2 * Copyright Altera Corporation (C) 2013-2015. All rights reserved
4 * Author: Ley Foon Tan <lftan@altera.com>
5 * Description: Altera PCIe host controller driver
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * You should have received a copy of the GNU General Public License along with
17 * this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <linux/delay.h>
21 #include <linux/interrupt.h>
22 #include <linux/irqchip/chained_irq.h>
23 #include <linux/init.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_pci.h>
27 #include <linux/pci.h>
28 #include <linux/platform_device.h>
29 #include <linux/slab.h>
31 #define RP_TX_REG0 0x2000
32 #define RP_TX_REG1 0x2004
33 #define RP_TX_CNTRL 0x2008
36 #define RP_RXCPL_STATUS 0x2010
37 #define RP_RXCPL_EOP 0x2
38 #define RP_RXCPL_SOP 0x1
39 #define RP_RXCPL_REG0 0x2014
40 #define RP_RXCPL_REG1 0x2018
41 #define P2A_INT_STATUS 0x3060
42 #define P2A_INT_STS_ALL 0xf
43 #define P2A_INT_ENABLE 0x3070
44 #define P2A_INT_ENA_ALL 0xf
45 #define RP_LTSSM 0x3c64
46 #define RP_LTSSM_MASK 0x1f
49 /* TLP configuration type 0 and 1 */
50 #define TLP_FMTTYPE_CFGRD0 0x04 /* Configuration Read Type 0 */
51 #define TLP_FMTTYPE_CFGWR0 0x44 /* Configuration Write Type 0 */
52 #define TLP_FMTTYPE_CFGRD1 0x05 /* Configuration Read Type 1 */
53 #define TLP_FMTTYPE_CFGWR1 0x45 /* Configuration Write Type 1 */
54 #define TLP_PAYLOAD_SIZE 0x01
55 #define TLP_READ_TAG 0x1d
56 #define TLP_WRITE_TAG 0x10
57 #define TLP_CFG_DW0(fmttype) (((fmttype) << 24) | TLP_PAYLOAD_SIZE)
58 #define TLP_CFG_DW1(reqid, tag, be) (((reqid) << 16) | (tag << 8) | (be))
59 #define TLP_CFG_DW2(bus, devfn, offset) \
60 (((bus) << 24) | ((devfn) << 16) | (offset))
61 #define TLP_REQ_ID(bus, devfn) (((bus) << 8) | (devfn))
62 #define TLP_COMP_STATUS(s) (((s) >> 12) & 7)
63 #define TLP_HDR_SIZE 3
67 #define LINK_UP_TIMEOUT 5000
74 struct platform_device *pdev;
75 void __iomem *cra_base;
78 struct irq_domain *irq_domain;
79 struct resource bus_range;
80 struct list_head resources;
83 struct tlp_rp_regpair_t {
89 static inline void cra_writel(struct altera_pcie *pcie, const u32 value,
92 writel_relaxed(value, pcie->cra_base + reg);
95 static inline u32 cra_readl(struct altera_pcie *pcie, const u32 reg)
97 return readl_relaxed(pcie->cra_base + reg);
100 static bool altera_pcie_link_is_up(struct altera_pcie *pcie)
102 return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0);
105 static void altera_pcie_retrain(struct pci_dev *dev)
107 u16 linkcap, linkstat;
108 struct altera_pcie *pcie = dev->bus->sysdata;
111 if (!altera_pcie_link_is_up(pcie))
115 * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
116 * current speed is 2.5 GB/s.
118 pcie_capability_read_word(dev, PCI_EXP_LNKCAP, &linkcap);
120 if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
123 pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
124 if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
125 pcie_capability_set_word(dev, PCI_EXP_LNKCTL,
127 while (!altera_pcie_link_is_up(pcie)) {
129 if (timeout > LINK_UP_TIMEOUT)
135 DECLARE_PCI_FIXUP_EARLY(0x1172, PCI_ANY_ID, altera_pcie_retrain);
138 * Altera PCIe port uses BAR0 of RC's configuration space as the translation
139 * from PCI bus to native BUS. Entire DDR region is mapped into PCIe space
140 * using these registers, so it can be reached by DMA from EP devices.
