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/phy.h>
29 #include <linux/phy/phy.h>
30 #include <linux/regmap.h>
31 #include <linux/reset.h>
33 #include <linux/sizes.h>
37 #define SYS_CTRL_HCSL_CTRL_REGOFFSET 0x114
39 static inline void oxnas_register_clear_mask(void __iomem *p, unsigned mask)
41 u32 val = readl_relaxed(p);
44 writel_relaxed(val, p);
47 static inline void oxnas_register_set_mask(void __iomem *p, unsigned mask)
49 u32 val = readl_relaxed(p);
52 writel_relaxed(val, p);
55 static inline void oxnas_register_value_mask(void __iomem *p,
56 unsigned mask, unsigned new_value)
58 /* TODO sanity check mask & new_value = new_value */
59 u32 val = readl_relaxed(p);
63 writel_relaxed(val, p);
66 #define VERSION_ID_MAGIC 0x082510b5
67 #define LINK_UP_TIMEOUT_SECONDS 1
68 #define NUM_CONTROLLERS 1
71 PCIE_DEVICE_TYPE_MASK = 0x0F,
72 PCIE_DEVICE_TYPE_ENDPOINT = 0,
73 PCIE_DEVICE_TYPE_LEGACY_ENDPOINT = 1,
74 PCIE_DEVICE_TYPE_ROOT = 4,
77 PCIE_READY_ENTR_L23 = BIT(9),
78 PCIE_LINK_UP = BIT(11),
79 PCIE_OBTRANS = BIT(12),
82 /* core config registers */
84 PCI_CONFIG_VERSION_DEVICEID = 0,
85 PCI_CONFIG_COMMAND_STATUS = 4,
88 /* inbound config registers */
90 IB_ADDR_XLATE_ENABLE = 0xFC,
93 ENABLE_IN_ADDR_TRANS = BIT(0),
96 /* outbound config registers, offset relative to PCIE_POM0_MEM_ADDR */
98 PCIE_POM0_MEM_ADDR = 0,
99 PCIE_POM1_MEM_ADDR = 4,
100 PCIE_IN0_MEM_ADDR = 8,
101 PCIE_IN1_MEM_ADDR = 12,
102 PCIE_IN_IO_ADDR = 16,
103 PCIE_IN_CFG0_ADDR = 20,
104 PCIE_IN_CFG1_ADDR = 24,
105 PCIE_IN_MSG_ADDR = 28,
106 PCIE_IN0_MEM_LIMIT = 32,
107 PCIE_IN1_MEM_LIMIT = 36,
108 PCIE_IN_IO_LIMIT = 40,
109 PCIE_IN_CFG0_LIMIT = 44,
110 PCIE_IN_CFG1_LIMIT = 48,
111 PCIE_IN_MSG_LIMIT = 52,
112 PCIE_AHB_SLAVE_CTRL = 56,
114 PCIE_SLAVE_BE_SHIFT = 22,
117 #define PCIE_SLAVE_BE(val) ((val) << PCIE_SLAVE_BE_SHIFT)
118 #define PCIE_SLAVE_BE_MASK PCIE_SLAVE_BE(0xF)
120 struct oxnas_pcie_shared {
121 /* seems all access are serialized, no lock required */
125 /* Structure representing one PCIe interfaces */
127 void __iomem *cfgbase;
129 void __iomem *inbound;
130 struct regmap *sys_ctrl;
131 unsigned int outbound_offset;
132 unsigned int pcie_ctrl_offset;
135 struct platform_device *pdev;
138 struct resource pre_mem; /* prefetchable */
139 struct resource non_mem; /* non-prefetchable */
140 struct resource busn; /* max available bus numbers */
141 int card_reset; /* gpio pin, optional */
142 unsigned hcsl_en; /* hcsl pci enable bit */
144 struct clk *busclk; /* for pcie bus, actually the PLLB */
145 void *private_data[1];
149 static struct oxnas_pcie_shared pcie_shared = {
153 static inline struct oxnas_pcie *sys_to_pcie(struct pci_sys_data *sys)
155 return sys->private_data;
159 static inline void set_out_lanes(struct oxnas_pcie *pcie, unsigned lanes)
161 regmap_update_bits(pcie->sys_ctrl, pcie->outbound_offset + PCIE_AHB_SLAVE_CTRL,
162 PCIE_SLAVE_BE_MASK, PCIE_SLAVE_BE(lanes));
166 static int oxnas_pcie_link_up(struct oxnas_pcie *pcie)
171 /* Poll for PCIE link up */
172 end = jiffies + (LINK_UP_TIMEOUT_SECONDS * HZ);
173 while (!time_after(jiffies, end)) {
174 regmap_read(pcie->sys_ctrl, pcie->pcie_ctrl_offset, &val);
175 if (val & PCIE_LINK_UP)
181 static void oxnas_pcie_setup_hw(struct oxnas_pcie *pcie)
183 /* We won't have any inbound address translation. This allows PCI
