1 // SPDX-License-Identifier: GPL-2.0
3 * PCIe host controller driver for Amlogic MESON SoCs
5 * Copyright (c) 2018 Amlogic, inc.
6 * Author: Yue Wang <yue.wang@amlogic.com>
10 #include <linux/delay.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/of_device.h>
13 #include <linux/of_gpio.h>
14 #include <linux/pci.h>
15 #include <linux/platform_device.h>
16 #include <linux/reset.h>
17 #include <linux/resource.h>
18 #include <linux/types.h>
19 #include <linux/phy/phy.h>
20 #include <linux/module.h>
22 #include "pcie-designware.h"
24 #define to_meson_pcie(x) dev_get_drvdata((x)->dev)
26 /* External local bus interface registers */
27 #define PLR_OFFSET 0x700
28 #define PCIE_PORT_LINK_CTRL_OFF (PLR_OFFSET + 0x10)
29 #define FAST_LINK_MODE BIT(7)
30 #define LINK_CAPABLE_MASK GENMASK(21, 16)
31 #define LINK_CAPABLE_X1 BIT(16)
33 #define PCIE_GEN2_CTRL_OFF (PLR_OFFSET + 0x10c)
34 #define NUM_OF_LANES_MASK GENMASK(12, 8)
35 #define NUM_OF_LANES_X1 BIT(8)
36 #define DIRECT_SPEED_CHANGE BIT(17)
38 #define TYPE1_HDR_OFFSET 0x0
39 #define PCIE_STATUS_COMMAND (TYPE1_HDR_OFFSET + 0x04)
40 #define PCI_IO_EN BIT(0)
41 #define PCI_MEM_SPACE_EN BIT(1)
42 #define PCI_BUS_MASTER_EN BIT(2)
44 #define PCIE_BASE_ADDR0 (TYPE1_HDR_OFFSET + 0x10)
45 #define PCIE_BASE_ADDR1 (TYPE1_HDR_OFFSET + 0x14)
47 #define PCIE_CAP_OFFSET 0x70
48 #define PCIE_DEV_CTRL_DEV_STUS (PCIE_CAP_OFFSET + 0x08)
49 #define PCIE_CAP_MAX_PAYLOAD_MASK GENMASK(7, 5)
50 #define PCIE_CAP_MAX_PAYLOAD_SIZE(x) ((x) << 5)
51 #define PCIE_CAP_MAX_READ_REQ_MASK GENMASK(14, 12)
52 #define PCIE_CAP_MAX_READ_REQ_SIZE(x) ((x) << 12)
54 /* PCIe specific config registers */
56 #define APP_LTSSM_ENABLE BIT(7)
58 #define PCIE_CFG_STATUS12 0x30
59 #define IS_SMLH_LINK_UP(x) ((x) & (1 << 6))
60 #define IS_RDLH_LINK_UP(x) ((x) & (1 << 16))
61 #define IS_LTSSM_UP(x) ((((x) >> 10) & 0x1f) == 0x11)
63 #define PCIE_CFG_STATUS17 0x44
64 #define PM_CURRENT_STATE(x) (((x) >> 7) & 0x1)
66 #define WAIT_LINKUP_TIMEOUT 4000
67 #define PORT_CLK_RATE 100000000UL
68 #define MAX_PAYLOAD_SIZE 256
69 #define MAX_READ_REQ_SIZE 256
70 #define PCIE_RESET_DELAY 500
71 #define PCIE_SHARED_RESET 1
72 #define PCIE_NORMAL_RESET 0
81 struct meson_pcie_mem_res {
82 void __iomem *elbi_base;
83 void __iomem *cfg_base;
86 struct meson_pcie_clk_res {
89 struct clk *general_clk;
92 struct meson_pcie_rc_reset {
93 struct reset_control *port;
94 struct reset_control *apb;
99 struct meson_pcie_mem_res mem_res;
100 struct meson_pcie_clk_res clk_res;
101 struct meson_pcie_rc_reset mrst;
102 struct gpio_desc *reset_gpio;
106 static struct reset_control *meson_pcie_get_reset(struct meson_pcie *mp,
110 struct device *dev = mp->pci.dev;
111 struct reset_control *reset;
113 if (reset_type == PCIE_SHARED_RESET)
114 reset = devm_reset_control_get_shared(dev, id);
116 reset = devm_reset_control_get(dev, id);
121 static int meson_pcie_get_resets(struct meson_pcie *mp)
123 struct meson_pcie_rc_reset *mrst = &mp->mrst;
125 mrst->port = meson_pcie_get_reset(mp, "port", PCIE_NORMAL_RESET);
126 if (IS_ERR(mrst->port))
127 return PTR_ERR(mrst->port);
128 reset_control_deassert(mrst->port);
130 mrst->apb = meson_pcie_get_reset(mp, "apb", PCIE_SHARED_RESET);
131 if (IS_ERR(mrst->apb))
132 return PTR_ERR(mrst->apb);
133 reset_control_deassert(mrst->apb);
138 static void __iomem *meson_pcie_get_mem(struct platform_device *pdev,
139 struct meson_pcie *mp,
142 struct device *dev = mp->pci.dev;
143 struct resource *res;
145 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, id);
147 return devm_ioremap_resource(dev, res);
150 static int meson_pcie_get_mems(struct platform_device *pdev,
