[PATCH v5 0/3] arm64: IPQ6018 PCIe support

[PATCH v5 0/3] arm64: IPQ6018 PCIe support

[Baruch Siach]

This series adds support for the single PCIe lane on IPQ6018 SoCs. The code is 
ported from downstream Codeaurora v5.4 kernel. The main difference from 
downstream code is the split of PCIe registers configuration from .init to 
.post_init, since it requires phy_power_on().

Tested on IPQ6010 based hardware.

Changes in v5:

  * Remove comments from qcom_pcie_init_2_9_0() (Bjorn Andersson)

Changes in v4:

  * Drop applied DT bits

  * Add max-link-speed that was missing from the applied v2 patch

  * Rebase the driver on v5.16-rc3

Changes in v3:

  * Drop applied patches

  * Rely on generic code for speed setup

  * Drop unused macros

  * Formatting fixes

Changes in v2:

  * Add patch moving GEN3_RELATED macros to a common header

  * Drop ATU configuration from pcie-qcom

  * Remove local definition of common registers

  * Use bulk clk and reset APIs

  * Remove msi-parent from device-tree

Baruch Siach (2):
  arm64: dts: qcom: ipq6018: add pcie max-link-speed
  PCI: dwc: tegra: move GEN3_RELATED DBI register to common header

Selvam Sathappan Periakaruppan (1):
  PCI: qcom: add support for IPQ60xx PCIe controller

 arch/arm64/boot/dts/qcom/ipq6018.dtsi        |   1 +
 drivers/pci/controller/dwc/pcie-designware.h |   7 +
 drivers/pci/controller/dwc/pcie-qcom.c       | 137 +++++++++++++++++++
 drivers/pci/controller/dwc/pcie-tegra194.c   |   6 -
 4 files changed, 145 insertions(+), 6 deletions(-)

-- 
2.34.1

[PATCH v5 1/3] arm64: dts: qcom: ipq6018: add pcie max-link-speed

[Baruch Siach]

From: Baruch Siach <baruch.siach@siklu.com>

Add the generic 'max-link-speed' that correctly describes the IPQ6018
PCIe link generation limit. This allows the generic dwc code to
configure the link speed correctly.

Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
---
 arch/arm64/boot/dts/qcom/ipq6018.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/qcom/ipq6018.dtsi b/arch/arm64/boot/dts/qcom/ipq6018.dtsi
index a717fc17523d..665ee301b85d 100644
--- a/arch/arm64/boot/dts/qcom/ipq6018.dtsi
+++ b/arch/arm64/boot/dts/qcom/ipq6018.dtsi
@@ -438,6 +438,7 @@ pcie0: pci@20000000 {
 			linux,pci-domain = <0>;
 			bus-range = <0x00 0xff>;
 			num-lanes = <1>;
+			max-link-speed = <3>;
 			#address-cells = <3>;
 			#size-cells = <2>;
 
-- 
2.34.1

[PATCH v5 2/3] PCI: dwc: tegra: move GEN3_RELATED DBI register to common header

[Baruch Siach]

From: Baruch Siach <baruch.siach@siklu.com>

These are common dwc macros that will be used for other platforms.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
---
 drivers/pci/controller/dwc/pcie-designware.h | 6 ++++++
 drivers/pci/controller/dwc/pcie-tegra194.c   | 6 ------
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 7d6e9b7576be..ea87809ee298 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -74,6 +74,12 @@
 #define PCIE_MSI_INTR0_MASK		0x82C
 #define PCIE_MSI_INTR0_STATUS		0x830
 
+#define GEN3_RELATED_OFF			0x890
+#define GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL	BIT(0)
+#define GEN3_RELATED_OFF_GEN3_EQ_DISABLE	BIT(16)
+#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT	24
+#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK	GENMASK(25, 24)
+
 #define PCIE_PORT_MULTI_LANE_CTRL	0x8C0
 #define PORT_MLTI_UPCFG_SUPPORT		BIT(7)
 
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index b1b5f836a806..74bf66d9afeb 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -193,12 +193,6 @@
 #define GEN3_EQ_CONTROL_OFF_PSET_REQ_VEC_MASK	GENMASK(23, 8)
 #define GEN3_EQ_CONTROL_OFF_FB_MODE_MASK	GENMASK(3, 0)
 
-#define GEN3_RELATED_OFF			0x890
-#define GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL	BIT(0)
-#define GEN3_RELATED_OFF_GEN3_EQ_DISABLE	BIT(16)
-#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT	24
-#define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK	GENMASK(25, 24)
-
 #define PORT_LOGIC_AMBA_ERROR_RESPONSE_DEFAULT	0x8D0
 #define AMBA_ERROR_RESPONSE_CRS_SHIFT		3
 #define AMBA_ERROR_RESPONSE_CRS_MASK		GENMASK(1, 0)
-- 
2.34.1

[PATCH v5 3/3] PCI: qcom: add support for IPQ60xx PCIe controller

[Baruch Siach]

From: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>

IPQ60xx series of SoCs have one port of PCIe gen 3. Add support for that
platform.