184 * devices to access anywhere in the AHB address map. Might be regarded
185 * as a bit dangerous, but let's get things working before we worry
188 oxnas_register_clear_mask(pcie->inbound + IB_ADDR_XLATE_ENABLE,
189 ENABLE_IN_ADDR_TRANS);
193 * Program outbound translation windows
195 * Outbound window is what is referred to as "PCI client" region in HRM
197 * Could use the larger alternative address space to get >>64M regions
198 * for graphics cards etc., but will not bother at this point.
200 * IP bug means that AMBA window size must be a power of 2
202 * Set mem0 window for first 16MB of outbound window non-prefetchable
203 * Set mem1 window for second 16MB of outbound window prefetchable
204 * Set io window for next 16MB of outbound window
205 * Set cfg0 for final 1MB of outbound window
207 * Ignore mem1, cfg1 and msg windows for now as no obvious use cases for
208 * 820 that would need them
210 * Probably ideally want no offset between mem0 window start as seen by
211 * ARM and as seen on PCI bus and get Linux to assign memory regions to
212 * PCI devices using the same "PCI client" region start address as seen
216 /* Set PCIeA mem0 region to be 1st 16MB of the 64MB PCIeA window */
217 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN0_MEM_ADDR, pcie->non_mem.start);
218 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN0_MEM_LIMIT, pcie->non_mem.end);
219 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_POM0_MEM_ADDR, pcie->non_mem.start);
221 /* Set PCIeA mem1 region to be 2nd 16MB of the 64MB PCIeA window */
222 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN1_MEM_ADDR, pcie->pre_mem.start);
223 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN1_MEM_LIMIT, pcie->pre_mem.end);
224 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_POM1_MEM_ADDR, pcie->pre_mem.start);
226 /* Set PCIeA io to be third 16M region of the 64MB PCIeA window*/
227 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_IO_ADDR, pcie->io.start);
228 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_IO_LIMIT, pcie->io.end);
231 /* Set PCIeA cgf0 to be last 16M region of the 64MB PCIeA window*/
232 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_CFG0_ADDR, pcie->cfg.start);
233 regmap_write(pcie->sys_ctrl, pcie->outbound_offset + PCIE_IN_CFG0_LIMIT, pcie->cfg.end);
236 /* Enable outbound address translation */
237 regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset, PCIE_OBTRANS, PCIE_OBTRANS);
241 * Program PCIe command register for core to:
242 * enable memory space
246 writel_relaxed(7, pcie->base + PCI_CONFIG_COMMAND_STATUS);
251 static unsigned oxnas_pcie_cfg_to_offset(
252 struct pci_sys_data *sys,
253 unsigned char bus_number,
257 unsigned int function = PCI_FUNC(devfn);
258 unsigned int slot = PCI_SLOT(devfn);
259 unsigned char bus_number_offset;
261 bus_number_offset = bus_number - sys->busnr;
264 * We'll assume for now that the offset, function, slot, bus encoding
265 * should map onto linear, contiguous addresses in PCIe config space,
266 * albeit that the majority will be unused as only slot 0 is valid for
267 * any PCIe bus and most devices have only function 0
269 * Could be that PCIe in fact works by not encoding the slot number into
270 * the config space address as it's known that only slot 0 is valid.