151 struct meson_pcie *mp)
153 mp->mem_res.elbi_base = meson_pcie_get_mem(pdev, mp, "elbi");
154 if (IS_ERR(mp->mem_res.elbi_base))
155 return PTR_ERR(mp->mem_res.elbi_base);
157 mp->mem_res.cfg_base = meson_pcie_get_mem(pdev, mp, "cfg");
158 if (IS_ERR(mp->mem_res.cfg_base))
159 return PTR_ERR(mp->mem_res.cfg_base);
164 static int meson_pcie_power_on(struct meson_pcie *mp)
168 ret = phy_init(mp->phy);
172 ret = phy_power_on(mp->phy);
181 static void meson_pcie_power_off(struct meson_pcie *mp)
183 phy_power_off(mp->phy);
187 static int meson_pcie_reset(struct meson_pcie *mp)
189 struct meson_pcie_rc_reset *mrst = &mp->mrst;
192 ret = phy_reset(mp->phy);
196 reset_control_assert(mrst->port);
197 reset_control_assert(mrst->apb);
198 udelay(PCIE_RESET_DELAY);
199 reset_control_deassert(mrst->port);
200 reset_control_deassert(mrst->apb);
201 udelay(PCIE_RESET_DELAY);
206 static inline struct clk *meson_pcie_probe_clock(struct device *dev,
207 const char *id, u64 rate)
212 clk = devm_clk_get(dev, id);
217 ret = clk_set_rate(clk, rate);
219 dev_err(dev, "set clk rate failed, ret = %d\n", ret);
224 ret = clk_prepare_enable(clk);
226 dev_err(dev, "couldn't enable clk\n");
230 devm_add_action_or_reset(dev,
231 (void (*) (void *))clk_disable_unprepare,
237 static int meson_pcie_probe_clocks(struct meson_pcie *mp)
239 struct device *dev = mp->pci.dev;
240 struct meson_pcie_clk_res *res = &mp->clk_res;
242 res->port_clk = meson_pcie_probe_clock(dev, "port", PORT_CLK_RATE);
243 if (IS_ERR(res->port_clk))
244 return PTR_ERR(res->port_clk);
246 res->general_clk = meson_pcie_probe_clock(dev, "general", 0);
247 if (IS_ERR(res->general_clk))
248 return PTR_ERR(res->general_clk);
250 res->clk = meson_pcie_probe_clock(dev, "pclk", 0);
251 if (IS_ERR(res->clk))
252 return PTR_ERR(res->clk);
257 static inline void meson_elb_writel(struct meson_pcie *mp, u32 val, u32 reg)
259 writel(val, mp->mem_res.elbi_base + reg);
262 static inline u32 meson_elb_readl(struct meson_pcie *mp, u32 reg)
264 return readl(mp->mem_res.elbi_base + reg);
267 static inline u32 meson_cfg_readl(struct meson_pcie *mp, u32 reg)
269 return readl(mp->mem_res.cfg_base + reg);
272 static inline void meson_cfg_writel(struct meson_pcie *mp, u32 val, u32 reg)
274 writel(val, mp->mem_res.cfg_base + reg);
277 static void meson_pcie_assert_reset(struct meson_pcie *mp)
279 gpiod_set_value_cansleep(mp->reset_gpio, 1);
281 gpiod_set_value_cansleep(mp->reset_gpio, 0);
284 static void meson_pcie_init_dw(struct meson_pcie *mp)
288 val = meson_cfg_readl(mp, PCIE_CFG0);
289 val |= APP_LTSSM_ENABLE;
290 meson_cfg_writel(mp, val, PCIE_CFG0);
292 val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
293 val &= ~(LINK_CAPABLE_MASK | FAST_LINK_MODE);
294 meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
296 val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
297 val |= LINK_CAPABLE_X1;
298 meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
300 val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
301 val &= ~NUM_OF_LANES_MASK;
302 meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
304 val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
305 val |= NUM_OF_LANES_X1 | DIRECT_SPEED_CHANGE;
306 meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
308 meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR0);
309 meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR1);
312 static int meson_size_to_payload(struct meson_pcie *mp, int size)
314 struct device *dev = mp->pci.dev;
317 * dwc supports 2^(val+7) payload size, which val is 0~5 default to 1.
