1 files changed, 492 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
new file mode 100644
index 000000000..c1527693b
--- /dev/null
+++ b/drivers/pci/controller/dwc/pci-meson.c
@@ -0,0 +1,492 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Amlogic MESON SoCs
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yue Wang <yue.wang@amlogic.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/resource.h>
+#include <linux/types.h>
+#include <linux/phy/phy.h>
+#include <linux/module.h>
+
+#include "pcie-designware.h"
+
+#define to_meson_pcie(x) dev_get_drvdata((x)->dev)
+
+#define PCIE_CAP_MAX_PAYLOAD_SIZE(x)	((x) << 5)
+#define PCIE_CAP_MAX_READ_REQ_SIZE(x)	((x) << 12)
+
+/* PCIe specific config registers */
+#define PCIE_CFG0			0x0
+#define APP_LTSSM_ENABLE		BIT(7)
+
+#define PCIE_CFG_STATUS12		0x30
+#define IS_SMLH_LINK_UP(x)		((x) & (1 << 6))
+#define IS_RDLH_LINK_UP(x)		((x) & (1 << 16))
+#define IS_LTSSM_UP(x)			((((x) >> 10) & 0x1f) == 0x11)
+
+#define PCIE_CFG_STATUS17		0x44
+#define PM_CURRENT_STATE(x)		(((x) >> 7) & 0x1)
+
+#define WAIT_LINKUP_TIMEOUT		4000
+#define PORT_CLK_RATE			100000000UL
+#define MAX_PAYLOAD_SIZE		256
+#define MAX_READ_REQ_SIZE		256
+#define PCIE_RESET_DELAY		500
+#define PCIE_SHARED_RESET		1
+#define PCIE_NORMAL_RESET		0
+
+enum pcie_data_rate {
+	PCIE_GEN1,
+	PCIE_GEN2,
+	PCIE_GEN3,
+	PCIE_GEN4
+};
+
+struct meson_pcie_clk_res {
+	struct clk *clk;
+	struct clk *port_clk;
+	struct clk *general_clk;
+};
+
+struct meson_pcie_rc_reset {
+	struct reset_control *port;
+	struct reset_control *apb;
+};
+
+struct meson_pcie {
+	struct dw_pcie pci;
+	void __iomem *cfg_base;
+	struct meson_pcie_clk_res clk_res;
+	struct meson_pcie_rc_reset mrst;
+	struct gpio_desc *reset_gpio;
+	struct phy *phy;
+};
+
+static struct reset_control *meson_pcie_get_reset(struct meson_pcie *mp,
+						  const char *id,
+						  u32 reset_type)
+{
+	struct device *dev = mp->pci.dev;
+	struct reset_control *reset;
+
+	if (reset_type == PCIE_SHARED_RESET)
+		reset = devm_reset_control_get_shared(dev, id);
+	else
+		reset = devm_reset_control_get(dev, id);
+
+	return reset;
+}
+
+static int meson_pcie_get_resets(struct meson_pcie *mp)
+{
+	struct meson_pcie_rc_reset *mrst = &mp->mrst;
+
+	mrst->port = meson_pcie_get_reset(mp, "port", PCIE_NORMAL_RESET);
+	if (IS_ERR(mrst->port))
+		return PTR_ERR(mrst->port);
+	reset_control_deassert(mrst->port);
+
+	mrst->apb = meson_pcie_get_reset(mp, "apb", PCIE_SHARED_RESET);
+	if (IS_ERR(mrst->apb))
+		return PTR_ERR(mrst->apb);
+	reset_control_deassert(mrst->apb);
+
+	return 0;
+}
+
+static int meson_pcie_get_mems(struct platform_device *pdev,
+			       struct meson_pcie *mp)
+{
+	struct dw_pcie *pci = &mp->pci;
+
+	pci->dbi_base = devm_platform_ioremap_resource_byname(pdev, "elbi");
+	if (IS_ERR(pci->dbi_base))
+		return PTR_ERR(pci->dbi_base);
