1 // SPDX-License-Identifier: GPL-2.0+
2 /* Copyright (C) 2009 - 2019 Broadcom */
3 
4 #include <linux/bitfield.h>
5 #include <linux/bitops.h>
6 #include <linux/clk.h>
7 #include <linux/compiler.h>
8 #include <linux/delay.h>
9 #include <linux/init.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/ioport.h>
13 #include <linux/irqchip/chained_irq.h>
14 #include <linux/irqdomain.h>
15 #include <linux/kernel.h>
16 #include <linux/list.h>
17 #include <linux/log2.h>
18 #include <linux/module.h>
19 #include <linux/msi.h>
20 #include <linux/of_address.h>
21 #include <linux/of_irq.h>
22 #include <linux/of_pci.h>
23 #include <linux/of_platform.h>
24 #include <linux/pci.h>
25 #include <linux/printk.h>
26 #include <linux/sizes.h>
27 #include <linux/slab.h>
28 #include <linux/string.h>
29 #include <linux/types.h>
30 
31 #include "../pci.h"
32 
33 /* BRCM_PCIE_CAP_REGS - Offset for the mandatory capability config regs */
34 #define BRCM_PCIE_CAP_REGS				0x00ac
35 
36 /* Broadcom STB PCIe Register Offsets */
37 #define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1				0x0188
38 #define  PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK	0xc
39 #define  PCIE_RC_CFG_VENDOR_SPCIFIC_REG1_LITTLE_ENDIAN			0x0
40 
41 #define PCIE_RC_CFG_PRIV1_ID_VAL3			0x043c
42 #define  PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK	0xffffff
43 
44 #define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY			0x04dc
45 #define  PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK	0xc00
46 
47 #define PCIE_RC_DL_MDIO_ADDR				0x1100
48 #define PCIE_RC_DL_MDIO_WR_DATA				0x1104
49 #define PCIE_RC_DL_MDIO_RD_DATA				0x1108
50 
51 #define PCIE_MISC_MISC_CTRL				0x4008
52 #define  PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK		0x1000
53 #define  PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK	0x2000
54 #define  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK	0x300000
55 #define  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128		0x0
56 #define  PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK		0xf8000000
57 
58 #define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO		0x400c
59 #define PCIE_MEM_WIN0_LO(win)	\
60 		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO + ((win) * 8)
61 
62 #define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI		0x4010
63 #define PCIE_MEM_WIN0_HI(win)	\
64 		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI + ((win) * 8)
65 
66 #define PCIE_MISC_RC_BAR1_CONFIG_LO			0x402c
67 #define  PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK		0x1f
68 
69 #define PCIE_MISC_RC_BAR2_CONFIG_LO			0x4034
70 #define  PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK		0x1f
71 #define PCIE_MISC_RC_BAR2_CONFIG_HI			0x4038
72 
73 #define PCIE_MISC_RC_BAR3_CONFIG_LO			0x403c
74 #define  PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK		0x1f
75 
76 #define PCIE_MISC_MSI_BAR_CONFIG_LO			0x4044
77 #define PCIE_MISC_MSI_BAR_CONFIG_HI			0x4048
78 
79 #define PCIE_MISC_MSI_DATA_CONFIG			0x404c
80 #define  PCIE_MISC_MSI_DATA_CONFIG_VAL			0xffe06540
81 
82 #define PCIE_MISC_PCIE_CTRL				0x4064
83 #define  PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK	0x1
84 
85 #define PCIE_MISC_PCIE_STATUS				0x4068
86 #define  PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK		0x80
87 #define  PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK	0x20
88 #define  PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK	0x10
89 #define  PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK	0x40
90 
91 #define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT		0x4070
92 #define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK	0xfff00000
93 #define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK	0xfff0
94 #define PCIE_MEM_WIN0_BASE_LIMIT(win)	\
95 		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT + ((win) * 4)
96 
97 #define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI			0x4080
98 #define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK	0xff
99 #define PCIE_MEM_WIN0_BASE_HI(win)	\
100 		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI + ((win) * 8)
101 
102 #define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI			0x4084
103 #define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK	0xff
104 #define PCIE_MEM_WIN0_LIMIT_HI(win)	\
105 		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI + ((win) * 8)
106 
107 #define PCIE_MISC_HARD_PCIE_HARD_DEBUG					0x4204
108 #define  PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK	0x2