318 * So if input size is not 2^order alignment or less than 2^7 or bigger
319 * than 2^12, just set to default size 2^(1+7).
321 if (!is_power_of_2(size) || size < 128 || size > 4096) {
322 dev_warn(dev, "payload size %d, set to default 256\n", size);
326 return fls(size) - 8;
329 static void meson_set_max_payload(struct meson_pcie *mp, int size)
332 int max_payload_size = meson_size_to_payload(mp, size);
334 val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
335 val &= ~PCIE_CAP_MAX_PAYLOAD_MASK;
336 meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
338 val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
339 val |= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size);
340 meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
343 static void meson_set_max_rd_req_size(struct meson_pcie *mp, int size)
346 int max_rd_req_size = meson_size_to_payload(mp, size);
348 val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
349 val &= ~PCIE_CAP_MAX_READ_REQ_MASK;
350 meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
352 val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
353 val |= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size);
354 meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
357 static inline void meson_enable_memory_space(struct meson_pcie *mp)
359 /* Set the RC Bus Master, Memory Space and I/O Space enables */
360 meson_elb_writel(mp, PCI_IO_EN | PCI_MEM_SPACE_EN | PCI_BUS_MASTER_EN,
361 PCIE_STATUS_COMMAND);
364 static int meson_pcie_establish_link(struct meson_pcie *mp)
366 struct dw_pcie *pci = &mp->pci;
367 struct pcie_port *pp = &pci->pp;
369 meson_pcie_init_dw(mp);
370 meson_set_max_payload(mp, MAX_PAYLOAD_SIZE);
371 meson_set_max_rd_req_size(mp, MAX_READ_REQ_SIZE);
373 dw_pcie_setup_rc(pp);
374 meson_enable_memory_space(mp);
376 meson_pcie_assert_reset(mp);
378 return dw_pcie_wait_for_link(pci);
381 static void meson_pcie_enable_interrupts(struct meson_pcie *mp)
383 if (IS_ENABLED(CONFIG_PCI_MSI))
384 dw_pcie_msi_init(&mp->pci.pp);
387 static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
390 struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
393 ret = dw_pcie_read(pci->dbi_base + where, size, val);
394 if (ret != PCIBIOS_SUCCESSFUL)
398 * There is a bug in the MESON AXG PCIe controller whereby software
399 * cannot program the PCI_CLASS_DEVICE register, so we must fabricate
400 * the return value in the config accessors.