+
+	mp->cfg_base = devm_platform_ioremap_resource_byname(pdev, "cfg");
+	if (IS_ERR(mp->cfg_base))
+		return PTR_ERR(mp->cfg_base);
+
+	return 0;
+}
+
+static int meson_pcie_power_on(struct meson_pcie *mp)
+{
+	int ret = 0;
+
+	ret = phy_init(mp->phy);
+	if (ret)
+		return ret;
+
+	ret = phy_power_on(mp->phy);
+	if (ret) {
+		phy_exit(mp->phy);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void meson_pcie_power_off(struct meson_pcie *mp)
+{
+	phy_power_off(mp->phy);
+	phy_exit(mp->phy);
+}
+
+static int meson_pcie_reset(struct meson_pcie *mp)
+{
+	struct meson_pcie_rc_reset *mrst = &mp->mrst;
+	int ret = 0;
+
+	ret = phy_reset(mp->phy);
+	if (ret)
+		return ret;
+
+	reset_control_assert(mrst->port);
+	reset_control_assert(mrst->apb);
+	udelay(PCIE_RESET_DELAY);
+	reset_control_deassert(mrst->port);
+	reset_control_deassert(mrst->apb);
+	udelay(PCIE_RESET_DELAY);
+
+	return 0;
+}
+
+static inline struct clk *meson_pcie_probe_clock(struct device *dev,
+						 const char *id, u64 rate)
+{
+	struct clk *clk;
+	int ret;
+
+	clk = devm_clk_get(dev, id);
+	if (IS_ERR(clk))
+		return clk;
+
+	if (rate) {
+		ret = clk_set_rate(clk, rate);
+		if (ret) {
+			dev_err(dev, "set clk rate failed, ret = %d\n", ret);
+			return ERR_PTR(ret);
+		}
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(dev, "couldn't enable clk\n");
+		return ERR_PTR(ret);
+	}
+
+	devm_add_action_or_reset(dev,
+				 (void (*) (void *))clk_disable_unprepare,
+				 clk);
+
+	return clk;
+}
+
+static int meson_pcie_probe_clocks(struct meson_pcie *mp)
+{
+	struct device *dev = mp->pci.dev;
+	struct meson_pcie_clk_res *res = &mp->clk_res;
+
+	res->port_clk = meson_pcie_probe_clock(dev, "port", PORT_CLK_RATE);
+	if (IS_ERR(res->port_clk))
+		return PTR_ERR(res->port_clk);
+
+	res->general_clk = meson_pcie_probe_clock(dev, "general", 0);
+	if (IS_ERR(res->general_clk))
+		return PTR_ERR(res->general_clk);
+
+	res->clk = meson_pcie_probe_clock(dev, "pclk", 0);
+	if (IS_ERR(res->clk))
+		return PTR_ERR(res->clk);
+
+	return 0;
+}
+
+static inline u32 meson_cfg_readl(struct meson_pcie *mp, u32 reg)
+{
+	return readl(mp->cfg_base + reg);
+}
+
+static inline void meson_cfg_writel(struct meson_pcie *mp, u32 val, u32 reg)
+{
+	writel(val, mp->cfg_base + reg);
+}
+
+static void meson_pcie_assert_reset(struct meson_pcie *mp)
+{
+	gpiod_set_value_cansleep(mp->reset_gpio, 1);
+	udelay(500);
+	gpiod_set_value_cansleep(mp->reset_gpio, 0);
+}
+
+static void meson_pcie_ltssm_enable(struct meson_pcie *mp)
+{
+	u32 val;
+
+	val = meson_cfg_readl(mp, PCIE_CFG0);
+	val |= APP_LTSSM_ENABLE;
+	meson_cfg_writel(mp, val, PCIE_CFG0);
+}
+
+static int meson_size_to_payload(struct meson_pcie *mp, int size)
+{
+	struct device *dev = mp->pci.dev;
+
+	/*
+	 * dwc supports 2^(val+7) payload size, which val is 0~5 default to 1.