109 #define  PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK		0x08000000
110 
111 #define PCIE_MSI_INTR2_STATUS				0x4500
112 #define PCIE_MSI_INTR2_CLR				0x4508
113 #define PCIE_MSI_INTR2_MASK_SET				0x4510
114 #define PCIE_MSI_INTR2_MASK_CLR				0x4514
115 
116 #define PCIE_EXT_CFG_DATA				0x8000
117 
118 #define PCIE_EXT_CFG_INDEX				0x9000
119 #define  PCIE_EXT_BUSNUM_SHIFT				20
120 #define  PCIE_EXT_SLOT_SHIFT				15
121 #define  PCIE_EXT_FUNC_SHIFT				12
122 
123 #define PCIE_RGR1_SW_INIT_1				0x9210
124 #define  PCIE_RGR1_SW_INIT_1_PERST_MASK			0x1
125 #define  PCIE_RGR1_SW_INIT_1_INIT_MASK			0x2
126 
127 /* PCIe parameters */
128 #define BRCM_NUM_PCIE_OUT_WINS		0x4
129 #define BRCM_INT_PCI_MSI_NR		32
130 
131 /* MSI target adresses */
132 #define BRCM_MSI_TARGET_ADDR_LT_4GB	0x0fffffffcULL
133 #define BRCM_MSI_TARGET_ADDR_GT_4GB	0xffffffffcULL
134 
135 /* MDIO registers */
136 #define MDIO_PORT0			0x0
137 #define MDIO_DATA_MASK			0x7fffffff
138 #define MDIO_PORT_MASK			0xf0000
139 #define MDIO_REGAD_MASK			0xffff
140 #define MDIO_CMD_MASK			0xfff00000
141 #define MDIO_CMD_READ			0x1
142 #define MDIO_CMD_WRITE			0x0
143 #define MDIO_DATA_DONE_MASK		0x80000000
144 #define MDIO_RD_DONE(x)			(((x) & MDIO_DATA_DONE_MASK) ? 1 : 0)
145 #define MDIO_WT_DONE(x)			(((x) & MDIO_DATA_DONE_MASK) ? 0 : 1)
146 #define SSC_REGS_ADDR			0x1100
147 #define SET_ADDR_OFFSET			0x1f
148 #define SSC_CNTL_OFFSET			0x2
149 #define SSC_CNTL_OVRD_EN_MASK		0x8000
150 #define SSC_CNTL_OVRD_VAL_MASK		0x4000
151 #define SSC_STATUS_OFFSET		0x1
152 #define SSC_STATUS_SSC_MASK		0x400
153 #define SSC_STATUS_PLL_LOCK_MASK	0x800
154 
155 struct brcm_msi {
156 	struct device		*dev;
157 	void __iomem		*base;
158 	struct device_node	*np;
159 	struct irq_domain	*msi_domain;
160 	struct irq_domain	*inner_domain;
161 	struct mutex		lock; /* guards the alloc/free operations */
162 	u64			target_addr;
163 	int			irq;
164 	/* used indicates which MSI interrupts have been alloc'd */
165 	unsigned long		used;
166 };
167 
168 /* Internal PCIe Host Controller Information.*/
169 struct brcm_pcie {
170 	struct device		*dev;
171 	void __iomem		*base;
172 	struct clk		*clk;
173 	struct device_node	*np;
174 	bool			ssc;
175 	int			gen;
176 	u64			msi_target_addr;
177 	struct brcm_msi		*msi;
178 };
179 
180 /*
181  * This is to convert the size of the inbound "BAR" region to the
182  * non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE
183  */
184 static int brcm_pcie_encode_ibar_size(u64 size)
185 {
186 	int log2_in = ilog2(size);
187 
188 	if (log2_in >= 12 && log2_in <= 15)
189 		/* Covers 4KB to 32KB (inclusive) */
190 		return (log2_in - 12) + 0x1c;
191 	else if (log2_in >= 16 && log2_in <= 35)
192 		/* Covers 64KB to 32GB, (inclusive) */
193 		return log2_in - 15;
194 	/* Something is awry so disable */
195 	return 0;
196 }
197 
198 static u32 brcm_pcie_mdio_form_pkt(int port, int regad, int cmd)
199 {
200 	u32 pkt = 0;
201 
202 	pkt |= FIELD_PREP(MDIO_PORT_MASK, port);
203 	pkt |= FIELD_PREP(MDIO_REGAD_MASK, regad);
204 	pkt |= FIELD_PREP(MDIO_CMD_MASK, cmd);
205 
206 	return pkt;
207 }
208 
209 /* negative return value indicates error */
210 static int brcm_pcie_mdio_read(void __iomem *base, u8 port, u8 regad, u32 *val)
211 {
212 	int tries;
213 	u32 data;
214 
215 	writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_READ),
216 		   base + PCIE_RC_DL_MDIO_ADDR);
217 	readl(base + PCIE_RC_DL_MDIO_ADDR);
218 
219 	data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
220 	for (tries = 0; !MDIO_RD_DONE(data) && tries < 10; tries++) {
221 		udelay(10);
222 		data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
223 	}
224 
225 	*val = FIELD_GET(MDIO_DATA_MASK, data);
226 	return MDIO_RD_DONE(data) ? 0 : -EIO;
227 }
228 
229 /* negative return value indicates error */
230 static int brcm_pcie_mdio_write(void __iomem *base, u8 port,
231 				u8 regad, u16 wrdata)
232 {
233 	int tries;
234 	u32 data;
235 
236 	writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_WRITE),
237 		   base + PCIE_RC_DL_MDIO_ADDR);
238 	readl(base + PCIE_RC_DL_MDIO_ADDR);
239 	writel(MDIO_DATA_DONE_MASK | wrdata, base + PCIE_RC_DL_MDIO_WR_DATA);
240 
241 	data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
242 	for (tries = 0; !MDIO_WT_DONE(data) && tries < 10; tries++) {
243 		udelay(10);
244 		data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
245 	}
246 
247 	return MDIO_WT_DONE(data) ? 0 : -EIO;
248 }
249 
250 /*
251  * Configures device for Spread Spectrum Clocking (SSC) mode; a negative
252  * return value indicates error.