271 * We'll have to experiment if/when we get a PCIe switch connected to
274 return (bus_number_offset << 20) | (slot << 15) | (function << 12) |
278 /* PCI configuration space write function */
279 static int oxnas_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
280 int where, int size, u32 val)
283 struct oxnas_pcie *pcie = sys_to_pcie(bus->sysdata);
288 /* Only a single device per bus for PCIe point-to-point links */
289 if (PCI_SLOT(devfn) > 0)
290 return PCIBIOS_DEVICE_NOT_FOUND;
293 return PCIBIOS_DEVICE_NOT_FOUND;
295 offset = oxnas_pcie_cfg_to_offset(bus->sysdata, bus->number, devfn,
298 value = val << (8 * (where & 3));
299 lanes = (0xf >> (4-size)) << (where & 3);
300 /* it race with mem and io write, but the possibility is low, normally
301 * all config writes happens at driver initialize stage, wont interleave
303 * and many pcie cards use dword (4bytes) access mem/io access only,
304 * so not bother to copy that ugly work-around now. */
305 spin_lock_irqsave(&pcie->lock, flags);
306 set_out_lanes(pcie, lanes);
307 writel_relaxed(value, pcie->cfgbase + offset);
308 set_out_lanes(pcie, 0xf);
309 spin_unlock_irqrestore(&pcie->lock, flags);
311 return PCIBIOS_SUCCESSFUL;
314 /* PCI configuration space read function */
315 static int oxnas_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
318 struct oxnas_pcie *pcie = sys_to_pcie(bus->sysdata);
321 u32 left_bytes, right_bytes;
323 /* Only a single device per bus for PCIe point-to-point links */
324 if (PCI_SLOT(devfn) > 0) {
326 return PCIBIOS_DEVICE_NOT_FOUND;
329 if (!pcie->haslink) {
331 return PCIBIOS_DEVICE_NOT_FOUND;
334 offset = oxnas_pcie_cfg_to_offset(bus->sysdata, bus->number, devfn,
336 value = readl_relaxed(pcie->cfgbase + offset);
337 left_bytes = where & 3;
338 right_bytes = 4 - left_bytes - size;
339 value <<= right_bytes * 8;
340 value >>= (left_bytes + right_bytes) * 8;
343 return PCIBIOS_SUCCESSFUL;
346 static struct pci_ops oxnas_pcie_ops = {
347 .read = oxnas_pcie_rd_conf,
348 .write = oxnas_pcie_wr_conf,
351 static int oxnas_pcie_setup(int nr, struct pci_sys_data *sys)
353 struct oxnas_pcie *pcie = sys_to_pcie(sys);
355 pci_add_resource_offset(&sys->resources, &pcie->non_mem, sys->mem_offset);
356 pci_add_resource_offset(&sys->resources, &pcie->pre_mem, sys->mem_offset);
357 pci_add_resource_offset(&sys->resources, &pcie->io, sys->io_offset);
358 pci_add_resource(&sys->resources, &pcie->busn);
359 if (sys->busnr == 0) { /* default one */
360 sys->busnr = pcie->busn.start;
362 /* do not use devm_ioremap_resource, it does not like cfg resource */
363 pcie->cfgbase = devm_ioremap(&pcie->pdev->dev, pcie->cfg.start,
364 resource_size(&pcie->cfg));
368 oxnas_pcie_setup_hw(pcie);
373 static void oxnas_pcie_enable(struct device *dev, struct oxnas_pcie *pcie)
378 memset(&hw, 0, sizeof(hw));
379 for (i = 0; i < NUM_CONTROLLERS; i++)
380 pcie->private_data[i] = pcie;
382 hw.nr_controllers = NUM_CONTROLLERS;
383 /* I think use stack pointer is a bad idea though it is valid in this case */
384 hw.private_data = pcie->private_data;
385 hw.setup = oxnas_pcie_setup;
