2 * Copyright Altera Corporation (C) 2013-2015. All rights reserved
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * You should have received a copy of the GNU General Public License along with
14 * this program. If not, see <http://www.gnu.org/licenses/>.
17 #include <linux/delay.h>
18 #include <linux/interrupt.h>
19 #include <linux/irqchip/chained_irq.h>
20 #include <linux/module.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23 #include <linux/of_pci.h>
24 #include <linux/pci.h>
25 #include <linux/platform_device.h>
26 #include <linux/slab.h>
28 #define RP_TX_REG0 0x2000
29 #define RP_TX_REG1 0x2004
30 #define RP_TX_CNTRL 0x2008
33 #define RP_RXCPL_STATUS 0x2010
34 #define RP_RXCPL_EOP 0x2
35 #define RP_RXCPL_SOP 0x1
36 #define RP_RXCPL_REG0 0x2014
37 #define RP_RXCPL_REG1 0x2018
38 #define P2A_INT_STATUS 0x3060
39 #define P2A_INT_STS_ALL 0xf
40 #define P2A_INT_ENABLE 0x3070
41 #define P2A_INT_ENA_ALL 0xf
42 #define RP_LTSSM 0x3c64
43 #define RP_LTSSM_MASK 0x1f
46 #define PCIE_CAP_OFFSET 0x80
47 /* TLP configuration type 0 and 1 */
48 #define TLP_FMTTYPE_CFGRD0 0x04 /* Configuration Read Type 0 */
49 #define TLP_FMTTYPE_CFGWR0 0x44 /* Configuration Write Type 0 */
50 #define TLP_FMTTYPE_CFGRD1 0x05 /* Configuration Read Type 1 */
51 #define TLP_FMTTYPE_CFGWR1 0x45 /* Configuration Write Type 1 */
52 #define TLP_PAYLOAD_SIZE 0x01
53 #define TLP_READ_TAG 0x1d
54 #define TLP_WRITE_TAG 0x10
55 #define TLP_CFG_DW0(fmttype) (((fmttype) << 24) | TLP_PAYLOAD_SIZE)
56 #define TLP_CFG_DW1(reqid, tag, be) (((reqid) << 16) | (tag << 8) | (be))
57 #define TLP_CFG_DW2(bus, devfn, offset) \
58 (((bus) << 24) | ((devfn) << 16) | (offset))
59 #define TLP_REQ_ID(bus, devfn) (((bus) << 8) | (devfn))
60 #define TLP_COMP_STATUS(s) (((s) >> 12) & 7)
61 #define TLP_HDR_SIZE 3
65 #define LINK_UP_TIMEOUT HZ
66 #define LINK_RETRAIN_TIMEOUT HZ
73 struct platform_device *pdev;
74 void __iomem *cra_base;
77 struct irq_domain *irq_domain;
78 struct resource bus_range;
79 struct list_head resources;
82 struct tlp_rp_regpair_t {
88 static inline void cra_writel(struct altera_pcie *pcie, const u32 value,
91 writel_relaxed(value, pcie->cra_base + reg);
94 static inline u32 cra_readl(struct altera_pcie *pcie, const u32 reg)
96 return readl_relaxed(pcie->cra_base + reg);
99 static bool altera_pcie_link_is_up(struct altera_pcie *pcie)
101 return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0);
105 * Altera PCIe port uses BAR0 of RC's configuration space as the translation
106 * from PCI bus to native BUS. Entire DDR region is mapped into PCIe space
107 * using these registers, so it can be reached by DMA from EP devices.
108 * This BAR0 will also access to MSI vector when receiving MSI/MSIX interrupt
109 * from EP devices, eventually trigger interrupt to GIC. The BAR0 of bridge
110 * should be hidden during enumeration to avoid the sizing and resource
111 * allocation by PCIe core.
113 static bool altera_pcie_hide_rc_bar(struct pci_bus *bus, unsigned int devfn,
116 if (pci_is_root_bus(bus) && (devfn == 0) &&
117 (offset == PCI_BASE_ADDRESS_0))
123 static void tlp_write_tx(struct altera_pcie *pcie,
124 struct tlp_rp_regpair_t *tlp_rp_regdata)
126 cra_writel(pcie, tlp_rp_regdata->reg0, RP_TX_REG0);
127 cra_writel(pcie, tlp_rp_regdata->reg1, RP_TX_REG1);
128 cra_writel(pcie, tlp_rp_regdata->ctrl, RP_TX_CNTRL);
131 static bool altera_pcie_valid_config(struct altera_pcie *pcie,
132 struct pci_bus *bus, int dev)
134 /* If there is no link, then there is no device */
135 if (bus->number != pcie->root_bus_nr) {
136 if (!altera_pcie_link_is_up(pcie))
140 /* access only one slot on each root port */
141 if (bus->number == pcie->root_bus_nr && dev > 0)
145 * Do not read more than one device on the bus directly attached
146 * to root port, root port can only attach to one downstream port.