253  */
254 static int brcm_pcie_set_ssc(struct brcm_pcie *pcie)
255 {
256 	int pll, ssc;
257 	int ret;
258 	u32 tmp;
259 
260 	ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0, SET_ADDR_OFFSET,
261 				   SSC_REGS_ADDR);
262 	if (ret < 0)
263 		return ret;
264 
265 	ret = brcm_pcie_mdio_read(pcie->base, MDIO_PORT0,
266 				  SSC_CNTL_OFFSET, &tmp);
267 	if (ret < 0)
268 		return ret;
269 
270 	u32p_replace_bits(&tmp, 1, SSC_CNTL_OVRD_EN_MASK);
271 	u32p_replace_bits(&tmp, 1, SSC_CNTL_OVRD_VAL_MASK);
272 	ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0,
273 				   SSC_CNTL_OFFSET, tmp);
274 	if (ret < 0)
275 		return ret;
276 
277 	usleep_range(1000, 2000);
278 	ret = brcm_pcie_mdio_read(pcie->base, MDIO_PORT0,
279 				  SSC_STATUS_OFFSET, &tmp);
280 	if (ret < 0)
281 		return ret;
282 
283 	ssc = FIELD_GET(SSC_STATUS_SSC_MASK, tmp);
284 	pll = FIELD_GET(SSC_STATUS_PLL_LOCK_MASK, tmp);
285 
286 	return ssc && pll ? 0 : -EIO;
287 }
288 
289 /* Limits operation to a specific generation (1, 2, or 3) */
290 static void brcm_pcie_set_gen(struct brcm_pcie *pcie, int gen)
291 {
292 	u16 lnkctl2 = readw(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
293 	u32 lnkcap = readl(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
294 
295 	lnkcap = (lnkcap & ~PCI_EXP_LNKCAP_SLS) | gen;
296 	writel(lnkcap, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
297 
298 	lnkctl2 = (lnkctl2 & ~0xf) | gen;
299 	writew(lnkctl2, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
300 }
301 
302 static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
303 				       unsigned int win, u64 cpu_addr,
304 				       u64 pcie_addr, u64 size)
305 {
306 	u32 cpu_addr_mb_high, limit_addr_mb_high;
307 	phys_addr_t cpu_addr_mb, limit_addr_mb;
308 	int high_addr_shift;
309 	u32 tmp;
310 
311 	/* Set the base of the pcie_addr window */
312 	writel(lower_32_bits(pcie_addr), pcie->base + PCIE_MEM_WIN0_LO(win));
313 	writel(upper_32_bits(pcie_addr), pcie->base + PCIE_MEM_WIN0_HI(win));
314 
315 	/* Write the addr base & limit lower bits (in MBs) */
316 	cpu_addr_mb = cpu_addr / SZ_1M;
317 	limit_addr_mb = (cpu_addr + size - 1) / SZ_1M;
318 
319 	tmp = readl(pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));
320 	u32p_replace_bits(&tmp, cpu_addr_mb,
321 			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
322 	u32p_replace_bits(&tmp, limit_addr_mb,
323 			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK);
324 	writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));
325 
326 	/* Write the cpu & limit addr upper bits */
327 	high_addr_shift =
328 		HWEIGHT32(PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
329 
330 	cpu_addr_mb_high = cpu_addr_mb >> high_addr_shift;
331 	tmp = readl(pcie->base + PCIE_MEM_WIN0_BASE_HI(win));
332 	u32p_replace_bits(&tmp, cpu_addr_mb_high,
333 			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK);
334 	writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_HI(win));
335 
336 	limit_addr_mb_high = limit_addr_mb >> high_addr_shift;
337 	tmp = readl(pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
338 	u32p_replace_bits(&tmp, limit_addr_mb_high,
339 			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK);
340 	writel(tmp, pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
341 }
342 
343 static struct irq_chip brcm_msi_irq_chip = {
344 	.name            = "BRCM STB PCIe MSI",
345 	.irq_ack         = irq_chip_ack_parent,
346 	.irq_mask        = pci_msi_mask_irq,
347 	.irq_unmask      = pci_msi_unmask_irq,
348 };
349 
350 static struct msi_domain_info brcm_msi_domain_info = {
351 	/* Multi MSI is supported by the controller, but not by this driver */
352 	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
353 	.chip	= &brcm_msi_irq_chip,
354 };
355 
356 static void brcm_pcie_msi_isr(struct irq_desc *desc)
357 {
358 	struct irq_chip *chip = irq_desc_get_chip(desc);
359 	unsigned long status, virq;
360 	struct brcm_msi *msi;
361 	struct device *dev;
362 	u32 bit;
363 
364 	chained_irq_enter(chip, desc);
