[PATCH v3 2/2] phy: bcm-sr-pcie: Add Stingray PCIe PHY driver

From: Ray Jui
Date: Wed Jul 04 2018 - 14:22:51 EST


Add Stingray PCIe PHY driver for both PAXB and PAXC root complex

Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
---
drivers/phy/broadcom/Kconfig | 10 +
drivers/phy/broadcom/Makefile | 2 +
drivers/phy/broadcom/phy-bcm-sr-pcie.c | 327 +++++++++++++++++++++++++++++++++
3 files changed, 339 insertions(+)
create mode 100644 drivers/phy/broadcom/phy-bcm-sr-pcie.c

diff --git a/drivers/phy/broadcom/Kconfig b/drivers/phy/broadcom/Kconfig
index 97d27b0d5..8786a96 100644
--- a/drivers/phy/broadcom/Kconfig
+++ b/drivers/phy/broadcom/Kconfig
@@ -80,3 +80,13 @@ config PHY_BRCM_USB
This driver is required by the USB XHCI, EHCI and OHCI
drivers.
If unsure, say N.
+
+config PHY_BCM_SR_PCIE
+ tristate "Broadcom Stingray PCIe PHY driver"
+ depends on OF && (ARCH_BCM_IPROC || COMPILE_TEST)
+ select GENERIC_PHY
+ select MFD_SYSCON
+ default ARCH_BCM_IPROC
+ help
+ Enable this to support the Broadcom Stingray PCIe PHY
+ If unsure, say N.
diff --git a/drivers/phy/broadcom/Makefile b/drivers/phy/broadcom/Makefile
index 13e000c..0f60184 100644
--- a/drivers/phy/broadcom/Makefile
+++ b/drivers/phy/broadcom/Makefile
@@ -9,3 +9,5 @@ obj-$(CONFIG_PHY_BRCM_SATA) += phy-brcm-sata.o
obj-$(CONFIG_PHY_BRCM_USB) += phy-brcm-usb-dvr.o

