2 * PCIe driver for PLX NAS782X SoCs
4 * Author: Ma Haijun <mahaijuns@gmail.com>
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
11 #include <linux/kernel.h>
12 #include <linux/pci.h>
13 #include <linux/clk.h>
14 #include <linux/module.h>
15 #include <linux/mbus.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/slab.h>
18 #include <linux/platform_device.h>
19 #include <linux/of_address.h>
20 #include <linux/of_device.h>
21 #include <linux/of_gpio.h>
22 #include <linux/of_irq.h>
23 #include <linux/of_pci.h>
24 #include <linux/of_platform.h>
25 #include <linux/gpio.h>
26 #include <linux/delay.h>
27 #include <linux/clk.h>
28 #include <linux/regmap.h>
29 #include <linux/reset.h>
31 #include <linux/sizes.h>
33 #define SYS_CTRL_HCSL_CTRL_REGOFFSET 0x114
35 static inline void oxnas_register_clear_mask(void __iomem *p, unsigned mask)
37 u32 val = readl_relaxed(p);
40 writel_relaxed(val, p);
43 static inline void oxnas_register_set_mask(void __iomem *p, unsigned mask)
45 u32 val = readl_relaxed(p);
48 writel_relaxed(val, p);
51 static inline void oxnas_register_value_mask(void __iomem *p,
52 unsigned mask, unsigned new_value)
54 /* TODO sanity check mask & new_value = new_value */
55 u32 val = readl_relaxed(p);
59 writel_relaxed(val, p);
62 #define VERSION_ID_MAGIC 0x082510b5
63 #define LINK_UP_TIMEOUT_SECONDS 1
64 #define NUM_CONTROLLERS 1
67 PCIE_DEVICE_TYPE_MASK = 0x0F,
68 PCIE_DEVICE_TYPE_ENDPOINT = 0,
69 PCIE_DEVICE_TYPE_LEGACY_ENDPOINT = 1,
70 PCIE_DEVICE_TYPE_ROOT = 4,
73 PCIE_READY_ENTR_L23 = BIT(9),
74 PCIE_LINK_UP = BIT(11),
75 PCIE_OBTRANS = BIT(12),
79 HCSL_BIAS_ON = BIT(0),
80 HCSL_PCIE_EN = BIT(1),
81 HCSL_PCIEA_EN = BIT(2),
82 HCSL_PCIEB_EN = BIT(3),
86 /* pcie phy reg offset */
89 /* phy data reg bits */
95 /* core config registers */
97 PCI_CONFIG_VERSION_DEVICEID = 0,
98 PCI_CONFIG_COMMAND_STATUS = 4,
101 /* inbound config registers */
103 IB_ADDR_XLATE_ENABLE = 0xFC,
106 ENABLE_IN_ADDR_TRANS = BIT(0),
109 /* outbound config registers, offset relative to PCIE_POM0_MEM_ADDR */
111 PCIE_POM0_MEM_ADDR = 0,
112 PCIE_POM1_MEM_ADDR = 4,
113 PCIE_IN0_MEM_ADDR = 8,
114 PCIE_IN1_MEM_ADDR = 12,
115 PCIE_IN_IO_ADDR = 16,
116 PCIE_IN_CFG0_ADDR = 20,
117 PCIE_IN_CFG1_ADDR = 24,
118 PCIE_IN_MSG_ADDR = 28,
119 PCIE_IN0_MEM_LIMIT = 32,
120 PCIE_IN1_MEM_LIMIT = 36,
121 PCIE_IN_IO_LIMIT = 40,
122 PCIE_IN_CFG0_LIMIT = 44,
123 PCIE_IN_CFG1_LIMIT = 48,
124 PCIE_IN_MSG_LIMIT = 52,
125 PCIE_AHB_SLAVE_CTRL = 56,
127 PCIE_SLAVE_BE_SHIFT = 22,
130 #define ADDR_VAL(val) ((val) & 0xFFFF)
131 #define DATA_VAL(val) ((val) & 0xFFFF)
133 #define PCIE_SLAVE_BE(val) ((val) << PCIE_SLAVE_BE_SHIFT)
134 #define PCIE_SLAVE_BE_MASK PCIE_SLAVE_BE(0xF)
136 struct oxnas_pcie_shared {
137 /* seems all access are serialized, no lock required */
141 /* Structure representing one PCIe interfaces */
143 void __iomem *cfgbase;
145 void __iomem *inbound;
146 struct regmap *sys_ctrl;
147 unsigned int outbound_offset;
148 unsigned int pcie_ctrl_offset;
151 struct platform_device *pdev;
154 struct resource pre_mem; /* prefetchable */
155 struct resource non_mem; /* non-prefetchable */
156 struct resource busn; /* max available bus numbers */
157 int card_reset; /* gpio pin, optional */
158 unsigned hcsl_en; /* hcsl pci enable bit */
160 struct clk *busclk; /* for pcie bus, actually the PLLB */
161 void *private_data[1];
165 static struct oxnas_pcie_shared pcie_shared = {
169 static inline struct oxnas_pcie *sys_to_pcie(struct pci_sys_data *sys)
171 return sys->private_data;
175 static inline void set_out_lanes(struct oxnas_pcie *pcie, unsigned lanes)
177 regmap_update_bits(pcie->sys_ctrl, pcie->outbound_offset + PCIE_AHB_SLAVE_CTRL,
178 PCIE_SLAVE_BE_MASK, PCIE_SLAVE_BE(lanes));