386 hw.map_irq = of_irq_parse_and_map_pci;
387 hw.ops = &oxnas_pcie_ops;
389 /* pass dev to maintain of tree, interrupt mapping rely on this */
390 pci_common_init_dev(dev, &hw);
393 static int oxnas_pcie_shared_init(struct platform_device *pdev, struct oxnas_pcie *pcie)
395 if (++pcie_shared.refcount == 1) {
397 phy_power_on(pcie->phy);
405 /* maybe we will call it when enter low power state */
406 static void oxnas_pcie_shared_deinit(struct platform_device *pdev)
408 if (--pcie_shared.refcount == 0) {
409 /* no cleanup needed */;
415 oxnas_pcie_map_registers(struct platform_device *pdev,
416 struct device_node *np,
417 struct oxnas_pcie *pcie)
419 struct resource regs;
421 u32 outbound_ctrl_offset;
422 u32 pcie_ctrl_offset;
424 ret = of_address_to_resource(np, 0, ®s);
426 dev_err(&pdev->dev, "failed to parse base register space\n");
430 pcie->base = devm_ioremap_resource(&pdev->dev, ®s);
432 dev_err(&pdev->dev, "failed to map base register space\n");
436 ret = of_address_to_resource(np, 1, ®s);
438 dev_err(&pdev->dev, "failed to parse inbound register space\n");
442 pcie->inbound = devm_ioremap_resource(&pdev->dev, ®s);
443 if (!pcie->inbound) {
444 dev_err(&pdev->dev, "failed to map inbound register space\n");
448 pcie->phy = devm_of_phy_get(&pdev->dev, np, NULL);
449 if (IS_ERR(pcie->phy)) {
450 if (PTR_ERR(pcie->phy) == -EPROBE_DEFER) {
451 dev_err(&pdev->dev, "failed to probe phy\n");
452 return PTR_ERR(pcie->phy);
454 dev_warn(&pdev->dev, "phy not attached\n");
458 if (of_property_read_u32(np, "plxtech,pcie-outbound-offset",
459 &outbound_ctrl_offset)) {
460 dev_err(&pdev->dev, "failed to parse outbound register offset\n");
463 pcie->outbound_offset = outbound_ctrl_offset;
465 if (of_property_read_u32(np, "plxtech,pcie-ctrl-offset",
466 &pcie_ctrl_offset)) {
467 dev_err(&pdev->dev, "failed to parse pcie-ctrl register offset\n");
470 pcie->pcie_ctrl_offset = pcie_ctrl_offset;
475 static int oxnas_pcie_init_res(struct platform_device *pdev,
476 struct oxnas_pcie *pcie,
477 struct device_node *np)
479 struct of_pci_range range;
480 struct of_pci_range_parser parser;
483 if (of_pci_range_parser_init(&parser, np))
486 /* Get the I/O and memory ranges from DT */
487 for_each_of_pci_range(&parser, &range) {
489 unsigned long restype = range.flags & IORESOURCE_TYPE_BITS;
490 if (restype == IORESOURCE_IO) {
491 of_pci_range_to_resource(&range, np, &pcie->io);
492 pcie->io.name = "I/O";
494 if (restype == IORESOURCE_MEM) {
495 if (range.flags & IORESOURCE_PREFETCH) {
496 of_pci_range_to_resource(&range, np, &pcie->pre_mem);
497 pcie->pre_mem.name = "PRE MEM";
499 of_pci_range_to_resource(&range, np, &pcie->non_mem);
500 pcie->non_mem.name = "NON MEM";
505 of_pci_range_to_resource(&range, np, &pcie->cfg);
508 /* Get the bus range */
509 ret = of_pci_parse_bus_range(np, &pcie->busn);
512 dev_err(&pdev->dev, "failed to parse bus-range property: %d\n",
517 pcie->card_reset = of_get_gpio(np, 0);
518 if (pcie->card_reset < 0)
519 dev_info(&pdev->dev, "card reset gpio pin not exists\n");
521 if (of_property_read_u32(np, "plxtech,pcie-hcsl-bit", &pcie->hcsl_en))