141 * This BAR0 will also access to MSI vector when receiving MSI/MSIX interrupt
142 * from EP devices, eventually trigger interrupt to GIC. The BAR0 of bridge
143 * should be hidden during enumeration to avoid the sizing and resource
144 * allocation by PCIe core.
146 static bool altera_pcie_hide_rc_bar(struct pci_bus *bus, unsigned int devfn,
149 if (pci_is_root_bus(bus) && (devfn == 0) &&
150 (offset == PCI_BASE_ADDRESS_0))
156 static void tlp_write_tx(struct altera_pcie *pcie,
157 struct tlp_rp_regpair_t *tlp_rp_regdata)
159 cra_writel(pcie, tlp_rp_regdata->reg0, RP_TX_REG0);
160 cra_writel(pcie, tlp_rp_regdata->reg1, RP_TX_REG1);
161 cra_writel(pcie, tlp_rp_regdata->ctrl, RP_TX_CNTRL);
164 static bool altera_pcie_valid_config(struct altera_pcie *pcie,
165 struct pci_bus *bus, int dev)
167 /* If there is no link, then there is no device */
168 if (bus->number != pcie->root_bus_nr) {
169 if (!altera_pcie_link_is_up(pcie))
173 /* access only one slot on each root port */
174 if (bus->number == pcie->root_bus_nr && dev > 0)
178 * Do not read more than one device on the bus directly attached
179 * to root port, root port can only attach to one downstream port.
181 if (bus->primary == pcie->root_bus_nr && dev > 0)
187 static int tlp_read_packet(struct altera_pcie *pcie, u32 *value)
196 * Minimum 2 loops to read TLP headers and 1 loop to read data
199 for (i = 0; i < TLP_LOOP; i++) {
200 ctrl = cra_readl(pcie, RP_RXCPL_STATUS);
201 if ((ctrl & RP_RXCPL_SOP) || (ctrl & RP_RXCPL_EOP) || sop) {
202 reg0 = cra_readl(pcie, RP_RXCPL_REG0);
203 reg1 = cra_readl(pcie, RP_RXCPL_REG1);
205 if (ctrl & RP_RXCPL_SOP) {
207 comp_status = TLP_COMP_STATUS(reg1);
210 if (ctrl & RP_RXCPL_EOP) {
212 return PCIBIOS_DEVICE_NOT_FOUND;
217 return PCIBIOS_SUCCESSFUL;
223 return PCIBIOS_DEVICE_NOT_FOUND;
226 static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
227 u32 data, bool align)
229 struct tlp_rp_regpair_t tlp_rp_regdata;
231 tlp_rp_regdata.reg0 = headers[0];
232 tlp_rp_regdata.reg1 = headers[1];
233 tlp_rp_regdata.ctrl = RP_TX_SOP;
234 tlp_write_tx(pcie, &tlp_rp_regdata);
237 tlp_rp_regdata.reg0 = headers[2];
238 tlp_rp_regdata.reg1 = 0;
239 tlp_rp_regdata.ctrl = 0;
240 tlp_write_tx(pcie, &tlp_rp_regdata);
242 tlp_rp_regdata.reg0 = data;
243 tlp_rp_regdata.reg1 = 0;
245 tlp_rp_regdata.reg0 = headers[2];
246 tlp_rp_regdata.reg1 = data;
249 tlp_rp_regdata.ctrl = RP_TX_EOP;
250 tlp_write_tx(pcie, &tlp_rp_regdata);
253 static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
254 int where, u8 byte_en, u32 *value)
256 u32 headers[TLP_HDR_SIZE];
258 if (bus == pcie->root_bus_nr)
259 headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD0);
261 headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD1);
263 headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN),
264 TLP_READ_TAG, byte_en);
265 headers[2] = TLP_CFG_DW2(bus, devfn, where);
267 tlp_write_packet(pcie, headers, 0, false);
269 return tlp_read_packet(pcie, value);
272 static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
273 int where, u8 byte_en, u32 value)
275 u32 headers[TLP_HDR_SIZE];
278 if (bus == pcie->root_bus_nr)
279 headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR0);
281 headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR1);
283 headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN),
284 TLP_WRITE_TAG, byte_en);
285 headers[2] = TLP_CFG_DW2(bus, devfn, where);
287 /* check alignment to Qword */
288 if ((where & 0x7) == 0)
289 tlp_write_packet(pcie, headers, value, true);
291 tlp_write_packet(pcie, headers, value, false);
293 ret = tlp_read_packet(pcie, NULL);
294 if (ret != PCIBIOS_SUCCESSFUL)
298 * Monitor changes to PCI_PRIMARY_BUS register on root port
299 * and update local copy of root bus number accordingly.