365 	msi = irq_desc_get_handler_data(desc);
366 	dev = msi->dev;
367 
368 	status = readl(msi->base + PCIE_MSI_INTR2_STATUS);
369 	for_each_set_bit(bit, &status, BRCM_INT_PCI_MSI_NR) {
370 		virq = irq_find_mapping(msi->inner_domain, bit);
371 		if (virq)
372 			generic_handle_irq(virq);
373 		else
374 			dev_dbg(dev, "unexpected MSI\n");
375 	}
376 
377 	chained_irq_exit(chip, desc);
378 }
379 
380 static void brcm_msi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
381 {
382 	struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
383 
384 	msg->address_lo = lower_32_bits(msi->target_addr);
385 	msg->address_hi = upper_32_bits(msi->target_addr);
386 	msg->data = (0xffff & PCIE_MISC_MSI_DATA_CONFIG_VAL) | data->hwirq;
387 }
388 
389 static int brcm_msi_set_affinity(struct irq_data *irq_data,
390 				 const struct cpumask *mask, bool force)
391 {
392 	return -EINVAL;
393 }
394 
395 static void brcm_msi_ack_irq(struct irq_data *data)
396 {
397 	struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
398 
399 	writel(1 << data->hwirq, msi->base + PCIE_MSI_INTR2_CLR);
400 }
401 
402 
403 static struct irq_chip brcm_msi_bottom_irq_chip = {
404 	.name			= "BRCM STB MSI",
405 	.irq_compose_msi_msg	= brcm_msi_compose_msi_msg,
406 	.irq_set_affinity	= brcm_msi_set_affinity,
407 	.irq_ack                = brcm_msi_ack_irq,
408 };
409 
410 static int brcm_msi_alloc(struct brcm_msi *msi)
411 {
412 	int hwirq;
413 
414 	mutex_lock(&msi->lock);
415 	hwirq = bitmap_find_free_region(&msi->used, BRCM_INT_PCI_MSI_NR, 0);
416 	mutex_unlock(&msi->lock);
417 
418 	return hwirq;
419 }
420 
421 static void brcm_msi_free(struct brcm_msi *msi, unsigned long hwirq)
422 {
423 	mutex_lock(&msi->lock);
424 	bitmap_release_region(&msi->used, hwirq, 0);
425 	mutex_unlock(&msi->lock);
426 }
427 
428 static int brcm_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
429 				 unsigned int nr_irqs, void *args)
430 {
431 	struct brcm_msi *msi = domain->host_data;
432 	int hwirq;
433 
434 	hwirq = brcm_msi_alloc(msi);
435 
436 	if (hwirq < 0)
437 		return hwirq;
438 
439 	irq_domain_set_info(domain, virq, (irq_hw_number_t)hwirq,
440 			    &brcm_msi_bottom_irq_chip, domain->host_data,
441 			    handle_edge_irq, NULL, NULL);
442 	return 0;
443 }
444 
445 static void brcm_irq_domain_free(struct irq_domain *domain,
446 				 unsigned int virq, unsigned int nr_irqs)
447 {
448 	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
449 	struct brcm_msi *msi = irq_data_get_irq_chip_data(d);
450 
451 	brcm_msi_free(msi, d->hwirq);
452 }
453 
454 static const struct irq_domain_ops msi_domain_ops = {
455 	.alloc	= brcm_irq_domain_alloc,
456 	.free	= brcm_irq_domain_free,
457 };
458 
459 static int brcm_allocate_domains(struct brcm_msi *msi)
460 {
461 	struct fwnode_handle *fwnode = of_node_to_fwnode(msi->np);
462 	struct device *dev = msi->dev;
463 
464 	msi->inner_domain = irq_domain_add_linear(NULL, BRCM_INT_PCI_MSI_NR,
465 						  &msi_domain_ops, msi);
466 	if (!msi->inner_domain) {
467 		dev_err(dev, "failed to create IRQ domain\n");
468 		return -ENOMEM;
469 	}
470 
471 	msi->msi_domain = pci_msi_create_irq_domain(fwnode,
472 						    &brcm_msi_domain_info,
473 						    msi->inner_domain);
474 	if (!msi->msi_domain) {
475 		dev_err(dev, "failed to create MSI domain\n");
476 		irq_domain_remove(msi->inner_domain);
477 		return -ENOMEM;
478 	}
479 
480 	return 0;
481 }
482 
483 static void brcm_free_domains(struct brcm_msi *msi)
484 {
485 	irq_domain_remove(msi->msi_domain);
486 	irq_domain_remove(msi->inner_domain);
487 }
488 
489 static void brcm_msi_remove(struct brcm_pcie *pcie)
490 {
491 	struct brcm_msi *msi = pcie->msi;
492 
493 	if (!msi)
494 		return;
495 	irq_set_chained_handler(msi->irq, NULL);
496 	irq_set_handler_data(msi->irq, NULL);
497 	brcm_free_domains(msi);
498 }
499 
500 static void brcm_msi_set_regs(struct brcm_msi *msi)
501 {
502 	writel(0xffffffff, msi->base + PCIE_MSI_INTR2_MASK_CLR);
503 
504 	/*
505 	 * The 0 bit of PCIE_MISC_MSI_BAR_CONFIG_LO is repurposed to MSI
506 	 * enable, which we set to 1.