The code is based on downstream[1] Codeaurora kernel v5.4 (branch
win.linuxopenwrt.2.0).

Split out the DBI registers access part from .init into .post_init. DBI
registers are only accessible after phy_power_on().

[1] https://source.codeaurora.org/quic/qsdk/oss/kernel/linux-ipq-5.4/

Signed-off-by: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>
Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
---
v5:

  * Remove comments from qcom_pcie_init_2_9_0() (Bjorn Andersson)

v4:

  * Rebase on v5.16-rc1

v3:
  * Drop speed setup; rely on generic code (Rob Herring)

  * Drop unused CLK_RATE macros (Bjorn Helgaas)

  * Minor formatting fixes (Bjorn Helgaas)

  * Add reference to downstream Codeaurora kernel tree (Bjorn Helgaas)

v2:
  * Drop ATU configuration; rely on common code instead

  * Use more common register macros

  * Use bulk clk and reset APIs
---
 drivers/pci/controller/dwc/pcie-designware.h |   1 +
 drivers/pci/controller/dwc/pcie-qcom.c       | 137 +++++++++++++++++++
 2 files changed, 138 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index ea87809ee298..279c3778a13b 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -76,6 +76,7 @@
 
 #define GEN3_RELATED_OFF			0x890
 #define GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL	BIT(0)
+#define GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS	BIT(13)
 #define GEN3_RELATED_OFF_GEN3_EQ_DISABLE	BIT(16)
 #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT	24
 #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK	GENMASK(25, 24)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index c19cd506ed3f..5d47e572da44 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -52,6 +52,10 @@
 #define PCIE20_PARF_DBI_BASE_ADDR		0x168
 #define PCIE20_PARF_SLV_ADDR_SPACE_SIZE		0x16C
 #define PCIE20_PARF_MHI_CLOCK_RESET_CTRL	0x174
+#define AHB_CLK_EN				BIT(0)
+#define MSTR_AXI_CLK_EN				BIT(1)
+#define BYPASS					BIT(4)
+
 #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT	0x178
 #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2	0x1A8
 #define PCIE20_PARF_LTSSM			0x1B0
@@ -171,6 +175,11 @@ struct qcom_pcie_resources_2_7_0 {
 	struct clk *ref_clk_src;
 };
 
+struct qcom_pcie_resources_2_9_0 {
+	struct clk_bulk_data clks[5];
+	struct reset_control *rst;
+};
+
 union qcom_pcie_resources {
 	struct qcom_pcie_resources_1_0_0 v1_0_0;
 	struct qcom_pcie_resources_2_1_0 v2_1_0;
@@ -178,6 +187,7 @@ union qcom_pcie_resources {
 	struct qcom_pcie_resources_2_3_3 v2_3_3;
 	struct qcom_pcie_resources_2_4_0 v2_4_0;
 	struct qcom_pcie_resources_2_7_0 v2_7_0;
+	struct qcom_pcie_resources_2_9_0 v2_9_0;
 };
 
 struct qcom_pcie;
@@ -1297,6 +1307,119 @@ static void qcom_pcie_post_deinit_2_7_0(struct qcom_pcie *pcie)
 	clk_disable_unprepare(res->pipe_clk);
 }
 