182 static int oxnas_pcie_link_up(struct oxnas_pcie *pcie)
187 /* Poll for PCIE link up */
188 end = jiffies + (LINK_UP_TIMEOUT_SECONDS * HZ);
189 while (!time_after(jiffies, end)) {
190 regmap_read(pcie->sys_ctrl, pcie->pcie_ctrl_offset, &val);
191 if (val & PCIE_LINK_UP)
197 static void oxnas_pcie_setup_hw(struct oxnas_pcie *pcie)
199 /* We won't have any inbound address translation. This allows PCI
200 * devices to access anywhere in the AHB address map. Might be regarded
201 * as a bit dangerous, but let's get things working before we worry
204 oxnas_register_clear_mask(pcie->inbound + IB_ADDR_XLATE_ENABLE,
205 ENABLE_IN_ADDR_TRANS);
209 * Program outbound translation windows
211 * Outbound window is what is referred to as "PCI client" region in HRM
213 * Could use the larger alternative address space to get >>64M regions
214 * for graphics cards etc., but will not bother at this point.
216 * IP bug means that AMBA window size must be a power of 2
218 * Set mem0 window for first 16MB of outbound window non-prefetchable
219 * Set mem1 window for second 16MB of outbound window prefetchable
220 * Set io window for next 16MB of outbound window
221 * Set cfg0 for final 1MB of outbound window
223 * Ignore mem1, cfg1 and msg windows for now as no obvious use cases for
224 * 820 that would need them
226 * Probably ideally want no offset between mem0 window start as seen by
227 * ARM and as seen on PCI bus and get Linux to assign memory regions to
228 * PCI devices using the same "PCI client" region start address as seen
232 /* Set PCIeA mem0 region to be 1st 16MB of the 64MB PCIeA window */
233 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN0_MEM_ADDR, pcie->non_mem.start);
234 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN0_MEM_LIMIT, pcie->non_mem.end);
235 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_POM0_MEM_ADDR, pcie->non_mem.start);
237 /* Set PCIeA mem1 region to be 2nd 16MB of the 64MB PCIeA window */
238 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN1_MEM_ADDR, pcie->pre_mem.start);
239 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN1_MEM_LIMIT, pcie->pre_mem.end);
240 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_POM1_MEM_ADDR, pcie->pre_mem.start);
242 /* Set PCIeA io to be third 16M region of the 64MB PCIeA window*/
243 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_IO_ADDR, pcie->io.start);
244 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_IO_LIMIT, pcie->io.end);
247 /* Set PCIeA cgf0 to be last 16M region of the 64MB PCIeA window*/
248 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_CFG0_ADDR, pcie->cfg.start);
249 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_CFG0_LIMIT, pcie->cfg.end);
252 /* Enable outbound address translation */
253 regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset, PCIE_OBTRANS, PCIE_OBTRANS);
257 * Program PCIe command register for core to:
258 * enable memory space
262 writel_relaxed(7, pcie->base + PCI_CONFIG_COMMAND_STATUS);
267 static unsigned oxnas_pcie_cfg_to_offset(
268 struct pci_sys_data *sys,
269 unsigned char bus_number,
273 unsigned int function = PCI_FUNC(devfn);
274 unsigned int slot = PCI_SLOT(devfn);
275 unsigned char bus_number_offset;
277 bus_number_offset = bus_number - sys->busnr;
280 * We'll assume for now that the offset, function, slot, bus encoding
281 * should map onto linear, contiguous addresses in PCIe config space,
282 * albeit that the majority will be unused as only slot 0 is valid for
283 * any PCIe bus and most devices have only function 0
285 * Could be that PCIe in fact works by not encoding the slot number into
286 * the config space address as it's known that only slot 0 is valid.