507 	 */
508 	writel(lower_32_bits(msi->target_addr) | 0x1,
509 	       msi->base + PCIE_MISC_MSI_BAR_CONFIG_LO);
510 	writel(upper_32_bits(msi->target_addr),
511 	       msi->base + PCIE_MISC_MSI_BAR_CONFIG_HI);
512 
513 	writel(PCIE_MISC_MSI_DATA_CONFIG_VAL,
514 	       msi->base + PCIE_MISC_MSI_DATA_CONFIG);
515 }
516 
517 static int brcm_pcie_enable_msi(struct brcm_pcie *pcie)
518 {
519 	struct brcm_msi *msi;
520 	int irq, ret;
521 	struct device *dev = pcie->dev;
522 
523 	irq = irq_of_parse_and_map(dev->of_node, 1);
524 	if (irq <= 0) {
525 		dev_err(dev, "cannot map MSI interrupt\n");
526 		return -ENODEV;
527 	}
528 
529 	msi = devm_kzalloc(dev, sizeof(struct brcm_msi), GFP_KERNEL);
530 	if (!msi)
531 		return -ENOMEM;
532 
533 	mutex_init(&msi->lock);
534 	msi->dev = dev;
535 	msi->base = pcie->base;
536 	msi->np = pcie->np;
537 	msi->target_addr = pcie->msi_target_addr;
538 	msi->irq = irq;
539 
540 	ret = brcm_allocate_domains(msi);
541 	if (ret)
542 		return ret;
543 
544 	irq_set_chained_handler_and_data(msi->irq, brcm_pcie_msi_isr, msi);
545 
546 	brcm_msi_set_regs(msi);
547 	pcie->msi = msi;
548 
549 	return 0;
550 }
551 
552 /* The controller is capable of serving in both RC and EP roles */
553 static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
554 {
555 	void __iomem *base = pcie->base;
556 	u32 val = readl(base + PCIE_MISC_PCIE_STATUS);
557 
558 	return !!FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK, val);
559 }
560 
561 static bool brcm_pcie_link_up(struct brcm_pcie *pcie)
562 {
563 	u32 val = readl(pcie->base + PCIE_MISC_PCIE_STATUS);
564 	u32 dla = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK, val);
565 	u32 plu = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK, val);
566 
567 	return dla && plu;
568 }
569 
570 /* Configuration space read/write support */
571 static inline int brcm_pcie_cfg_index(int busnr, int devfn, int reg)
572 {
573 	return ((PCI_SLOT(devfn) & 0x1f) << PCIE_EXT_SLOT_SHIFT)
574 		| ((PCI_FUNC(devfn) & 0x07) << PCIE_EXT_FUNC_SHIFT)
575 		| (busnr << PCIE_EXT_BUSNUM_SHIFT)
576 		| (reg & ~3);
577 }
578 
579 static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
580 					int where)
581 {
582 	struct brcm_pcie *pcie = bus->sysdata;
583 	void __iomem *base = pcie->base;
584 	int idx;
585 
586 	/* Accesses to the RC go right to the RC registers if slot==0 */
587 	if (pci_is_root_bus(bus))
588 		return PCI_SLOT(devfn) ? NULL : base + where;
589 
590 	/* For devices, write to the config space index register */
591 	idx = brcm_pcie_cfg_index(bus->number, devfn, 0);
592 	writel(idx, pcie->base + PCIE_EXT_CFG_INDEX);
593 	return base + PCIE_EXT_CFG_DATA + where;
594 }
595 
596 static struct pci_ops brcm_pcie_ops = {
597 	.map_bus = brcm_pcie_map_conf,
598 	.read = pci_generic_config_read,
599 	.write = pci_generic_config_write,
600 };
601 
602 static inline void brcm_pcie_bridge_sw_init_set(struct brcm_pcie *pcie, u32 val)
603 {
604 	u32 tmp;
605 
606 	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1);
607 	u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_INIT_MASK);
608 	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1);
609 }
610 
611 static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie, u32 val)
612 {
613 	u32 tmp;
614 
615 	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1);
616 	u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
617 	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1);
618 }
619 
620 static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
621 							u64 *rc_bar2_size,
622 							u64 *rc_bar2_offset)
623 {
624 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
625 	struct device *dev = pcie->dev;
626 	struct resource_entry *entry;
627 
628 	entry = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
629 	if (!entry)
630 		return -ENODEV;
631 
632 
633 	/*
634 	 * The controller expects the inbound window offset to be calculated as
635 	 * the difference between PCIe's address space and CPU's. The offset
636 	 * provided by the firmware is calculated the opposite way, so we
637 	 * negate it.