+	 * So if input size is not 2^order alignment or less than 2^7 or bigger
+	 * than 2^12, just set to default size 2^(1+7).
+	 */
+	if (!is_power_of_2(size) || size < 128 || size > 4096) {
+		dev_warn(dev, "payload size %d, set to default 256\n", size);
+		return 1;
+	}
+
+	return fls(size) - 8;
+}
+
+static void meson_set_max_payload(struct meson_pcie *mp, int size)
+{
+	struct dw_pcie *pci = &mp->pci;
+	u32 val;
+	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	int max_payload_size = meson_size_to_payload(mp, size);
+
+	val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL);
+	val &= ~PCI_EXP_DEVCTL_PAYLOAD;
+	dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val);
+
+	val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL);
+	val |= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size);
+	dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val);
+}
+
+static void meson_set_max_rd_req_size(struct meson_pcie *mp, int size)
+{
+	struct dw_pcie *pci = &mp->pci;
+	u32 val;
+	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	int max_rd_req_size = meson_size_to_payload(mp, size);
+
+	val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL);
+	val &= ~PCI_EXP_DEVCTL_READRQ;
+	dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val);
+
+	val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL);
+	val |= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size);
+	dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val);
+}
+
+static int meson_pcie_start_link(struct dw_pcie *pci)
+{
+	struct meson_pcie *mp = to_meson_pcie(pci);
+
+	meson_pcie_ltssm_enable(mp);
+	meson_pcie_assert_reset(mp);
+
+	return 0;
+}
+
+static int meson_pcie_rd_own_conf(struct pci_bus *bus, u32 devfn,
+				  int where, int size, u32 *val)
+{
+	int ret;
+
+	ret = pci_generic_config_read(bus, devfn, where, size, val);
+	if (ret != PCIBIOS_SUCCESSFUL)
+		return ret;
+
+	/*
+	 * There is a bug in the MESON AXG PCIe controller whereby software
+	 * cannot program the PCI_CLASS_DEVICE register, so we must fabricate
+	 * the return value in the config accessors.
+	 */
+	if ((where & ~3) == PCI_CLASS_REVISION) {
+		if (size <= 2)
+			*val = (*val & ((1 << (size * 8)) - 1)) << (8 * (where & 3));
+		*val &= ~0xffffff00;
+		*val |= PCI_CLASS_BRIDGE_PCI_NORMAL << 8;
+		if (size <= 2)
+			*val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops meson_pci_ops = {
+	.map_bus = dw_pcie_own_conf_map_bus,
+	.read = meson_pcie_rd_own_conf,
+	.write = pci_generic_config_write,
+};
+
+static int meson_pcie_link_up(struct dw_pcie *pci)
+{
+	struct meson_pcie *mp = to_meson_pcie(pci);
+	struct device *dev = pci->dev;
+	u32 speed_okay = 0;
+	u32 cnt = 0;
+	u32 state12, state17, smlh_up, ltssm_up, rdlh_up;
+
+	do {
+		state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
+		state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
+		smlh_up = IS_SMLH_LINK_UP(state12);
+		rdlh_up = IS_RDLH_LINK_UP(state12);
+		ltssm_up = IS_LTSSM_UP(state12);
+
+		if (PM_CURRENT_STATE(state17) < PCIE_GEN3)
+			speed_okay = 1;
