[PATCH v12 05/11] PCI: kirin: Add support for bridge slot DT schema

From: Mauro Carvalho Chehab
Date: Tue Sep 28 2021 - 03:34:44 EST


On HiKey970, there's a PEX 8606 PCI bridge on its PHY with
6 lanes. Only 4 lanes are connected:

lane 0 - connected to Kirin 970;
lane 4 - M.2 slot;
lane 5 - mini PCIe slot;
lane 6 - in-board Ethernet controller.

Each lane has its own PERST# gpio pin, and needs a clock
request.

Add support to parse a DT schema containing the above data.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---

To mailbombing on a large number of people, only mailing lists were C/C on the cover.
See [PATCH v12 00/11] at: https://lore.kernel.org/all/cover.1632814194.git.mchehab+huawei@xxxxxxxxxx/

drivers/pci/controller/dwc/pcie-kirin.c | 264 +++++++++++++++++++++---
1 file changed, 232 insertions(+), 32 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
index 0ea92a521e1c..5c97e91adbb0 100644
--- a/drivers/pci/controller/dwc/pcie-kirin.c
+++ b/drivers/pci/controller/dwc/pcie-kirin.c
@@ -52,6 +52,19 @@
#define PCIE_DEBOUNCE_PARAM 0xF0F400
#define PCIE_OE_BYPASS (0x3 << 28)

+/*
+ * Max number of connected PCI slots at an external PCI bridge
+ *
+ * This is used on HiKey 970, which has a PEX 8606 bridge with has
+ * 4 connected lanes (lane 0 upstream, and the other tree lanes,
+ * one connected to an in-board Ethernet adapter and the other two
+ * connected to M.2 and mini PCI slots.
+ *
+ * Each slot has a different clock source and uses a separate PERST#
+ * pin.
+ */
+#define MAX_PCI_SLOTS 3
+
enum pcie_kirin_phy_type {
PCIE_KIRIN_INTERNAL_PHY,
PCIE_KIRIN_EXTERNAL_PHY
@@ -64,6 +77,19 @@ struct kirin_pcie {
struct regmap *apb;
struct phy *phy;
void *phy_priv; /* only for PCIE_KIRIN_INTERNAL_PHY */
+
+ /* DWC PERST# */
+ int gpio_id_dwc_perst;
+
+ /* Per-slot PERST# */
+ int num_slots;
+ int gpio_id_reset[MAX_PCI_SLOTS];
+ const char *reset_names[MAX_PCI_SLOTS];
+
+ /* Per-slot clkreq */
+ int n_gpio_clkreq;
+ int gpio_id_clkreq[MAX_PCI_SLOTS];
+ const char *clkreq_names[MAX_PCI_SLOTS];
};

/*
@@ -87,7 +113,7 @@ struct kirin_pcie {
#define CRGCTRL_PCIE_ASSERT_BIT 0x8c000000

/* Time for delay */
-#define REF_2_PERST_MIN 20000
+#define REF_2_PERST_MIN 21000
#define REF_2_PERST_MAX 25000
#define PERST_2_ACCESS_MIN 10000
#define PERST_2_ACCESS_MAX 12000
@@ -108,7 +134,6 @@ struct hi3660_pcie_phy {
struct clk *phy_ref_clk;
struct clk *aclk;
struct clk *aux_clk;
- int gpio_id_reset;
};

/* Registers in PCIePHY */
@@ -171,16 +196,6 @@ static int hi3660_pcie_phy_get_resource(struct hi3660_pcie_phy *phy)
if (IS_ERR(phy->sysctrl))
return PTR_ERR(phy->sysctrl);

- /* gpios */
- phy->gpio_id_reset = of_get_named_gpio(dev->of_node,
- "reset-gpios", 0);
- if (phy->gpio_id_reset == -EPROBE_DEFER) {
- return -EPROBE_DEFER;
- } else if (!gpio_is_valid(phy->gpio_id_reset)) {
- dev_err(phy->dev, "unable to get a valid gpio pin\n");
- return -ENODEV;
- }
-
return 0;
}

@@ -297,15 +312,7 @@ static int hi3660_pcie_phy_power_on(struct kirin_pcie *pcie)
if (ret)
goto disable_clks;

- /* perst assert Endpoint */
- if (!gpio_request(phy->gpio_id_reset, "pcie_perst")) {
- usleep_range(REF_2_PERST_MIN, REF_2_PERST_MAX);
- ret = gpio_direction_output(phy->gpio_id_reset, 1);
- if (ret)
- goto disable_clks;
- usleep_range(PERST_2_ACCESS_MIN, PERST_2_ACCESS_MAX);
- return 0;
- }
+ return 0;

disable_clks:
hi3660_pcie_phy_clk_ctrl(phy, false);
@@ -347,11 +354,98 @@ static const struct regmap_config pcie_kirin_regmap_conf = {
.reg_stride = 4,
};