301 if ((bus == pcie->root_bus_nr) && (where == PCI_PRIMARY_BUS))
302 pcie->root_bus_nr = (u8)(value);
304 return PCIBIOS_SUCCESSFUL;
307 static int altera_pcie_cfg_read(struct pci_bus *bus, unsigned int devfn,
308 int where, int size, u32 *value)
310 struct altera_pcie *pcie = bus->sysdata;
315 if (altera_pcie_hide_rc_bar(bus, devfn, where))
316 return PCIBIOS_BAD_REGISTER_NUMBER;
318 if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn))) {
320 return PCIBIOS_DEVICE_NOT_FOUND;
325 byte_en = 1 << (where & 3);
328 byte_en = 3 << (where & 3);
335 ret = tlp_cfg_dword_read(pcie, bus->number, devfn,
336 (where & ~DWORD_MASK), byte_en, &data);
337 if (ret != PCIBIOS_SUCCESSFUL)
342 *value = (data >> (8 * (where & 0x3))) & 0xff;
345 *value = (data >> (8 * (where & 0x2))) & 0xffff;
352 return PCIBIOS_SUCCESSFUL;
355 static int altera_pcie_cfg_write(struct pci_bus *bus, unsigned int devfn,
356 int where, int size, u32 value)
358 struct altera_pcie *pcie = bus->sysdata;
360 u32 shift = 8 * (where & 3);
363 if (altera_pcie_hide_rc_bar(bus, devfn, where))
364 return PCIBIOS_BAD_REGISTER_NUMBER;
366 if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn)))
367 return PCIBIOS_DEVICE_NOT_FOUND;
371 data32 = (value & 0xff) << shift;
372 byte_en = 1 << (where & 3);
375 data32 = (value & 0xffff) << shift;
376 byte_en = 3 << (where & 3);
384 return tlp_cfg_dword_write(pcie, bus->number, devfn,
385 (where & ~DWORD_MASK), byte_en, data32);
388 static struct pci_ops altera_pcie_ops = {
389 .read = altera_pcie_cfg_read,
390 .write = altera_pcie_cfg_write,
393 static int altera_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
394 irq_hw_number_t hwirq)
396 irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
397 irq_set_chip_data(irq, domain->host_data);
402 static const struct irq_domain_ops intx_domain_ops = {
403 .map = altera_pcie_intx_map,
406 static void altera_pcie_isr(struct irq_desc *desc)
408 struct irq_chip *chip = irq_desc_get_chip(desc);
409 struct altera_pcie *pcie;
410 unsigned long status;
414 chained_irq_enter(chip, desc);
415 pcie = irq_desc_get_handler_data(desc);
417 while ((status = cra_readl(pcie, P2A_INT_STATUS)
418 & P2A_INT_STS_ALL) != 0) {
419 for_each_set_bit(bit, &status, INTX_NUM) {
420 /* clear interrupts */
421 cra_writel(pcie, 1 << bit, P2A_INT_STATUS);
423 virq = irq_find_mapping(pcie->irq_domain, bit + 1);
425 generic_handle_irq(virq);
427 dev_err(&pcie->pdev->dev,
428 "unexpected IRQ, INT%d\n", bit);
432 chained_irq_exit(chip, desc);
435 static int altera_pcie_parse_request_of_pci_ranges(struct altera_pcie *pcie)
437 int err, res_valid = 0;
438 struct device *dev = &pcie->pdev->dev;
439 struct device_node *np = dev->of_node;
440 struct resource_entry *win;
442 err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pcie->resources,
447 err = devm_request_pci_bus_resources(dev, &pcie->resources);
