHB_PREFETCH4		0x1
33 #define RCAR_PCIAHB_PREFETCH8		0x2
34 #define RCAR_PCIAHB_PREFETCH16		0x3
35 
36 #define RCAR_AHBPCI_WIN1_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x10)
37 #define RCAR_AHBPCI_WIN2_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x14)
38 #define RCAR_AHBPCI_WIN_CTR_MEM		(3 << 1)
39 #define RCAR_AHBPCI_WIN_CTR_CFG		(5 << 1)
40 #define RCAR_AHBPCI_WIN1_HOST		(1 << 30)
41 #define RCAR_AHBPCI_WIN1_DEVICE		(1 << 31)
42 
43 #define RCAR_PCI_INT_ENABLE_REG		(RCAR_AHBPCI_PCICOM_OFFSET + 0x20)
44 #define RCAR_PCI_INT_STATUS_REG		(RCAR_AHBPCI_PCICOM_OFFSET + 0x24)
45 #define RCAR_PCI_INT_SIGTABORT		(1 << 0)
46 #define RCAR_PCI_INT_SIGRETABORT	(1 << 1)
47 #define RCAR_PCI_INT_REMABORT		(1 << 2)
48 #define RCAR_PCI_INT_PERR		(1 << 3)
49 #define RCAR_PCI_INT_SIGSERR		(1 << 4)
50 #define RCAR_PCI_INT_RESERR		(1 << 5)
51 #define RCAR_PCI_INT_WIN1ERR		(1 << 12)
52 #define RCAR_PCI_INT_WIN2ERR		(1 << 13)
53 #define RCAR_PCI_INT_A			(1 << 16)
54 #define RCAR_PCI_INT_B			(1 << 17)
55 #define RCAR_PCI_INT_PME		(1 << 19)
56 #define RCAR_PCI_INT_ALLERRORS (RCAR_PCI_INT_SIGTABORT		| \
57 				RCAR_PCI_INT_SIGRETABORT	| \
58 				RCAR_PCI_INT_REMABORT		| \
59 				RCAR_PCI_INT_PERR		| \
60 				RCAR_PCI_INT_SIGSERR		| \
61 				RCAR_PCI_INT_RESERR		| \
62 				RCAR_PCI_INT_WIN1ERR		| \
63 				RCAR_PCI_INT_WIN2ERR)
64 
65 #define RCAR_AHB_BUS_CTR_REG		(RCAR_AHBPCI_PCICOM_OFFSET + 0x30)
66 #define RCAR_AHB_BUS_MMODE_HTRANS	(1 << 0)
67 #define RCAR_AHB_BUS_MMODE_BYTE_BURST	(1 << 1)
68 #define RCAR_AHB_BUS_MMODE_WR_INCR	(1 << 2)
69 #define RCAR_AHB_BUS_MMODE_HBUS_REQ	(1 << 7)
70 #define RCAR_AHB_BUS_SMODE_READYCTR	(1 << 17)
71 #define RCAR_AHB_BUS_MODE		(RCAR_AHB_BUS_MMODE_HTRANS |	\
72 					RCAR_AHB_BUS_MMODE_BYTE_BURST |	\
73 					RCAR_AHB_BUS_MMODE_WR_INCR |	\
74 					RCAR_AHB_BUS_MMODE_HBUS_REQ |	\
75 					RCAR_AHB_BUS_SMODE_READYCTR)
76 
77 #define RCAR_USBCTR_REG			(RCAR_AHBPCI_PCICOM_OFFSET + 0x34)
78 #define RCAR_USBCTR_USBH_RST		(1 << 0)
79 #define RCAR_USBCTR_PCICLK_MASK		(1 << 1)
80 #define RCAR_USBCTR_PLL_RST		(1 << 2)
81 #define RCAR_USBCTR_DIRPD		(1 << 8)
82 #define RCAR_USBCTR_PCIAHB_WIN2_EN	(1 << 9)
83 #define RCAR_USBCTR_PCIAHB_WIN1_256M	(0 << 10)
84 #define RCAR_USBCTR_PCIAHB_WIN1_512M	(1 << 10)
85 #define RCAR_USBCTR_PCIAHB_WIN1_1G	(2 << 10)
86 #define RCAR_USBCTR_PCIAHB_WIN1_2G	(3 << 10)
87 #define RCAR_USBCTR_PCIAHB_WIN1_MASK	(3 << 10)
88 
89 #define RCAR_PCI_ARBITER_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x40)
90 #define RCAR_PCI_ARBITER_PCIREQ0	(1 << 0)
91 #define RCAR_PCI_ARBITER_PCIREQ1	(1 << 1)
92 #define RCAR_PCI_ARBITER_PCIBP_MODE	(1 << 12)
93 
94 #define RCAR_PCI_UNIT_REV_REG		(RCAR_AHBPCI_PCICOM_OFFSET + 0x48)
95 
96 struct rcar_pci {
97 	struct device *dev;
98 	void __iomem *reg;
99 	struct resource mem_res;
100 	struct resource *cfg_res;
101 	int irq;
102 };
103 
104 /* PCI configuration space operations */
105 static void __iomem *rcar_pci_cfg_base(struct pci_bus *bus, unsigned int devfn,
106 				       int where)
107 {
108 	struct rcar_pci *priv = bus->sysdata;
109 	int slot, val;
110 
111 	if (!pci_is_root_bus(bus) || PCI_FUNC(devfn))
112 		return NULL;
113 
114 	/* Only one EHCI/OHCI device built-in */
115 	slot = PCI_SLOT(devfn);
116 	if (slot > 2)
117 		return NULL;
118 
119 	/* bridge logic only has registers to 0x40 */
120 	if (slot == 0x0 && where >= 0x40)
121 		return NULL;
122 