+static int kirin_pcie_get_gpio_enable(struct kirin_pcie *pcie,
+ struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ char name[32];
+ int ret, i;
+
+ /* This is an optional property */
+ ret = of_gpio_named_count(np, "hisilicon,clken-gpios");
+ if (ret < 0)
+ return 0;
+
+ if (ret > MAX_PCI_SLOTS) {
+ dev_err(dev, "Too many GPIO clock requests!\n");
+ return -EINVAL;
+ }
+
+ pcie->n_gpio_clkreq = ret;
+
+ for (i = 0; i < pcie->n_gpio_clkreq; i++) {
+ pcie->gpio_id_clkreq[i] = of_get_named_gpio(dev->of_node,
+ "hisilicon,clken-gpios", i);
+ if (pcie->gpio_id_clkreq[i] < 0)
+ return pcie->gpio_id_clkreq[i];
+
+ sprintf(name, "pcie_clkreq_%d", i);
+ pcie->clkreq_names[i] = devm_kstrdup_const(dev, name,
+ GFP_KERNEL);
+ if (!pcie->clkreq_names[i])
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int kirin_pcie_parse_port(struct kirin_pcie *pcie,
+ struct platform_device *pdev,
+ struct device_node *node)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *parent, *child;
+ int ret, slot, i;
+ char name[32];
+
+ for_each_available_child_of_node(node, parent) {
+ for_each_available_child_of_node(parent, child) {
+ i = pcie->num_slots;
+
+ pcie->gpio_id_reset[i] = of_get_named_gpio(child,
+ "reset-gpios", 0);
+ if (pcie->gpio_id_reset[i] < 0)
+ continue;
+
+ pcie->num_slots++;
+ if (pcie->num_slots > MAX_PCI_SLOTS) {
+ dev_err(dev, "Too many PCI slots!\n");
+ return -EINVAL;
+ }
+
+ ret = of_pci_get_devfn(child);
+ if (ret < 0) {
+ dev_err(dev, "failed to parse devfn: %d\n", ret);
+ goto put_node;
+ }
+
+ slot = PCI_SLOT(ret);
+
+ sprintf(name, "pcie_perst_%d", slot);
+ pcie->reset_names[i] = devm_kstrdup_const(dev, name,
+ GFP_KERNEL);
+ if (!pcie->reset_names[i]) {
+ ret = -ENOMEM;
+ goto put_node;
+ }
+ }
+ }
+
+ return 0;
+
+put_node:
+ of_node_put(child);
+ return ret;
+}
+
static long kirin_pcie_get_resource(struct kirin_pcie *kirin_pcie,
struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node, *child;
void __iomem *apb_base;
+ int ret;

apb_base = devm_platform_ioremap_resource_byname(pdev, "apb");
if (IS_ERR(apb_base))
@@ -362,7 +456,32 @@ static long kirin_pcie_get_resource(struct kirin_pcie *kirin_pcie,
if (IS_ERR(kirin_pcie->apb))
return PTR_ERR(kirin_pcie->apb);

+ /* pcie internal PERST# gpio */
+ kirin_pcie->gpio_id_dwc_perst = of_get_named_gpio(dev->of_node,
+ "reset-gpios", 0);
+ if (kirin_pcie->gpio_id_dwc_perst == -EPROBE_DEFER) {
+ return -EPROBE_DEFER;
+ } else if (!gpio_is_valid(kirin_pcie->gpio_id_dwc_perst)) {
+ dev_err(dev, "unable to get a valid gpio pin\n");
+ return -ENODEV;
+ }
+
+ ret = kirin_pcie_get_gpio_enable(kirin_pcie, pdev);
+ if (ret)
+ return ret;
+
+ /* Parse OF children */
+ for_each_available_child_of_node(node, child) {
+ ret = kirin_pcie_parse_port(kirin_pcie, pdev, child);
+ if (ret)
+ goto put_node;
+ }
+
return 0;
+
+put_node:
+ of_node_put(child);
+ return ret;
}

static void kirin_pcie_sideband_dbi_w_mode(struct kirin_pcie *kirin_pcie,
@@ -419,9 +538,33 @@ static int kirin_pcie_wr_own_conf(struct pci_bus *bus, unsigned int devfn,
return PCIBIOS_SUCCESSFUL;
}