638 	 */
639 	*rc_bar2_offset = -entry->offset;
640 	*rc_bar2_size = 1ULL << fls64(entry->res->end - entry->res->start);
641 
642 	/*
643 	 * We validate the inbound memory view even though we should trust
644 	 * whatever the device-tree provides. This is because of an HW issue on
645 	 * early Raspberry Pi 4's revisions (bcm2711). It turns out its
646 	 * firmware has to dynamically edit dma-ranges due to a bug on the
647 	 * PCIe controller integration, which prohibits any access above the
648 	 * lower 3GB of memory. Given this, we decided to keep the dma-ranges
649 	 * in check, avoiding hard to debug device-tree related issues in the
650 	 * future:
651 	 *
652 	 * The PCIe host controller by design must set the inbound viewport to
653 	 * be a contiguous arrangement of all of the system's memory.  In
654 	 * addition, its size mut be a power of two.  To further complicate
655 	 * matters, the viewport must start on a pcie-address that is aligned
656 	 * on a multiple of its size.  If a portion of the viewport does not
657 	 * represent system memory -- e.g. 3GB of memory requires a 4GB
658 	 * viewport -- we can map the outbound memory in or after 3GB and even
659 	 * though the viewport will overlap the outbound memory the controller
660 	 * will know to send outbound memory downstream and everything else
661 	 * upstream.
662 	 *
663 	 * For example:
664 	 *
665 	 * - The best-case scenario, memory up to 3GB, is to place the inbound
666 	 *   region in the first 4GB of pcie-space, as some legacy devices can
667 	 *   only address 32bits. We would also like to put the MSI under 4GB
668 	 *   as well, since some devices require a 32bit MSI target address.
669 	 *
670 	 * - If the system memory is 4GB or larger we cannot start the inbound
671 	 *   region at location 0 (since we have to allow some space for
672 	 *   outbound memory @ 3GB). So instead it will  start at the 1x
673 	 *   multiple of its size
674 	 */
675 	if (!*rc_bar2_size || (*rc_bar2_offset & (*rc_bar2_size - 1)) ||
676 	    (*rc_bar2_offset < SZ_4G && *rc_bar2_offset > SZ_2G)) {
677 		dev_err(dev, "Invalid rc_bar2_offset/size: size 0x%llx, off 0x%llx\n",
678 			*rc_bar2_size, *rc_bar2_offset);
679 		return -EINVAL;
680 	}
681 
682 	return 0;
683 }
684 
685 static int brcm_pcie_setup(struct brcm_pcie *pcie)
686 {
687 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
688 	u64 rc_bar2_offset, rc_bar2_size;
689 	void __iomem *base = pcie->base;
690 	struct device *dev = pcie->dev;
691 	struct resource_entry *entry;
692 	unsigned int scb_size_val;
693 	bool ssc_good = false;
694 	struct resource *res;
695 	int num_out_wins = 0;
696 	u16 nlw, cls, lnksta;
697 	int i, ret;
698 	u32 tmp, aspm_support;
699 
700 	/* Reset the bridge */
701 	brcm_pcie_bridge_sw_init_set(pcie, 1);
702 	brcm_pcie_perst_set(pcie, 1);
703 
704 	usleep_range(100, 200);
705 
706 	/* Take the bridge out of reset */
707 	brcm_pcie_bridge_sw_init_set(pcie, 0);
708 
709 	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
710 	tmp &= ~PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK;
711 	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
712 	/* Wait for SerDes to be stable */
713 	usleep_range(100, 200);
714 
715 	/* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN */
716 	u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK);
717 	u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK);
718 	u32p_replace_bits(&tmp, PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128,
719 			  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
720 	writel(tmp, base + PCIE_MISC_MISC_CTRL);
721 
722 	ret = brcm_pcie_get_rc_bar2_size_and_offset(pcie, &rc_bar2_size,
723 						    &rc_bar2_offset);
724 	if (ret)
725 		return ret;
726 
727 	tmp = lower_32_bits(rc_bar2_offset);
728 	u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(rc_bar2_size),
729 			  PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK);
730 	writel(tmp, base + PCIE_MISC_RC_BAR2_CONFIG_LO);
731 	writel(upper_32_bits(rc_bar2_offset),
732 	       base + PCIE_MISC_RC_BAR2_CONFIG_HI);
733 
734 	scb_size_val = rc_bar2_size ?
735 		       ilog2(rc_bar2_size) - 15 : 0xf; /* 0xf is 1GB */
736 	tmp = readl(base + PCIE_MISC_MISC_CTRL);
737 	u32p_replace_bits(&tmp, scb_size_val,
738 			  PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK);
739 	writel(tmp, base + PCIE_MISC_MISC_CTRL);
740 
741 	/*
742 	 * We ideally want the MSI target address to be located in the 32bit
743 	 * addressable memory area. Some devices might depend on it. This is
744 	 * possible either when the inbound window is located above the lower
745 	 * 4GB or when the inbound area is smaller than 4GB (taking into
746 	 * account the rounding-up we're forced to perform).