+
+		if (smlh_up)
+			dev_dbg(dev, "smlh_link_up is on\n");
+		if (rdlh_up)
+			dev_dbg(dev, "rdlh_link_up is on\n");
+		if (ltssm_up)
+			dev_dbg(dev, "ltssm_up is on\n");
+		if (speed_okay)
+			dev_dbg(dev, "speed_okay\n");
+
+		if (smlh_up && rdlh_up && ltssm_up && speed_okay)
+			return 1;
+
+		cnt++;
+
+		udelay(10);
+	} while (cnt < WAIT_LINKUP_TIMEOUT);
+
+	dev_err(dev, "error: wait linkup timeout\n");
+	return 0;
+}
+
+static int meson_pcie_host_init(struct dw_pcie_rp *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct meson_pcie *mp = to_meson_pcie(pci);
+
+	pp->bridge->ops = &meson_pci_ops;
+
+	meson_set_max_payload(mp, MAX_PAYLOAD_SIZE);
+	meson_set_max_rd_req_size(mp, MAX_READ_REQ_SIZE);
+
+	return 0;
+}
+
+static const struct dw_pcie_host_ops meson_pcie_host_ops = {
+	.host_init = meson_pcie_host_init,
+};
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.link_up = meson_pcie_link_up,
+	.start_link = meson_pcie_start_link,
+};
+
+static int meson_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct dw_pcie *pci;
+	struct meson_pcie *mp;
+	int ret;
+
+	mp = devm_kzalloc(dev, sizeof(*mp), GFP_KERNEL);
+	if (!mp)
+		return -ENOMEM;
+
+	pci = &mp->pci;
+	pci->dev = dev;
+	pci->ops = &dw_pcie_ops;
+	pci->pp.ops = &meson_pcie_host_ops;
+	pci->num_lanes = 1;
+
+	mp->phy = devm_phy_get(dev, "pcie");
+	if (IS_ERR(mp->phy)) {
+		dev_err(dev, "get phy failed, %ld\n", PTR_ERR(mp->phy));
+		return PTR_ERR(mp->phy);
+	}
+
+	mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(mp->reset_gpio)) {
+		dev_err(dev, "get reset gpio failed\n");
+		return PTR_ERR(mp->reset_gpio);
+	}
+
+	ret = meson_pcie_get_resets(mp);
+	if (ret) {
+		dev_err(dev, "get reset resource failed, %d\n", ret);
+		return ret;
+	}
+
+	ret = meson_pcie_get_mems(pdev, mp);
+	if (ret) {
+		dev_err(dev, "get memory resource failed, %d\n", ret);
+		return ret;
+	}
+
+	ret = meson_pcie_power_on(mp);
+	if (ret) {
+		dev_err(dev, "phy power on failed, %d\n", ret);
+		return ret;
+	}
+
+	ret = meson_pcie_reset(mp);
+	if (ret) {
+		dev_err(dev, "reset failed, %d\n", ret);
+		goto err_phy;
+	}
+
+	ret = meson_pcie_probe_clocks(mp);
+	if (ret) {
+		dev_err(dev, "init clock resources failed, %d\n", ret);
+		goto err_phy;
+	}
+
+	platform_set_drvdata(pdev, mp);
+
+	ret = dw_pcie_host_init(&pci->pp);
+	if (ret < 0) {
+		dev_err(dev, "Add PCIe port failed, %d\n", ret);
+		goto err_phy;
+	}
+
+	return 0;
+
+err_phy:
+	meson_pcie_power_off(mp);
+	return ret;
+}
+
+static const struct of_device_id meson_pcie_of_match[] = {
+	{
+		.compatible = "amlogic,axg-pcie",
+	},
+	{
+		.compatible = "amlogic,g12a-pcie",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, meson_pcie_of_match);
+
+static struct platform_driver meson_pcie_driver = {
+	.probe = meson_pcie_probe,
+	.driver = {
+		.name = "meson-pcie",
+		.of_match_table = meson_pcie_of_match,
+	},
+};
+
+module_platform_driver(meson_pcie_driver);
+
+MODULE_AUTHOR("Yue Wang <yue.wang@amlogic.com>");
+MODULE_DESCRIPTION("Amlogic PCIe Controller driver");
+MODULE_LICENSE("GPL v2");