123 	val = slot ? RCAR_AHBPCI_WIN1_DEVICE | RCAR_AHBPCI_WIN_CTR_CFG :
124 		     RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG;
125 
126 	iowrite32(val, priv->reg + RCAR_AHBPCI_WIN1_CTR_REG);
127 	return priv->reg + (slot >> 1) * 0x100 + where;
128 }
129 
130 #ifdef CONFIG_PCI_DEBUG
131 /* if debug enabled, then attach an error handler irq to the bridge */
132 
133 static irqreturn_t rcar_pci_err_irq(int irq, void *pw)
134 {
135 	struct rcar_pci *priv = pw;
136 	struct device *dev = priv->dev;
137 	u32 status = ioread32(priv->reg + RCAR_PCI_INT_STATUS_REG);
138 
139 	if (status & RCAR_PCI_INT_ALLERRORS) {
140 		dev_err(dev, "error irq: status %08x\n", status);
141 
142 		/* clear the error(s) */
143 		iowrite32(status & RCAR_PCI_INT_ALLERRORS,
144 			  priv->reg + RCAR_PCI_INT_STATUS_REG);
145 		return IRQ_HANDLED;
146 	}
147 
148 	return IRQ_NONE;
149 }
150 
151 static void rcar_pci_setup_errirq(struct rcar_pci *priv)
152 {
153 	struct device *dev = priv->dev;
154 	int ret;
155 	u32 val;
156 
157 	ret = devm_request_irq(dev, priv->irq, rcar_pci_err_irq,
158 			       IRQF_SHARED, "error irq", priv);
159 	if (ret) {
160 		dev_err(dev, "cannot claim IRQ for error handling\n");
161 		return;
162 	}
163 
164 	val = ioread32(priv->reg + RCAR_PCI_INT_ENABLE_REG);
165 	val |= RCAR_PCI_INT_ALLERRORS;
166 	iowrite32(val, priv->reg + RCAR_PCI_INT_ENABLE_REG);
167 }
168 #else
169 static inline void rcar_pci_setup_errirq(struct rcar_pci *priv) { }
170 #endif
171 
172 /* PCI host controller setup */
173 static void rcar_pci_setup(struct rcar_pci *priv)
174 {
175 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(priv);
176 	struct device *dev = priv->dev;
177 	void __iomem *reg = priv->reg;
178 	struct resource_entry *entry;
179 	unsigned long window_size;
180 	unsigned long window_addr;
181 	unsigned long window_pci;
182 	u32 val;
183 
184 	entry = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
185 	if (!entry) {
186 		window_addr = 0x40000000;
187 		window_pci = 0x40000000;
188 		window_size = SZ_1G;
189 	} else {
190 		window_addr = entry->res->start;
191 		window_pci = entry->res->start - entry->offset;
192 		window_size = resource_size(entry->res);
193 	}
194 
195 	pm_runtime_enable(dev);
196 	pm_runtime_get_sync(dev);
197 
198 	val = ioread32(reg + RCAR_PCI_UNIT_REV_REG);
199 	dev_info(dev, "PCI: revision %x\n", val);
200 
201 	/* Disable Direct Power Down State and assert reset */
202 	val = ioread32(reg + RCAR_USBCTR_REG) & ~RCAR_USBCTR_DIRPD;
203 	val |= RCAR_USBCTR_USBH_RST | RCAR_USBCTR_PLL_RST;
204 	iowrite32(val, reg + RCAR_USBCTR_REG);
205 	udelay(4);
206 
207 	/* De-assert reset and reset PCIAHB window1 size */
208 	val &= ~(RCAR_USBCTR_PCIAHB_WIN1_MASK | RCAR_USBCTR_PCICLK_MASK |
209 		 RCAR_USBCTR_USBH_RST | RCAR_USBCTR_PLL_RST);
210 
211 	/* Setup PCIAHB window1 size */
212 	switch (window_size) {
213 	case SZ_2G:
214 		val |= RCAR_USBCTR_PCIAHB_WIN1_2G;
215 		break;
216 	case SZ_1G:
217 		val |= RCAR_USBCTR_PCIAHB_WIN1_1G;
218 		break;
219 	case SZ_512M:
220 		val |= RCAR_USBCTR_PCIAHB_WIN1_512M;
221 		break;
222 	default:
223 		pr_warn("unknown window size %ld - defaulting to 256M\n",
224 			window_size);
225 		window_size = SZ_256M;
226 		fallthrough;
227 	case SZ_256M:
228 		val |= RCAR_USBCTR_PCIAHB_WIN1_256M;
229 		break;
230 	}
231 	iowrite32(val, reg + RCAR_USBCTR_REG);
232 
233 	/* Configure AHB master and slave modes */