747 	 */
748 	if (rc_bar2_offset >= SZ_4G || (rc_bar2_size + rc_bar2_offset) < SZ_4G)
749 		pcie->msi_target_addr = BRCM_MSI_TARGET_ADDR_LT_4GB;
750 	else
751 		pcie->msi_target_addr = BRCM_MSI_TARGET_ADDR_GT_4GB;
752 
753 	/* disable the PCIe->GISB memory window (RC_BAR1) */
754 	tmp = readl(base + PCIE_MISC_RC_BAR1_CONFIG_LO);
755 	tmp &= ~PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK;
756 	writel(tmp, base + PCIE_MISC_RC_BAR1_CONFIG_LO);
757 
758 	/* disable the PCIe->SCB memory window (RC_BAR3) */
759 	tmp = readl(base + PCIE_MISC_RC_BAR3_CONFIG_LO);
760 	tmp &= ~PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK;
761 	writel(tmp, base + PCIE_MISC_RC_BAR3_CONFIG_LO);
762 
763 	/* Mask all interrupts since we are not handling any yet */
764 	writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_MASK_SET);
765 
766 	/* clear any interrupts we find on boot */
767 	writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_CLR);
768 
769 	if (pcie->gen)
770 		brcm_pcie_set_gen(pcie, pcie->gen);
771 
772 	/* Unassert the fundamental reset */
773 	brcm_pcie_perst_set(pcie, 0);
774 
775 	/*
776 	 * Give the RC/EP time to wake up, before trying to configure RC.
777 	 * Intermittently check status for link-up, up to a total of 100ms.
778 	 */
779 	for (i = 0; i < 100 && !brcm_pcie_link_up(pcie); i += 5)
780 		msleep(5);
781 
782 	if (!brcm_pcie_link_up(pcie)) {
783 		dev_err(dev, "link down\n");
784 		return -ENODEV;
785 	}
786 
787 	if (!brcm_pcie_rc_mode(pcie)) {
788 		dev_err(dev, "PCIe misconfigured; is in EP mode\n");
789 		return -EINVAL;
790 	}
791 
792 	resource_list_for_each_entry(entry, &bridge->windows) {
793 		res = entry->res;
794 
795 		if (resource_type(res) != IORESOURCE_MEM)
796 			continue;
797 
798 		if (num_out_wins >= BRCM_NUM_PCIE_OUT_WINS) {
799 			dev_err(pcie->dev, "too many outbound wins\n");
800 			return -EINVAL;
801 		}
802 
803 		brcm_pcie_set_outbound_win(pcie, num_out_wins, res->start,
804 					   res->start - entry->offset,
805 					   resource_size(res));
806 		num_out_wins++;
807 	}
808 
809 	/* Don't advertise L0s capability if 'aspm-no-l0s' */
810 	aspm_support = PCIE_LINK_STATE_L1;
811 	if (!of_property_read_bool(pcie->np, "aspm-no-l0s"))
812 		aspm_support |= PCIE_LINK_STATE_L0S;
813 	tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
814 	u32p_replace_bits(&tmp, aspm_support,
815 		PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK);
816 	writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
817 
818 	/*
819 	 * For config space accesses on the RC, show the right class for
820 	 * a PCIe-PCIe bridge (the default setting is to be EP mode).
821 	 */
822 	tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3);
823 	u32p_replace_bits(&tmp, 0x060400,
824 			  PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK);
825 	writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3);
826 
827 	if (pcie->ssc) {
828 		ret = brcm_pcie_set_ssc(pcie);
829 		if (ret == 0)
830 			ssc_good = true;
831 		else
832 			dev_err(dev, "failed attempt to enter ssc mode\n");
833 	}
834 
835 	lnksta = readw(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKSTA);
836 	cls = FIELD_GET(PCI_EXP_LNKSTA_CLS, lnksta);
837 	nlw = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta);
838 	dev_info(dev, "link up, %s x%u %s\n",
839 		 pci_speed_string(pcie_link_speed[cls]), nlw,
840 		 ssc_good ? "(SSC)" : "(!SSC)");
841 
842 	/* PCIe->SCB endian mode for BAR */
843 	tmp = readl(base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
844 	u32p_replace_bits(&tmp, PCIE_RC_CFG_VENDOR_SPCIFIC_REG1_LITTLE_ENDIAN,
845 		PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK);
846 	writel(tmp, base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
847 
848 	/*
849 	 * Refclk from RC should be gated with CLKREQ# input when ASPM L0s,L1
850 	 * is enabled => setting the CLKREQ_DEBUG_ENABLE field to 1.