+static int qcom_pcie_get_resources_2_9_0(struct qcom_pcie *pcie)
+{
+	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+	struct dw_pcie *pci = pcie->pci;
+	struct device *dev = pci->dev;
+	int ret;
+
+	res->clks[0].id = "iface";
+	res->clks[1].id = "axi_m";
+	res->clks[2].id = "axi_s";
+	res->clks[3].id = "axi_bridge";
+	res->clks[4].id = "rchng";
+
+	ret = devm_clk_bulk_get(dev, ARRAY_SIZE(res->clks), res->clks);
+	if (ret < 0)
+		return ret;
+
+	res->rst = devm_reset_control_array_get_exclusive(dev);
+	if (IS_ERR(res->rst))
+		return PTR_ERR(res->rst);
+
+	return 0;
+}
+
+static void qcom_pcie_deinit_2_9_0(struct qcom_pcie *pcie)
+{
+	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+
+	clk_bulk_disable_unprepare(ARRAY_SIZE(res->clks), res->clks);
+}
+
+static int qcom_pcie_init_2_9_0(struct qcom_pcie *pcie)
+{
+	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
+	struct device *dev = pcie->pci->dev;
+	int ret;
+
+	ret = reset_control_assert(res->rst);
+	if (ret) {
+		dev_err(dev, "reset assert failed (%d)\n", ret);
+		return ret;
+	}
+
+	usleep_range(2000, 2500);
+
+	ret = reset_control_deassert(res->rst);
+	if (ret) {
+		dev_err(dev, "reset deassert failed (%d)\n", ret);
+		return ret;
+	}
+
+	usleep_range(2000, 2500);
+
+	ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
+	if (ret)
+		goto err_reset;
+
+	return 0;
+
+err_reset:
+	reset_control_assert(res->rst);
+
+	return ret;
+}
+
+static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
+{
+	struct dw_pcie *pci = pcie->pci;
+	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u32 val;
+	int i;
+
+	writel(SLV_ADDR_SPACE_SZ,
+		pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE);
+
+	val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
+	val &= ~BIT(0);
+	writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
+
+	writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
+
+	writel(DEVICE_TYPE_RC, pcie->parf + PCIE20_PARF_DEVICE_TYPE);
+	writel(BYPASS | MSTR_AXI_CLK_EN | AHB_CLK_EN,
+		pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
+	writel(GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS
+		| GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL,
+		pci->dbi_base + GEN3_RELATED_OFF);
+
+	writel(MST_WAKEUP_EN | SLV_WAKEUP_EN | MSTR_ACLK_CGC_DIS
+		| SLV_ACLK_CGC_DIS | CORE_CLK_CGC_DIS |
+		AUX_PWR_DET | L23_CLK_RMV_DIS | L1_CLK_RMV_DIS,
+		pcie->parf + PCIE20_PARF_SYS_CTRL);
+
+	writel(0, pcie->parf + PCIE20_PARF_Q2A_FLUSH);
+
+	dw_pcie_dbi_ro_wr_en(pci);
+	writel(PCIE_CAP_LINK1_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP);
+
+	/* Configure PCIe link capabilities for ASPM */
+	val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
+	val &= ~PCI_EXP_LNKCAP_ASPMS;
+	writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);
+
+	writel(PCI_EXP_DEVCTL2_COMP_TMOUT_DIS, pci->dbi_base + offset +
+			PCI_EXP_DEVCTL2);
+
+	for (i = 0; i < 256; i++)
+		writel(0x0, pcie->parf + PCIE20_PARF_BDF_TO_SID_TABLE_N
+				+ (4 * i));
+
+	return 0;
+}
+
 static int qcom_pcie_link_up(struct dw_pcie *pci)
 {
 	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
@@ -1487,6 +1610,15 @@ static const struct qcom_pcie_ops ops_1_9_0 = {
 	.config_sid = qcom_pcie_config_sid_sm8250,
 };
 
+/* Qcom IP rev.: 2.9.0  Synopsys IP rev.: 5.00a */
+static const struct qcom_pcie_ops ops_2_9_0 = {
+	.get_resources = qcom_pcie_get_resources_2_9_0,
+	.init = qcom_pcie_init_2_9_0,
+	.post_init = qcom_pcie_post_init_2_9_0,
+	.deinit = qcom_pcie_deinit_2_9_0,
+	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
+};
+
 static const struct qcom_pcie_cfg apq8084_cfg = {
 	.ops = &ops_1_0_0,
 };
@@ -1520,6 +1652,10 @@ static const struct qcom_pcie_cfg sc7280_cfg = {
 	.pipe_clk_need_muxing = true,
 };
 
+static const struct qcom_pcie_cfg ipq6018_cfg = {
+	.ops = &ops_2_9_0,
+};
+
 static const struct dw_pcie_ops dw_pcie_ops = {
 	.link_up = qcom_pcie_link_up,
 	.start_link = qcom_pcie_start_link,
@@ -1629,6 +1765,7 @@ static const struct of_device_id qcom_pcie_match[] = {
 	{ .compatible = "qcom,pcie-sm8250", .data = &sm8250_cfg },
 	{ .compatible = "qcom,pcie-sc8180x", .data = &sm8250_cfg },
 	{ .compatible = "qcom,pcie-sc7280", .data = &sc7280_cfg },
+	{ .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg },
 	{ }
 };
 
-- 
2.34.1

Re: [PATCH v5 3/3] PCI: qcom: add support for IPQ60xx PCIe controller

[Bjorn Helgaas]