+static int kirin_pcie_add_bus(struct pci_bus *bus)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(bus->sysdata);
+ struct kirin_pcie *kirin_pcie = to_kirin_pcie(pci);
+ int i, ret;
+
+ if (!kirin_pcie->num_slots)
+ return 0;
+
+ /* Send PERST# to each slot */
+ for (i = 0; i < kirin_pcie->num_slots; i++) {
+ ret = gpio_direction_output(kirin_pcie->gpio_id_reset[i], 1);
+ if (ret) {
+ dev_err(pci->dev, "PERST# %s error: %d\n",
+ kirin_pcie->reset_names[i], ret);
+ }
+ }
+ usleep_range(PERST_2_ACCESS_MIN, PERST_2_ACCESS_MAX);
+
+ return 0;
+}
+
+
static struct pci_ops kirin_pci_ops = {
.read = kirin_pcie_rd_own_conf,
.write = kirin_pcie_wr_own_conf,
+ .add_bus = kirin_pcie_add_bus,
};

static u32 kirin_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base,
@@ -477,6 +620,44 @@ static int kirin_pcie_host_init(struct pcie_port *pp)
return 0;
}

+static int kirin_pcie_gpio_request(struct kirin_pcie *kirin_pcie,
+ struct device *dev)
+{
+ int ret, i;
+
+ for (i = 0; i < kirin_pcie->num_slots; i++) {
+ if (!gpio_is_valid(kirin_pcie->gpio_id_reset[i])) {
+ dev_err(dev, "unable to get a valid %s gpio\n",
+ kirin_pcie->reset_names[i]);
+ return -ENODEV;
+ }
+
+ ret = devm_gpio_request(dev, kirin_pcie->gpio_id_reset[i],
+ kirin_pcie->reset_names[i]);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < kirin_pcie->n_gpio_clkreq; i++) {
+ if (!gpio_is_valid(kirin_pcie->gpio_id_clkreq[i])) {
+ dev_err(dev, "unable to get a valid %s gpio\n",
+ kirin_pcie->clkreq_names[i]);
+ return -ENODEV;
+ }
+
+ ret = devm_gpio_request(dev, kirin_pcie->gpio_id_clkreq[i],
+ kirin_pcie->clkreq_names[i]);
+ if (ret)
+ return ret;
+
+ ret = gpio_direction_output(kirin_pcie->gpio_id_clkreq[i], 0);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
static const struct dw_pcie_ops kirin_dw_pcie_ops = {
.read_dbi = kirin_pcie_read_dbi,
.write_dbi = kirin_pcie_write_dbi,
@@ -499,24 +680,43 @@ static int kirin_pcie_power_on(struct platform_device *pdev,
if (ret)
return ret;

- return hi3660_pcie_phy_power_on(kirin_pcie);
+ ret = hi3660_pcie_phy_power_on(kirin_pcie);
+ if (ret)
+ return ret;
+ } else {
+ kirin_pcie->phy = devm_of_phy_get(dev, dev->of_node, NULL);
+ if (IS_ERR(kirin_pcie->phy))
+ return PTR_ERR(kirin_pcie->phy);
+
+ ret = kirin_pcie_gpio_request(kirin_pcie, dev);
+ if (ret)
+ return ret;
+
+ ret = phy_init(kirin_pcie->phy);
+ if (ret)
+ goto err;
+
+ ret = phy_power_on(kirin_pcie->phy);
+ if (ret)
+ goto err;
}

- kirin_pcie->phy = devm_of_phy_get(dev, dev->of_node, NULL);
- if (IS_ERR(kirin_pcie->phy))
- return PTR_ERR(kirin_pcie->phy);
+ /* perst assert Endpoint */
+ usleep_range(REF_2_PERST_MIN, REF_2_PERST_MAX);

- ret = phy_init(kirin_pcie->phy);
- if (ret)
- goto err;
+ if (!gpio_request(kirin_pcie->gpio_id_dwc_perst, "pcie_perst_bridge")) {
+ ret = gpio_direction_output(kirin_pcie->gpio_id_dwc_perst, 1);
+ if (ret)
+ goto err;
+ }

- ret = phy_power_on(kirin_pcie->phy);
- if (ret)
- goto err;
+ usleep_range(PERST_2_ACCESS_MIN, PERST_2_ACCESS_MAX);

return 0;
err:
- phy_exit(kirin_pcie->phy);
+ if (kirin_pcie->type != PCIE_KIRIN_INTERNAL_PHY)
+ phy_exit(kirin_pcie->phy);
+
return ret;
}

--
2.31.1