851 	 */
852 	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
853 	tmp |= PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK;
854 	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
855 
856 	return 0;
857 }
858 
859 /* L23 is a low-power PCIe link state */
860 static void brcm_pcie_enter_l23(struct brcm_pcie *pcie)
861 {
862 	void __iomem *base = pcie->base;
863 	int l23, i;
864 	u32 tmp;
865 
866 	/* Assert request for L23 */
867 	tmp = readl(base + PCIE_MISC_PCIE_CTRL);
868 	u32p_replace_bits(&tmp, 1, PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK);
869 	writel(tmp, base + PCIE_MISC_PCIE_CTRL);
870 
871 	/* Wait up to 36 msec for L23 */
872 	tmp = readl(base + PCIE_MISC_PCIE_STATUS);
873 	l23 = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK, tmp);
874 	for (i = 0; i < 15 && !l23; i++) {
875 		usleep_range(2000, 2400);
876 		tmp = readl(base + PCIE_MISC_PCIE_STATUS);
877 		l23 = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK,
878 				tmp);
879 	}
880 
881 	if (!l23)
882 		dev_err(pcie->dev, "failed to enter low-power link state\n");
883 }
884 
885 static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
886 {
887 	void __iomem *base = pcie->base;
888 	int tmp;
889 
890 	if (brcm_pcie_link_up(pcie))
891 		brcm_pcie_enter_l23(pcie);
892 	/* Assert fundamental reset */
893 	brcm_pcie_perst_set(pcie, 1);
894 
895 	/* Deassert request for L23 in case it was asserted */
896 	tmp = readl(base + PCIE_MISC_PCIE_CTRL);
897 	u32p_replace_bits(&tmp, 0, PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK);
898 	writel(tmp, base + PCIE_MISC_PCIE_CTRL);
899 
900 	/* Turn off SerDes */
901 	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
902 	u32p_replace_bits(&tmp, 1, PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK);
903 	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
904 
905 	/* Shutdown PCIe bridge */
906 	brcm_pcie_bridge_sw_init_set(pcie, 1);
907 }
908 
909 static void __brcm_pcie_remove(struct brcm_pcie *pcie)
910 {
911 	brcm_msi_remove(pcie);
912 	brcm_pcie_turn_off(pcie);
913 	clk_disable_unprepare(pcie->clk);
914 }
915 
916 static int brcm_pcie_remove(struct platform_device *pdev)
917 {
918 	struct brcm_pcie *pcie = platform_get_drvdata(pdev);
919 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
920 
921 	pci_stop_root_bus(bridge->bus);
922 	pci_remove_root_bus(bridge->bus);
923 	__brcm_pcie_remove(pcie);
924 
925 	return 0;
926 }
927 
928 static int brcm_pcie_probe(struct platform_device *pdev)
929 {
930 	struct device_node *np = pdev->dev.of_node, *msi_np;
931 	struct pci_host_bridge *bridge;
932 	struct brcm_pcie *pcie;
933 	int ret;
934 
935 	bridge = devm_pci_alloc_host_bridge(&pdev->dev, sizeof(*pcie));
936 	if (!bridge)
937 		return -ENOMEM;
938 
939 	pcie = pci_host_bridge_priv(bridge);
940 	pcie->dev = &pdev->dev;
941 	pcie->np = np;
942 
943 	pcie->base = devm_platform_ioremap_resource(pdev, 0);
944 	if (IS_ERR(pcie->base))
945 		return PTR_ERR(pcie->base);
946 
947 	pcie->clk = devm_clk_get_optional(&pdev->dev, "sw_pcie");
948 	if (IS_ERR(pcie->clk))
949 		return PTR_ERR(pcie->clk);
950 
951 	ret = of_pci_get_max_link_speed(np);
952 	pcie->gen = (ret < 0) ? 0 : ret;
953 
954 	pcie->ssc = of_property_read_bool(np, "brcm,enable-ssc");
955 
956 	ret = clk_prepare_enable(pcie->clk);
957 	if (ret) {
958 		dev_err(&pdev->dev, "could not enable clock\n");
959 		return ret;
960 	}
961 
962 	ret = brcm_pcie_setup(pcie);
963 	if (ret)
964 		goto fail;
965 
966 	msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
967 	if (pci_msi_enabled() && msi_np == pcie->np) {
968 		ret = brcm_pcie_enable_msi(pcie);
969 		if (ret) {
970 			dev_err(pcie->dev, "probe of internal MSI failed");
971 			goto fail;
972 		}
973 	}
974 
975 	bridge->ops = &brcm_pcie_ops;
976 	bridge->sysdata = pcie;
977 
978 	platform_set_drvdata(pdev, pcie);
979 
980 	return pci_host_probe(bridge);
981 fail:
982 	__brcm_pcie_remove(pcie);
983 	return ret;
984 }
985 
986 static const struct of_device_id brcm_pcie_match[] = {
987 	{ .compatible = "brcm,bcm2711-pcie" },
988 	{},
989 };
990 MODULE_DEVICE_TABLE(of, brcm_pcie_match);
991 
992 static struct platform_driver brcm_pcie_driver = {
993 	.probe = brcm_pcie_probe,
994 	.remove = brcm_pcie_remove,
995 	.driver = {
996 		.name = "brcm-pcie",
997 		.of_match_table = brcm_pcie_match,
998 	},
999 };
1000 module_platform_driver(brcm_pcie_driver);
1001 
1002 MODULE_LICENSE("GPL");
1003 MODULE_DESCRIPTION("Broadcom STB PCIe RC driver");
1004 MODULE_AUTHOR("Broadcom");
1005