148 if (bus->primary == pcie->root_bus_nr && dev > 0)
154 static int tlp_read_packet(struct altera_pcie *pcie, u32 *value)
163 * Minimum 2 loops to read TLP headers and 1 loop to read data
166 for (i = 0; i < TLP_LOOP; i++) {
167 ctrl = cra_readl(pcie, RP_RXCPL_STATUS);
168 if ((ctrl & RP_RXCPL_SOP) || (ctrl & RP_RXCPL_EOP) || sop) {
169 reg0 = cra_readl(pcie, RP_RXCPL_REG0);
170 reg1 = cra_readl(pcie, RP_RXCPL_REG1);
172 if (ctrl & RP_RXCPL_SOP) {
174 comp_status = TLP_COMP_STATUS(reg1);
177 if (ctrl & RP_RXCPL_EOP) {
179 return PCIBIOS_DEVICE_NOT_FOUND;
184 return PCIBIOS_SUCCESSFUL;
190 return PCIBIOS_DEVICE_NOT_FOUND;
193 static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
194 u32 data, bool align)
196 struct tlp_rp_regpair_t tlp_rp_regdata;
198 tlp_rp_regdata.reg0 = headers[0];
199 tlp_rp_regdata.reg1 = headers[1];
200 tlp_rp_regdata.ctrl = RP_TX_SOP;
201 tlp_write_tx(pcie, &tlp_rp_regdata);
204 tlp_rp_regdata.reg0 = headers[2];
205 tlp_rp_regdata.reg1 = 0;
206 tlp_rp_regdata.ctrl = 0;
207 tlp_write_tx(pcie, &tlp_rp_regdata);
209 tlp_rp_regdata.reg0 = data;
210 tlp_rp_regdata.reg1 = 0;
212 tlp_rp_regdata.reg0 = headers[2];
213 tlp_rp_regdata.reg1 = data;
216 tlp_rp_regdata.ctrl = RP_TX_EOP;
217 tlp_write_tx(pcie, &tlp_rp_regdata);
220 static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
221 int where, u8 byte_en, u32 *value)
223 u32 headers[TLP_HDR_SIZE];
225 if (bus == pcie->root_bus_nr)
226 headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD0);
228 headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD1);
230 headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN),
231 TLP_READ_TAG, byte_en);
232 headers[2] = TLP_CFG_DW2(bus, devfn, where);
234 tlp_write_packet(pcie, headers, 0, false);
236 return tlp_read_packet(pcie, value);
239 static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
240 int where, u8 byte_en, u32 value)
242 u32 headers[TLP_HDR_SIZE];
245 if (bus == pcie->root_bus_nr)
246 headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR0);
248 headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR1);
250 headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, RP_DEVFN),
251 TLP_WRITE_TAG, byte_en);
252 headers[2] = TLP_CFG_DW2(bus, devfn, where);
254 /* check alignment to Qword */
255 if ((where & 0x7) == 0)
256 tlp_write_packet(pcie, headers, value, true);
258 tlp_write_packet(pcie, headers, value, false);
260 ret = tlp_read_packet(pcie, NULL);
261 if (ret != PCIBIOS_SUCCESSFUL)
265 * Monitor changes to PCI_PRIMARY_BUS register on root port
266 * and update local copy of root bus number accordingly.