402 if (where == PCI_CLASS_REVISION && size == 4)
403 *val = (PCI_CLASS_BRIDGE_PCI << 16) | (*val & 0xffff);
404 else if (where == PCI_CLASS_DEVICE && size == 2)
405 *val = PCI_CLASS_BRIDGE_PCI;
406 else if (where == PCI_CLASS_DEVICE && size == 1)
407 *val = PCI_CLASS_BRIDGE_PCI & 0xff;
408 else if (where == PCI_CLASS_DEVICE + 1 && size == 1)
409 *val = (PCI_CLASS_BRIDGE_PCI >> 8) & 0xff;
411 return PCIBIOS_SUCCESSFUL;
414 static int meson_pcie_wr_own_conf(struct pcie_port *pp, int where,
417 struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
419 return dw_pcie_write(pci->dbi_base + where, size, val);
422 static int meson_pcie_link_up(struct dw_pcie *pci)
424 struct meson_pcie *mp = to_meson_pcie(pci);
425 struct device *dev = pci->dev;
428 u32 state12, state17, smlh_up, ltssm_up, rdlh_up;
431 state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
432 state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
433 smlh_up = IS_SMLH_LINK_UP(state12);
434 rdlh_up = IS_RDLH_LINK_UP(state12);
435 ltssm_up = IS_LTSSM_UP(state12);
437 if (PM_CURRENT_STATE(state17) < PCIE_GEN3)
441 dev_dbg(dev, "smlh_link_up is on\n");
443 dev_dbg(dev, "rdlh_link_up is on\n");
445 dev_dbg(dev, "ltssm_up is on\n");
447 dev_dbg(dev, "speed_okay\n");
449 if (smlh_up && rdlh_up && ltssm_up && speed_okay)
455 } while (cnt < WAIT_LINKUP_TIMEOUT);
457 dev_err(dev, "error: wait linkup timeout\n");
461 static int meson_pcie_host_init(struct pcie_port *pp)
463 struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
464 struct meson_pcie *mp = to_meson_pcie(pci);
467 ret = meson_pcie_establish_link(mp);
471 meson_pcie_enable_interrupts(mp);
476 static const struct dw_pcie_host_ops meson_pcie_host_ops = {
477 .rd_own_conf = meson_pcie_rd_own_conf,
478 .wr_own_conf = meson_pcie_wr_own_conf,
479 .host_init = meson_pcie_host_init,
482 static int meson_add_pcie_port(struct meson_pcie *mp,
483 struct platform_device *pdev)
485 struct dw_pcie *pci = &mp->pci;
486 struct pcie_port *pp = &pci->pp;
487 struct device *dev = &pdev->dev;
490 if (IS_ENABLED(CONFIG_PCI_MSI)) {
491 pp->msi_irq = platform_get_irq(pdev, 0);
496 pp->ops = &meson_pcie_host_ops;
497 pci->dbi_base = mp->mem_res.elbi_base;
499 ret = dw_pcie_host_init(pp);
501 dev_err(dev, "failed to initialize host\n");
508 static const struct dw_pcie_ops dw_pcie_ops = {
509 .link_up = meson_pcie_link_up,
512 static int meson_pcie_probe(struct platform_device *pdev)
514 struct device *dev = &pdev->dev;
516 struct meson_pcie *mp;
519 mp = devm_kzalloc(dev, sizeof(*mp), GFP_KERNEL);
525 pci->ops = &dw_pcie_ops;
527 mp->phy = devm_phy_get(dev, "pcie");
528 if (IS_ERR(mp->phy)) {
529 dev_err(dev, "get phy failed, %ld\n", PTR_ERR(mp->phy));
530 return PTR_ERR(mp->phy);
533 mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
534 if (IS_ERR(mp->reset_gpio)) {
535 dev_err(dev, "get reset gpio failed\n");
536 return PTR_ERR(mp->reset_gpio);
539 ret = meson_pcie_get_resets(mp);
541 dev_err(dev, "get reset resource failed, %d\n", ret);
545 ret = meson_pcie_get_mems(pdev, mp);
547 dev_err(dev, "get memory resource failed, %d\n", ret);
551 ret = meson_pcie_power_on(mp);
553 dev_err(dev, "phy power on failed, %d\n", ret);
557 ret = meson_pcie_reset(mp);
559 dev_err(dev, "reset failed, %d\n", ret);
563 ret = meson_pcie_probe_clocks(mp);
565 dev_err(dev, "init clock resources failed, %d\n", ret);
569 platform_set_drvdata(pdev, mp);
571 ret = meson_add_pcie_port(mp, pdev);
573 dev_err(dev, "Add PCIe port failed, %d\n", ret);
580 meson_pcie_power_off(mp);
584 static const struct of_device_id meson_pcie_of_match[] = {
586 .compatible = "amlogic,axg-pcie",
589 .compatible = "amlogic,g12a-pcie",
593 MODULE_DEVICE_TABLE(of, meson_pcie_of_match);
595 static struct platform_driver meson_pcie_driver = {
596 .probe = meson_pcie_probe,
598 .name = "meson-pcie",
599 .of_match_table = meson_pcie_of_match,
603 module_platform_driver(meson_pcie_driver);
605 MODULE_AUTHOR("Yue Wang <yue.wang@amlogic.com>");
606 MODULE_DESCRIPTION("Amlogic PCIe Controller driver");
607 MODULE_LICENSE("GPL v2");