524 pcie->clk = of_clk_get_by_name(np, "pcie");
525 if (IS_ERR(pcie->clk)) {
526 return PTR_ERR(pcie->clk);
529 pcie->busclk = of_clk_get_by_name(np, "busclk");
530 if (IS_ERR(pcie->busclk)) {
532 return PTR_ERR(pcie->busclk);
538 static void oxnas_pcie_init_hw(struct platform_device *pdev,
539 struct oxnas_pcie *pcie)
544 clk_prepare_enable(pcie->busclk);
546 /* reset PCIe cards use hard-wired gpio pin */
547 if (pcie->card_reset >= 0 &&
548 !gpio_direction_output(pcie->card_reset, 0)) {
551 /* must tri-state the pin to pull it up */
552 gpio_direction_input(pcie->card_reset);
557 /* ToDo: use phy power-on port... */
558 regmap_update_bits(pcie->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET,
559 BIT(pcie->hcsl_en), BIT(pcie->hcsl_en));
562 ret = device_reset(&pdev->dev);
564 dev_err(&pdev->dev, "core reset failed %d\n", ret);
568 /* Start PCIe core clocks */
569 clk_prepare_enable(pcie->clk);
571 version_id = readl_relaxed(pcie->base + PCI_CONFIG_VERSION_DEVICEID);
572 dev_info(&pdev->dev, "PCIe version/deviceID 0x%x\n", version_id);
574 if (version_id != VERSION_ID_MAGIC) {
575 dev_info(&pdev->dev, "PCIe controller not found\n");
580 /* allow entry to L23 state */
581 regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
582 PCIE_READY_ENTR_L23, PCIE_READY_ENTR_L23);
584 /* Set PCIe core into RootCore mode */
585 regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
586 PCIE_DEVICE_TYPE_MASK, PCIE_DEVICE_TYPE_ROOT);
589 /* Bring up the PCI core */
590 regmap_write_bits(pcie->sys_ctrl, pcie->pcie_ctrl_offset,
591 PCIE_LTSSM, PCIE_LTSSM);
595 static int oxnas_pcie_probe(struct platform_device *pdev)
597 struct oxnas_pcie *pcie;
598 struct device_node *np = pdev->dev.of_node;
601 pcie = devm_kzalloc(&pdev->dev, sizeof(struct oxnas_pcie),
608 spin_lock_init(&pcie->lock);
610 pcie->sys_ctrl = syscon_regmap_lookup_by_compatible("oxsemi,ox820-sys-ctrl");
611 if (IS_ERR(pcie->sys_ctrl))
612 return PTR_ERR(pcie->sys_ctrl);
614 ret = oxnas_pcie_init_res(pdev, pcie, np);
617 if (pcie->card_reset >= 0) {
618 ret = gpio_request_one(pcie->card_reset, GPIOF_DIR_IN,
619 dev_name(&pdev->dev));
621 dev_err(&pdev->dev, "cannot request gpio pin %d\n",
627 ret = oxnas_pcie_map_registers(pdev, np, pcie);
629 dev_err(&pdev->dev, "cannot map registers\n");
633 ret = oxnas_pcie_shared_init(pdev, pcie);
637 /* if hw not found, haslink cleared */
638 oxnas_pcie_init_hw(pdev, pcie);
640 if (pcie->haslink && oxnas_pcie_link_up(pcie)) {
642 dev_info(&pdev->dev, "link up\n");
645 dev_info(&pdev->dev, "link down\n");
647 /* should we register our controller even when pcie->haslink is 0 ? */
648 /* register the controller with framework */
649 oxnas_pcie_enable(&pdev->dev, pcie);
654 if (pcie->card_reset)
655 gpio_free(pcie->card_reset);
660 static const struct of_device_id oxnas_pcie_of_match_table[] = {
661 { .compatible = "plxtech,nas782x-pcie", },
665 static struct platform_driver oxnas_pcie_driver = {
667 .name = "oxnas-pcie",
668 .suppress_bind_attrs = true,
669 .of_match_table = oxnas_pcie_of_match_table,
671 .probe = oxnas_pcie_probe,
674 builtin_platform_driver(oxnas_pcie_driver);