phy-brcm-usb-dvr-objs := phy-brcm-usb.o phy-brcm-usb-init.o
+
+obj-$(CONFIG_PHY_BCM_SR_PCIE) += phy-bcm-sr-pcie.o
diff --git a/drivers/phy/broadcom/phy-bcm-sr-pcie.c b/drivers/phy/broadcom/phy-bcm-sr-pcie.c
new file mode 100644
index 0000000..ff15dae
--- /dev/null
+++ b/drivers/phy/broadcom/phy-bcm-sr-pcie.c
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016-2018 Broadcom
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* we have up to 8 PAXB based RC. The 9th one is always PAXC */
+#define SR_NR_PCIE_PHYS 9
+#define SR_PAXC_PHY_IDX (SR_NR_PCIE_PHYS - 1)
+
+#define PCIE_PIPEMUX_CFG_OFFSET 0x10c
+#define PCIE_PIPEMUX_SELECT_STRAP 0xf
+
+#define CDRU_STRAP_DATA_LSW_OFFSET 0x5c
+#define PCIE_PIPEMUX_SHIFT 19
+#define PCIE_PIPEMUX_MASK 0xf
+
+#define MHB_MEM_PW_PAXC_OFFSET 0x1c0
+#define MHB_PWR_ARR_POWERON 0x8
+#define MHB_PWR_ARR_POWEROK 0x4
+#define MHB_PWR_POWERON 0x2
+#define MHB_PWR_POWEROK 0x1
+#define MHB_PWR_STATUS_MASK (MHB_PWR_ARR_POWERON | \
+ MHB_PWR_ARR_POWEROK | \
+ MHB_PWR_POWERON | \
+ MHB_PWR_POWEROK)
+
+struct sr_pcie_phy_core;
+
+/**
+ * struct sr_pcie_phy - Stingray PCIe PHY
+ *
+ * @core: pointer to the Stingray PCIe PHY core control
+ * @index: PHY index
+ * @phy: pointer to the kernel PHY device
+ */
+struct sr_pcie_phy {
+ struct sr_pcie_phy_core *core;
+ unsigned int index;
+ struct phy *phy;
+};
+
+/**
+ * struct sr_pcie_phy_core - Stingray PCIe PHY core control
+ *
+ * @dev: pointer to device
+ * @base: base register of PCIe SS
+ * @cdru: regmap to the CDRU device
+ * @mhb: regmap to the MHB device
+ * @pipemux: pipemuex strap
+ * @phys: array of PCIe PHYs
+ */
+struct sr_pcie_phy_core {
+ struct device *dev;
+ void __iomem *base;
+ struct regmap *cdru;
+ struct regmap *mhb;
+ u32 pipemux;
+ struct sr_pcie_phy phys[SR_NR_PCIE_PHYS];
+};
+
+/*
+ * PCIe PIPEMUX lookup table
+ *
+ * Each array index represents a PIPEMUX strap setting
+ * The array element represents a bitmap where a set bit means the PCIe
+ * core and associated serdes has been enabled as RC and is available for use
+ */
+static const u8 pipemux_table[] = {
+ /* PIPEMUX = 0, EP 1x16 */
+ 0x00,
+ /* PIPEMUX = 1, EP 2x8 */
+ 0x00,
+ /* PIPEMUX = 2, EP 4x4 */
+ 0x00,
+ /* PIPEMUX = 3, RC 2x8, cores 0, 7 */
+ 0x81,
+ /* PIPEMUX = 4, RC 4x4, cores 0, 1, 6, 7 */
+ 0xc3,
+ /* PIPEMUX = 5, RC 8x2, all 8 cores */
+ 0xff,
+ /* PIPEMUX = 6, RC 3x4 + 2x2, cores 0, 2, 3, 6, 7 */
+ 0xcd,
+ /* PIPEMUX = 7, RC 1x4 + 6x2, cores 0, 2, 3, 4, 5, 6, 7 */
+ 0xfd,
+ /* PIPEMUX = 8, EP 1x8 + RC 4x2, cores 4, 5, 6, 7 */
+ 0xf0,
+ /* PIPEMUX = 9, EP 1x8 + RC 2x4, cores 6, 7 */
+ 0xc0,
+ /* PIPEMUX = 10, EP 2x4 + RC 2x4, cores 1, 6 */
+ 0x42,
+ /* PIPEMUX = 11, EP 2x4 + RC 4x2, cores 2, 3, 4, 5 */
+ 0x3c,
+ /* PIPEMUX = 12, EP 1x4 + RC 6x2, cores 2, 3, 4, 5, 6, 7 */
+ 0xfc,
+ /* PIPEMUX = 13, RC 2x4 + RC 1x4 + 2x2, cores 2, 3, 6 */
+ 0x4c,
+};
+
+/*
+ * Return true if the strap setting is valid
+ */
+static bool pipemux_strap_is_valid(u32 pipemux)
+{
+ return !!(pipemux < ARRAY_SIZE(pipemux_table));
+}
+
+/*
+ * Read the PCIe PIPEMUX from strap
+ */
+static u32 pipemux_strap_read(struct sr_pcie_phy_core *core)
+{
+ u32 pipemux;
+
+ /*
+ * Read PIPEMUX configuration register to determine the pipemux setting
+ *
+ * In the case when the value indicates using HW strap, fall back to
+ * use HW strap
+ */
+ pipemux = readl(core->base + PCIE_PIPEMUX_CFG_OFFSET);
+ pipemux &= PCIE_PIPEMUX_MASK;
+ if (pipemux == PCIE_PIPEMUX_SELECT_STRAP) {
+ regmap_read(core->cdru, CDRU_STRAP_DATA_LSW_OFFSET, &pipemux);
+ pipemux >>= PCIE_PIPEMUX_SHIFT;
+ pipemux &= PCIE_PIPEMUX_MASK;
+ }
+
+ return pipemux;
+}
+
+/*
+ * Given a PIPEMUX strap and PCIe core index, this function returns true if the
+ * PCIe core needs to be enabled
+ */
+static bool pcie_core_is_for_rc(struct sr_pcie_phy *phy)
+{
+ struct sr_pcie_phy_core *core = phy->core;
+ unsigned int core_idx = phy->index;
+
+ return !!((pipemux_table[core->pipemux] >> core_idx) & 0x1);
+}
+
+static int sr_pcie_phy_init(struct phy *p)
+{
+ struct sr_pcie_phy *phy = phy_get_drvdata(p);
+
+ /*
+ * Check whether this PHY is for root complex or not. If yes, return