268 if ((bus == pcie->root_bus_nr) && (where == PCI_PRIMARY_BUS))
269 pcie->root_bus_nr = (u8)(value);
271 return PCIBIOS_SUCCESSFUL;
274 static int _altera_pcie_cfg_read(struct altera_pcie *pcie, u8 busno,
275 unsigned int devfn, int where, int size,
284 byte_en = 1 << (where & 3);
287 byte_en = 3 << (where & 3);
294 ret = tlp_cfg_dword_read(pcie, busno, devfn,
295 (where & ~DWORD_MASK), byte_en, &data);
296 if (ret != PCIBIOS_SUCCESSFUL)
301 *value = (data >> (8 * (where & 0x3))) & 0xff;
304 *value = (data >> (8 * (where & 0x2))) & 0xffff;
311 return PCIBIOS_SUCCESSFUL;
314 static int _altera_pcie_cfg_write(struct altera_pcie *pcie, u8 busno,
315 unsigned int devfn, int where, int size,
319 u32 shift = 8 * (where & 3);
324 data32 = (value & 0xff) << shift;
325 byte_en = 1 << (where & 3);
328 data32 = (value & 0xffff) << shift;
329 byte_en = 3 << (where & 3);
337 return tlp_cfg_dword_write(pcie, busno, devfn, (where & ~DWORD_MASK),
341 static int altera_pcie_cfg_read(struct pci_bus *bus, unsigned int devfn,
342 int where, int size, u32 *value)
344 struct altera_pcie *pcie = bus->sysdata;
346 if (altera_pcie_hide_rc_bar(bus, devfn, where))
347 return PCIBIOS_BAD_REGISTER_NUMBER;
349 if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn))) {
351 return PCIBIOS_DEVICE_NOT_FOUND;
354 return _altera_pcie_cfg_read(pcie, bus->number, devfn, where, size,
358 static int altera_pcie_cfg_write(struct pci_bus *bus, unsigned int devfn,
359 int where, int size, u32 value)
361 struct altera_pcie *pcie = bus->sysdata;
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;
369 return _altera_pcie_cfg_write(pcie, bus->number, devfn, where, size,
373 static struct pci_ops altera_pcie_ops = {
374 .read = altera_pcie_cfg_read,
375 .write = altera_pcie_cfg_write,
378 static int altera_read_cap_word(struct altera_pcie *pcie, u8 busno,
379 unsigned int devfn, int offset, u16 *value)
384 ret = _altera_pcie_cfg_read(pcie, busno, devfn,
385 PCIE_CAP_OFFSET + offset, sizeof(*value),
391 static int altera_write_cap_word(struct altera_pcie *pcie, u8 busno,
392 unsigned int devfn, int offset, u16 value)
394 return _altera_pcie_cfg_write(pcie, busno, devfn,
395 PCIE_CAP_OFFSET + offset, sizeof(value),
399 static void altera_wait_link_retrain(struct altera_pcie *pcie)
402 unsigned long start_jiffies;
404 /* Wait for link training end. */
405 start_jiffies = jiffies;
407 altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
408 PCI_EXP_LNKSTA, ®16);
409 if (!(reg16 & PCI_EXP_LNKSTA_LT))
412 if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) {
413 dev_err(&pcie->pdev->dev, "link retrain timeout\n");
419 /* Wait for link is up */
420 start_jiffies = jiffies;
422 if (altera_pcie_link_is_up(pcie))
425 if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) {
426 dev_err(&pcie->pdev->dev, "link up timeout\n");
433 static void altera_pcie_retrain(struct altera_pcie *pcie)
435 u16 linkcap, linkstat, linkctl;
437 if (!altera_pcie_link_is_up(pcie))
441 * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
442 * current speed is 2.5 GB/s.
444 altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN, PCI_EXP_LNKCAP,
446 if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
449 altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN, PCI_EXP_LNKSTA,
451 if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
452 altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
453 PCI_EXP_LNKCTL, &linkctl);
454 linkctl |= PCI_EXP_LNKCTL_RL;
455 altera_write_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
456 PCI_EXP_LNKCTL, linkctl);
458 altera_wait_link_retrain(pcie);
462 static int altera_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
463 irq_hw_number_t hwirq)
465 irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
466 irq_set_chip_data(irq, domain->host_data);
471 static const struct irq_domain_ops intx_domain_ops = {
472 .map = altera_pcie_intx_map,
475 static void altera_pcie_isr(struct irq_desc *desc)
477 struct irq_chip *chip = irq_desc_get_chip(desc);
478 struct altera_pcie *pcie;
479 unsigned long status;
483 chained_irq_enter(chip, desc);