287 * We'll have to experiment if/when we get a PCIe switch connected to
290 return (bus_number_offset << 20) | (slot << 15) | (function << 12) |
294 /* PCI configuration space write function */
295 static int oxnas_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
296 int where, int size, u32 val)
299 struct oxnas_pcie *pcie = sys_to_pcie(bus->sysdata);
304 /* Only a single device per bus for PCIe point-to-point links */
305 if (PCI_SLOT(devfn) > 0)
306 return PCIBIOS_DEVICE_NOT_FOUND;
309 return PCIBIOS_DEVICE_NOT_FOUND;
311 offset = oxnas_pcie_cfg_to_offset(bus->sysdata, bus->number, devfn,
314 value = val << (8 * (where & 3));
315 lanes = (0xf >> (4-size)) << (where & 3);
316 /* it race with mem and io write, but the possibility is low, normally
317 * all config writes happens at driver initialize stage, wont interleave
319 * and many pcie cards use dword (4bytes) access mem/io access only,
320 * so not bother to copy that ugly work-around now. */
321 spin_lock_irqsave(&pcie->lock, flags);
322 set_out_lanes(pcie, lanes);
323 writel_relaxed(value, pcie->cfgbase + offset);
324 set_out_lanes(pcie, 0xf);
325 spin_unlock_irqrestore(&pcie->lock, flags);
327 return PCIBIOS_SUCCESSFUL;
330 /* PCI configuration space read function */
331 static int oxnas_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
334 struct oxnas_pcie *pcie = sys_to_pcie(bus->sysdata);
337 u32 left_bytes, right_bytes;
339 /* Only a single device per bus for PCIe point-to-point links */
340 if (PCI_SLOT(devfn) > 0) {
342 return PCIBIOS_DEVICE_NOT_FOUND;
345 if (!pcie->haslink) {
347 return PCIBIOS_DEVICE_NOT_FOUND;
350 offset = oxnas_pcie_cfg_to_offset(bus->sysdata, bus->number, devfn,
352 value = readl_relaxed(pcie->cfgbase + offset);
353 left_bytes = where & 3;
354 right_bytes = 4 - left_bytes - size;
355 value <<= right_bytes * 8;
356 value >>= (left_bytes + right_bytes) * 8;
359 return PCIBIOS_SUCCESSFUL;
362 static struct pci_ops oxnas_pcie_ops = {
363 .read = oxnas_pcie_rd_conf,
364 .write = oxnas_pcie_wr_conf,
367 static int oxnas_pcie_setup(int nr, struct pci_sys_data *sys)
369 struct oxnas_pcie *pcie = sys_to_pcie(sys);
371 pci_add_resource_offset(&sys->resources, &pcie->non_mem, sys->mem_offset);
372 pci_add_resource_offset(&sys->resources, &pcie->pre_mem, sys->mem_offset);
373 pci_add_resource_offset(&sys->resources, &pcie->io, sys->io_offset);
374 pci_add_resource(&sys->resources, &pcie->busn);
375 if (sys->busnr == 0) { /* default one */
376 sys->busnr = pcie->busn.start;
378 /* do not use devm_ioremap_resource, it does not like cfg resource */
379 pcie->cfgbase = devm_ioremap(&pcie->pdev->dev, pcie->cfg.start,
380 resource_size(&pcie->cfg));
384 oxnas_pcie_setup_hw(pcie);
389 static void oxnas_pcie_enable(struct device *dev, struct oxnas_pcie *pcie)
394 memset(&hw, 0, sizeof(hw));
395 for (i = 0; i < NUM_CONTROLLERS; i++)
396 pcie->private_data[i] = pcie;
398 hw.nr_controllers = NUM_CONTROLLERS;
399 /* I think use stack pointer is a bad idea though it is valid in this case */
400 hw.private_data = pcie->private_data;
401 hw.setup = oxnas_pcie_setup;
402 hw.map_irq = of_irq_parse_and_map_pci;
403 hw.ops = &oxnas_pcie_ops;
405 /* pass dev to maintain of tree, interrupt mapping rely on this */