+ * zero so the host driver can proceed to enumeration. If not, return
+ * an error and that will force the host driver to bail out
+ */
+ if (pcie_core_is_for_rc(phy))
+ return 0;
+ else
+ return -ENODEV;
+}
+
+static int sr_paxc_phy_init(struct phy *p)
+{
+ struct sr_pcie_phy *phy = phy_get_drvdata(p);
+ struct sr_pcie_phy_core *core = phy->core;
+ unsigned int core_idx = phy->index;
+ u32 val;
+
+ if (core_idx != SR_PAXC_PHY_IDX)
+ return -EINVAL;
+
+ regmap_read(core->mhb, MHB_MEM_PW_PAXC_OFFSET, &val);
+ if ((val & MHB_PWR_STATUS_MASK) != MHB_PWR_STATUS_MASK) {
+ dev_err(core->dev, "PAXC is not powered up\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int sr_pcie_phy_exit(struct phy *p)
+{
+ /* dummy function to allow host driver to proceed */
+ return 0;
+}
+
+static int sr_pcie_phy_power_on(struct phy *p)
+{
+ /* dummy function to allow host driver to proceed */
+ return 0;
+}
+
+static int sr_pcie_phy_power_off(struct phy *p)
+{
+ /* dummy function to allow host to proceed */
+ return 0;
+}
+
+static const struct phy_ops sr_pcie_phy_ops = {
+ .init = sr_pcie_phy_init,
+ .exit = sr_pcie_phy_exit,
+ .power_on = sr_pcie_phy_power_on,
+ .power_off = sr_pcie_phy_power_off,
+};
+
+static const struct phy_ops sr_paxc_phy_ops = {
+ .init = sr_paxc_phy_init,
+ .exit = sr_pcie_phy_exit,
+ .power_on = sr_pcie_phy_power_on,
+ .power_off = sr_pcie_phy_power_off,
+};
+
+static struct phy *sr_pcie_phy_xlate(struct device *dev,
+ struct of_phandle_args *args)
+{
+ struct sr_pcie_phy_core *core;
+ int phy_idx;
+
+ core = dev_get_drvdata(dev);
+ if (!core)
+ return ERR_PTR(-EINVAL);
+
+ phy_idx = args->args[0];
+
+ if (WARN_ON(phy_idx >= SR_NR_PCIE_PHYS))
+ return ERR_PTR(-ENODEV);
+
+ return core->phys[phy_idx].phy;
+}
+
+static int sr_pcie_phy_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct sr_pcie_phy_core *core;
+ struct resource *res;
+ struct phy_provider *provider;
+ unsigned int phy_idx = 0;
+
+ core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
+ if (!core)
+ return -ENOMEM;
+
+ core->dev = dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ core->base = devm_ioremap_resource(core->dev, res);
+ if (IS_ERR(core->base))
+ return PTR_ERR(core->base);
+
+ core->cdru = syscon_regmap_lookup_by_phandle(node, "brcm,sr-cdru");
+ if (IS_ERR(core->cdru)) {
+ dev_err(core->dev, "unable to find CDRU device\n");
+ return PTR_ERR(core->cdru);
+ }
+
+ core->mhb = syscon_regmap_lookup_by_phandle(node, "brcm,sr-mhb");
+ if (IS_ERR(core->mhb)) {
+ dev_err(core->dev, "unable to find MHB device\n");
+ return PTR_ERR(core->mhb);
+ }
+
+ /* read the PCIe PIPEMUX strap setting */
+ core->pipemux = pipemux_strap_read(core);
+ if (!pipemux_strap_is_valid(core->pipemux)) {
+ dev_err(core->dev, "invalid PCIe PIPEMUX strap %u\n",
+ core->pipemux);
+ return -EIO;
+ }
+
+ for (phy_idx = 0; phy_idx < SR_NR_PCIE_PHYS; phy_idx++) {
+ struct sr_pcie_phy *p = &core->phys[phy_idx];
+ const struct phy_ops *ops;
+
+ if (phy_idx == SR_PAXC_PHY_IDX)
+ ops = &sr_paxc_phy_ops;
+ else
+ ops = &sr_pcie_phy_ops;
+
+ p->phy = devm_phy_create(dev, NULL, ops);
+ if (IS_ERR(p->phy)) {
+ dev_err(dev, "failed to create PCIe PHY\n");
+ return PTR_ERR(p->phy);
+ }
+
+ p->core = core;
+ p->index = phy_idx;
+ phy_set_drvdata(p->phy, p);
+ }
+
+ dev_set_drvdata(dev, core);
+
+ provider = devm_of_phy_provider_register(dev, sr_pcie_phy_xlate);
+ if (IS_ERR(provider)) {
+ dev_err(dev, "failed to register PHY provider\n");
+ return PTR_ERR(provider);
+ }
+
+ dev_info(dev, "Stingray PCIe PHY driver initialized\n");
+
+ return 0;
+}
+
+static const struct of_device_id sr_pcie_phy_match_table[] = {
+ { .compatible = "brcm,sr-pcie-phy" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sr_pcie_phy_match_table);
+
+static struct platform_driver sr_pcie_phy_driver = {
+ .driver = {
+ .name = "sr-pcie-phy",
+ .of_match_table = sr_pcie_phy_match_table,
+ },
+ .probe = sr_pcie_phy_probe,
+};
+module_platform_driver(sr_pcie_phy_driver);
+
+MODULE_AUTHOR("Ray Jui <ray.jui@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Broadcom Stingray PCIe PHY driver");
+MODULE_LICENSE("GPL v2");
--
2.1.4