484 pcie = irq_desc_get_handler_data(desc);
486 while ((status = cra_readl(pcie, P2A_INT_STATUS)
487 & P2A_INT_STS_ALL) != 0) {
488 for_each_set_bit(bit, &status, INTX_NUM) {
489 /* clear interrupts */
490 cra_writel(pcie, 1 << bit, P2A_INT_STATUS);
492 virq = irq_find_mapping(pcie->irq_domain, bit + 1);
494 generic_handle_irq(virq);
496 dev_err(&pcie->pdev->dev,
497 "unexpected IRQ, INT%d\n", bit);
501 chained_irq_exit(chip, desc);
504 static void altera_pcie_release_of_pci_ranges(struct altera_pcie *pcie)
506 pci_free_resource_list(&pcie->resources);
509 static int altera_pcie_parse_request_of_pci_ranges(struct altera_pcie *pcie)
511 int err, res_valid = 0;
512 struct device *dev = &pcie->pdev->dev;
513 struct device_node *np = dev->of_node;
514 struct resource_entry *win;
516 err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pcie->resources,
521 resource_list_for_each_entry(win, &pcie->resources) {
522 struct resource *parent, *res = win->res;
524 switch (resource_type(res)) {
526 parent = &iomem_resource;
527 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
533 err = devm_request_resource(dev, parent, res);
535 goto out_release_res;
539 dev_err(dev, "non-prefetchable memory resource required\n");
541 goto out_release_res;
547 altera_pcie_release_of_pci_ranges(pcie);
551 static int altera_pcie_init_irq_domain(struct altera_pcie *pcie)
553 struct device *dev = &pcie->pdev->dev;
554 struct device_node *node = dev->of_node;
557 pcie->irq_domain = irq_domain_add_linear(node, INTX_NUM + 1,
558 &intx_domain_ops, pcie);
559 if (!pcie->irq_domain) {
560 dev_err(dev, "Failed to get a INTx IRQ domain\n");
567 static int altera_pcie_parse_dt(struct altera_pcie *pcie)
569 struct resource *cra;
570 struct platform_device *pdev = pcie->pdev;
572 cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
574 dev_err(&pdev->dev, "no Cra memory resource defined\n");
578 pcie->cra_base = devm_ioremap_resource(&pdev->dev, cra);
579 if (IS_ERR(pcie->cra_base)) {
580 dev_err(&pdev->dev, "failed to map cra memory\n");
581 return PTR_ERR(pcie->cra_base);
585 pcie->irq = platform_get_irq(pdev, 0);
586 if (pcie->irq <= 0) {
587 dev_err(&pdev->dev, "failed to get IRQ: %d\n", pcie->irq);
591 irq_set_chained_handler_and_data(pcie->irq, altera_pcie_isr, pcie);
596 static void altera_pcie_host_init(struct altera_pcie *pcie)
598 altera_pcie_retrain(pcie);
601 static int altera_pcie_probe(struct platform_device *pdev)
603 struct altera_pcie *pcie;
605 struct pci_bus *child;
608 pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
614 ret = altera_pcie_parse_dt(pcie);
616 dev_err(&pdev->dev, "Parsing DT failed\n");
620 INIT_LIST_HEAD(&pcie->resources);
622 ret = altera_pcie_parse_request_of_pci_ranges(pcie);
624 dev_err(&pdev->dev, "Failed add resources\n");
628 ret = altera_pcie_init_irq_domain(pcie);
630 dev_err(&pdev->dev, "Failed creating IRQ Domain\n");
634 /* clear all interrupts */
635 cra_writel(pcie, P2A_INT_STS_ALL, P2A_INT_STATUS);
636 /* enable all interrupts */
637 cra_writel(pcie, P2A_INT_ENA_ALL, P2A_INT_ENABLE);
638 altera_pcie_host_init(pcie);
640 bus = pci_scan_root_bus(&pdev->dev, pcie->root_bus_nr, &altera_pcie_ops,
641 pcie, &pcie->resources);
645 pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
646 pci_assign_unassigned_bus_resources(bus);
648 /* Configure PCI Express setting. */
649 list_for_each_entry(child, &bus->children, node)
650 pcie_bus_configure_settings(child);
652 pci_bus_add_devices(bus);
654 platform_set_drvdata(pdev, pcie);
658 static const struct of_device_id altera_pcie_of_match[] = {
659 { .compatible = "altr,pcie-root-port-1.0", },
662 MODULE_DEVICE_TABLE(of, altera_pcie_of_match);
664 static struct platform_driver altera_pcie_driver = {
665 .probe = altera_pcie_probe,
667 .name = "altera-pcie",
668 .of_match_table = altera_pcie_of_match,
669 .suppress_bind_attrs = true,
673 static int altera_pcie_init(void)
675 return platform_driver_register(&altera_pcie_driver);
677 module_init(altera_pcie_init);
679 MODULE_AUTHOR("Ley Foon Tan <lftan@altera.com>");
680 MODULE_DESCRIPTION("Altera PCIe host controller driver");
681 MODULE_LICENSE("GPL v2");