406 pci_common_init_dev(dev, &hw);
409 void oxnas_pcie_init_shared_hw(struct platform_device *pdev,
410 void __iomem *phybase,
411 struct regmap *sys_ctrl)
413 struct reset_control *rstc;
416 /* generate clocks from HCSL buffers, shared parts */
417 regmap_write(sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET, HCSL_BIAS_ON|HCSL_PCIE_EN);
419 /* Ensure PCIe PHY is properly reset */
420 rstc = reset_control_get(&pdev->dev, "phy");
424 ret = reset_control_reset(rstc);
425 reset_control_put(rstc);
429 dev_err(&pdev->dev, "phy reset failed %d\n", ret);
433 /* Enable PCIe Pre-Emphasis: What these value means? */
434 writel(ADDR_VAL(0x0014), phybase + PHY_ADDR);
435 writel(DATA_VAL(0xce10) | CAP_DATA, phybase + PHY_DATA);
436 writel(DATA_VAL(0xce10) | WRITE_EN, phybase + PHY_DATA);
438 writel(ADDR_VAL(0x2004), phybase + PHY_ADDR);
439 writel(DATA_VAL(0x82c7) | CAP_DATA, phybase + PHY_DATA);
440 writel(DATA_VAL(0x82c7) | WRITE_EN, phybase + PHY_DATA);
443 static int oxnas_pcie_shared_init(struct platform_device *pdev, struct regmap *sys_ctrl)
445 if (++pcie_shared.refcount == 1) {
446 /* we are the first */
447 struct device_node *np = pdev->dev.of_node;
448 void __iomem *phy = of_iomap(np, 2);
450 --pcie_shared.refcount;
453 oxnas_pcie_init_shared_hw(pdev, phy, sys_ctrl);
462 /* maybe we will call it when enter low power state */
463 static void oxnas_pcie_shared_deinit(struct platform_device *pdev)
465 if (--pcie_shared.refcount == 0) {
466 /* no cleanup needed */;
472 oxnas_pcie_map_registers(struct platform_device *pdev,
473 struct device_node *np,
474 struct oxnas_pcie *pcie)
476 struct resource regs;
478 u32 outbound_ctrl_offset;
479 u32 pcie_ctrl_offset;
481 /* 2 is reserved for shared phy */
482 ret = of_address_to_resource(np, 0, ®s);
485 pcie->base = devm_ioremap_resource(&pdev->dev, ®s);
489 ret = of_address_to_resource(np, 1, ®s);
492 pcie->inbound = devm_ioremap_resource(&pdev->dev, ®s);
497 if (of_property_read_u32(np, "plxtech,pcie-outbound-offset",
498 &outbound_ctrl_offset))
500 pcie->outbound_offset = outbound_ctrl_offset;
502 if (of_property_read_u32(np, "plxtech,pcie-ctrl-offset",
505 pcie->pcie_ctrl_offset = pcie_ctrl_offset;
510 static int oxnas_pcie_init_res(struct platform_device *pdev,
511 struct oxnas_pcie *pcie,
512 struct device_node *np)
514 struct of_pci_range range;
515 struct of_pci_range_parser parser;
518 if (of_pci_range_parser_init(&parser, np))
521 /* Get the I/O and memory ranges from DT */
522 for_each_of_pci_range(&parser, &range) {
524 unsigned long restype = range.flags & IORESOURCE_TYPE_BITS;
525 if (restype == IORESOURCE_IO) {
526 of_pci_range_to_resource(&range, np, &pcie->io);
527 pcie->io.name = "I/O";
529 if (restype == IORESOURCE_MEM) {
530 if (range.flags & IORESOURCE_PREFETCH) {
531 of_pci_range_to_resource(&range, np, &pcie->pre_mem);
532 pcie->pre_mem.name = "PRE MEM";
534 of_pci_range_to_resource(&range, np, &pcie->non_mem);
535 pcie->non_mem.name = "NON MEM";
540 of_pci_range_to_resource(&range, np, &pcie->cfg);
543 /* Get the bus range */
544 ret = of_pci_parse_bus_range(np, &pcie->busn);
547 dev_err(&pdev->dev, "failed to parse bus-range property: %d\n",
552 pcie->card_reset = of_get_gpio(np, 0);
553 if (pcie->card_reset < 0)