234 	iowrite32(RCAR_AHB_BUS_MODE, reg + RCAR_AHB_BUS_CTR_REG);
235 
236 	/* Configure PCI arbiter */
237 	val = ioread32(reg + RCAR_PCI_ARBITER_CTR_REG);
238 	val |= RCAR_PCI_ARBITER_PCIREQ0 | RCAR_PCI_ARBITER_PCIREQ1 |
239 	       RCAR_PCI_ARBITER_PCIBP_MODE;
240 	iowrite32(val, reg + RCAR_PCI_ARBITER_CTR_REG);
241 
242 	/* PCI-AHB mapping */
243 	iowrite32(window_addr | RCAR_PCIAHB_PREFETCH16,
244 		  reg + RCAR_PCIAHB_WIN1_CTR_REG);
245 
246 	/* AHB-PCI mapping: OHCI/EHCI registers */
247 	val = priv->mem_res.start | RCAR_AHBPCI_WIN_CTR_MEM;
248 	iowrite32(val, reg + RCAR_AHBPCI_WIN2_CTR_REG);
249 
250 	/* Enable AHB-PCI bridge PCI configuration access */
251 	iowrite32(RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG,
252 		  reg + RCAR_AHBPCI_WIN1_CTR_REG);
253 	/* Set PCI-AHB Window1 address */
254 	iowrite32(window_pci | PCI_BASE_ADDRESS_MEM_PREFETCH,
255 		  reg + PCI_BASE_ADDRESS_1);
256 	/* Set AHB-PCI bridge PCI communication area address */
257 	val = priv->cfg_res->start + RCAR_AHBPCI_PCICOM_OFFSET;
258 	iowrite32(val, reg + PCI_BASE_ADDRESS_0);
259 
260 	val = ioread32(reg + PCI_COMMAND);
261 	val |= PCI_COMMAND_SERR | PCI_COMMAND_PARITY |
262 	       PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
263 	iowrite32(val, reg + PCI_COMMAND);
264 
265 	/* Enable PCI interrupts */
266 	iowrite32(RCAR_PCI_INT_A | RCAR_PCI_INT_B | RCAR_PCI_INT_PME,
267 		  reg + RCAR_PCI_INT_ENABLE_REG);
268 
269 	rcar_pci_setup_errirq(priv);
270 }
271 
272 static struct pci_ops rcar_pci_ops = {
273 	.map_bus = rcar_pci_cfg_base,
274 	.read	= pci_generic_config_read,
275 	.write	= pci_generic_config_write,
276 };
277 
278 static int rcar_pci_probe(struct platform_device *pdev)
279 {
280 	struct device *dev = &pdev->dev;
281 	struct resource *cfg_res, *mem_res;
282 	struct rcar_pci *priv;
283 	struct pci_host_bridge *bridge;
284 	void __iomem *reg;
285 
286 	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*priv));
287 	if (!bridge)
288 		return -ENOMEM;
289 
290 	priv = pci_host_bridge_priv(bridge);
291 	bridge->sysdata = priv;
292 
293 	cfg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
294 	reg = devm_ioremap_resource(dev, cfg_res);
295 	if (IS_ERR(reg))
296 		return PTR_ERR(reg);
297 
298 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
299 	if (!mem_res || !mem_res->start)
300 		return -ENODEV;
301 
302 	if (mem_res->start & 0xFFFF)
303 		return -EINVAL;
304 
305 	priv->mem_res = *mem_res;
306 	priv->cfg_res = cfg_res;
307 
308 	priv->irq = platform_get_irq(pdev, 0);
309 	priv->reg = reg;
310 	priv->dev = dev;
311 
312 	if (priv->irq < 0) {
313 		dev_err(dev, "no valid irq found\n");
314 		return priv->irq;
315 	}
316 
317 	bridge->ops = &rcar_pci_ops;
318 
319 	pci_add_flags(PCI_REASSIGN_ALL_BUS);
320 
321 	rcar_pci_setup(priv);
322 
323 	return pci_host_probe(bridge);
324 }
325 
326 static const struct of_device_id rcar_pci_of_match[] = {
327 	{ .compatible = "renesas,pci-r8a7790", },
328 	{ .compatible = "renesas,pci-r8a7791", },
329 	{ .compatible = "renesas,pci-r8a7794", },
330 	{ .compatible = "renesas,pci-rcar-gen2", },
331 	{ .compatible = "renesas,pci-rzn1", },
332 	{ },
333 };
334 
335 static struct platform_driver rcar_pci_driver = {
336 	.driver = {
337 		.name = "pci-rcar-gen2",
338 		.suppress_bind_attrs = true,
339 		.of_match_table = rcar_pci_of_match,
340 	},
341 	.probe = rcar_pci_probe,
342 };
343 builtin_platform_driver(rcar_pci_driver);
344