449 goto out_release_res;
451 resource_list_for_each_entry(win, &pcie->resources) {
452 struct resource *res = win->res;
454 if (resource_type(res) == IORESOURCE_MEM)
455 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
461 dev_err(dev, "non-prefetchable memory resource required\n");
465 pci_free_resource_list(&pcie->resources);
469 static int altera_pcie_init_irq_domain(struct altera_pcie *pcie)
471 struct device *dev = &pcie->pdev->dev;
472 struct device_node *node = dev->of_node;
475 pcie->irq_domain = irq_domain_add_linear(node, INTX_NUM + 1,
476 &intx_domain_ops, pcie);
477 if (!pcie->irq_domain) {
478 dev_err(dev, "Failed to get a INTx IRQ domain\n");
485 static int altera_pcie_parse_dt(struct altera_pcie *pcie)
487 struct resource *cra;
488 struct platform_device *pdev = pcie->pdev;
490 cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
492 dev_err(&pdev->dev, "no Cra memory resource defined\n");
496 pcie->cra_base = devm_ioremap_resource(&pdev->dev, cra);
497 if (IS_ERR(pcie->cra_base)) {
498 dev_err(&pdev->dev, "failed to map cra memory\n");
499 return PTR_ERR(pcie->cra_base);
503 pcie->irq = platform_get_irq(pdev, 0);
504 if (pcie->irq <= 0) {
505 dev_err(&pdev->dev, "failed to get IRQ: %d\n", pcie->irq);
509 irq_set_chained_handler_and_data(pcie->irq, altera_pcie_isr, pcie);
514 static int altera_pcie_probe(struct platform_device *pdev)
516 struct altera_pcie *pcie;
518 struct pci_bus *child;
521 pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
527 ret = altera_pcie_parse_dt(pcie);
529 dev_err(&pdev->dev, "Parsing DT failed\n");
533 INIT_LIST_HEAD(&pcie->resources);
535 ret = altera_pcie_parse_request_of_pci_ranges(pcie);
537 dev_err(&pdev->dev, "Failed add resources\n");
541 ret = altera_pcie_init_irq_domain(pcie);
543 dev_err(&pdev->dev, "Failed creating IRQ Domain\n");
547 /* clear all interrupts */
548 cra_writel(pcie, P2A_INT_STS_ALL, P2A_INT_STATUS);
549 /* enable all interrupts */
550 cra_writel(pcie, P2A_INT_ENA_ALL, P2A_INT_ENABLE);
552 bus = pci_scan_root_bus(&pdev->dev, pcie->root_bus_nr, &altera_pcie_ops,
553 pcie, &pcie->resources);
557 pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
558 pci_assign_unassigned_bus_resources(bus);
560 /* Configure PCI Express setting. */
561 list_for_each_entry(child, &bus->children, node)
562 pcie_bus_configure_settings(child);
564 pci_bus_add_devices(bus);
566 platform_set_drvdata(pdev, pcie);
570 static const struct of_device_id altera_pcie_of_match[] = {
571 { .compatible = "altr,pcie-root-port-1.0", },
575 static struct platform_driver altera_pcie_driver = {
576 .probe = altera_pcie_probe,
578 .name = "altera-pcie",
579 .of_match_table = altera_pcie_of_match,
580 .suppress_bind_attrs = true,
584 static int altera_pcie_init(void)
586 return platform_driver_register(&altera_pcie_driver);
588 device_initcall(altera_pcie_init);