554 dev_info(&pdev->dev, "card reset gpio pin not exists\n");
556 if (of_property_read_u32(np, "plxtech,pcie-hcsl-bit", &pcie->hcsl_en))
559 pcie->clk = of_clk_get_by_name(np, "pcie");
560 if (IS_ERR(pcie->clk)) {
561 return PTR_ERR(pcie->clk);
564 pcie->busclk = of_clk_get_by_name(np, "busclk");
565 if (IS_ERR(pcie->busclk)) {
567 return PTR_ERR(pcie->busclk);
573 static void oxnas_pcie_init_hw(struct platform_device *pdev,
574 struct oxnas_pcie *pcie)
579 clk_prepare_enable(pcie->busclk);
581 /* reset PCIe cards use hard-wired gpio pin */
582 if (pcie->card_reset >= 0 &&
583 !gpio_direction_output(pcie->card_reset, 0)) {
586 /* must tri-state the pin to pull it up */
587 gpio_direction_input(pcie->card_reset);
592 regmap_update_bits(pcie->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET,
593 BIT(pcie->hcsl_en), BIT(pcie->hcsl_en));
596 ret = device_reset(&pdev->dev);
598 dev_err(&pdev->dev, "core reset failed %d\n", ret);
602 /* Start PCIe core clocks */
603 clk_prepare_enable(pcie->clk);
605 version_id = readl_relaxed(pcie->base + PCI_CONFIG_VERSION_DEVICEID);
606 dev_info(&pdev->dev, "PCIe version/deviceID 0x%x\n", version_id);
608 if (version_id != VERSION_ID_MAGIC) {
609 dev_info(&pdev->dev, "PCIe controller not found\n");
614 /* allow entry to L23 state */
615 regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
616 PCIE_READY_ENTR_L23, PCIE_READY_ENTR_L23);
618 /* Set PCIe core into RootCore mode */
619 regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
620 PCIE_DEVICE_TYPE_MASK, PCIE_DEVICE_TYPE_ROOT);
623 /* Bring up the PCI core */
624 regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
625 PCIE_LTSSM, PCIE_LTSSM);
629 static int oxnas_pcie_probe(struct platform_device *pdev)
631 struct oxnas_pcie *pcie;
632 struct device_node *np = pdev->dev.of_node;
635 pcie = devm_kzalloc(&pdev->dev, sizeof(struct oxnas_pcie),
642 spin_lock_init(&pcie->lock);
644 pcie->sys_ctrl = syscon_regmap_lookup_by_compatible("oxsemi,ox820-sys-ctrl");
645 if (IS_ERR(pcie->sys_ctrl))
646 return PTR_ERR(pcie->sys_ctrl);
648 ret = oxnas_pcie_init_res(pdev, pcie, np);
651 if (pcie->card_reset >= 0) {
652 ret = gpio_request_one(pcie->card_reset, GPIOF_DIR_IN,
653 dev_name(&pdev->dev));
655 dev_err(&pdev->dev, "cannot request gpio pin %d\n",
661 ret = oxnas_pcie_map_registers(pdev, np, pcie);
663 dev_err(&pdev->dev, "cannot map registers\n");
667 ret = oxnas_pcie_shared_init(pdev, pcie->sys_ctrl);
671 /* if hw not found, haslink cleared */
672 oxnas_pcie_init_hw(pdev, pcie);
674 if (pcie->haslink && oxnas_pcie_link_up(pcie)) {
676 dev_info(&pdev->dev, "link up\n");
679 dev_info(&pdev->dev, "link down\n");
681 /* should we register our controller even when pcie->haslink is 0 ? */
682 /* register the controller with framework */
683 oxnas_pcie_enable(&pdev->dev, pcie);
688 if (pcie->card_reset)
689 gpio_free(pcie->card_reset);
694 static const struct of_device_id oxnas_pcie_of_match_table[] = {
695 { .compatible = "plxtech,nas782x-pcie", },
699 static struct platform_driver oxnas_pcie_driver = {
701 .name = "oxnas-pcie",
702 .suppress_bind_attrs = true,
703 .of_match_table = oxnas_pcie_of_match_table,
705 .probe = oxnas_pcie_probe,
708 builtin_platform_driver(oxnas_pcie_driver);