Capitalize subject line to match history, i.e.,

  $ git log --oneline drivers/pci/controller/dwc/pcie-qcom.c
  3f13d611aa6b PCI: qcom: Use __be16 type to store return value from cpu_to_be16()
  4e0e90539bb0 PCI: qcom: Fix an error handling path in 'qcom_pcie_probe()'
  45a3ec891370 PCI: qcom: Add sc8180x compatible
  aa9c0df98c29 PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280
  b89ff410253d PCI: qcom: Replace ops with struct pcie_cfg in pcie match data
  2cfef1971aea PCI: qcom: Use PHY_REFCLK_USE_PAD only for ipq8064
  7081556f81f7 PCI: qcom: Add support for ddrss_sf_tbu clock
  4c9398822106 PCI: qcom: Add support for configuring BDF to SID mapping for SM8250
  e1dd639e374a PCI: qcom: Add SM8250 SoC support

A good one would be:

  PCI: qcom: Add IPQ60xx support

We already know this is a PCIe controller, and it's nice to have the
important words like "IPQ60xx" early in the message so they don't get
truncated or wrapped.

On Mon, Jan 24, 2022 at 06:27:31PM +0200, Baruch Siach wrote:
> From: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>
> 
> IPQ60xx series of SoCs have one port of PCIe gen 3. Add support for that
> platform.
> 
> The code is based on downstream[1] Codeaurora kernel v5.4 (branch
> win.linuxopenwrt.2.0).
> 
> Split out the DBI registers access part from .init into .post_init. DBI
> registers are only accessible after phy_power_on().
> 
> [1] https://source.codeaurora.org/quic/qsdk/oss/kernel/linux-ipq-5.4/
> 
> Signed-off-by: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>
> Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
> ---
> v5:
> 
>   * Remove comments from qcom_pcie_init_2_9_0() (Bjorn Andersson)
> 
> v4:
> 
>   * Rebase on v5.16-rc1
> 
> v3:
>   * Drop speed setup; rely on generic code (Rob Herring)
> 
>   * Drop unused CLK_RATE macros (Bjorn Helgaas)
> 
>   * Minor formatting fixes (Bjorn Helgaas)
> 
>   * Add reference to downstream Codeaurora kernel tree (Bjorn Helgaas)
> 
> v2:
>   * Drop ATU configuration; rely on common code instead
> 
>   * Use more common register macros
> 
>   * Use bulk clk and reset APIs
> ---
>  drivers/pci/controller/dwc/pcie-designware.h |   1 +
>  drivers/pci/controller/dwc/pcie-qcom.c       | 137 +++++++++++++++++++
>  2 files changed, 138 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index ea87809ee298..279c3778a13b 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -76,6 +76,7 @@
>  
>  #define GEN3_RELATED_OFF			0x890
>  #define GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL	BIT(0)
> +#define GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS	BIT(13)
>  #define GEN3_RELATED_OFF_GEN3_EQ_DISABLE	BIT(16)
>  #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT	24
>  #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK	GENMASK(25, 24)
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index c19cd506ed3f..5d47e572da44 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -52,6 +52,10 @@
>  #define PCIE20_PARF_DBI_BASE_ADDR		0x168
>  #define PCIE20_PARF_SLV_ADDR_SPACE_SIZE		0x16C
>  #define PCIE20_PARF_MHI_CLOCK_RESET_CTRL	0x174
> +#define AHB_CLK_EN				BIT(0)
> +#define MSTR_AXI_CLK_EN				BIT(1)
> +#define BYPASS					BIT(4)
> +
>  #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT	0x178
>  #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2	0x1A8
>  #define PCIE20_PARF_LTSSM			0x1B0
> @@ -171,6 +175,11 @@ struct qcom_pcie_resources_2_7_0 {
>  	struct clk *ref_clk_src;
>  };
>  
> +struct qcom_pcie_resources_2_9_0 {
> +	struct clk_bulk_data clks[5];
> +	struct reset_control *rst;
> +};
> +
>  union qcom_pcie_resources {
>  	struct qcom_pcie_resources_1_0_0 v1_0_0;
>  	struct qcom_pcie_resources_2_1_0 v2_1_0;
> @@ -178,6 +187,7 @@ union qcom_pcie_resources {
>  	struct qcom_pcie_resources_2_3_3 v2_3_3;
>  	struct qcom_pcie_resources_2_4_0 v2_4_0;
>  	struct qcom_pcie_resources_2_7_0 v2_7_0;
> +	struct qcom_pcie_resources_2_9_0 v2_9_0;
>  };
>  
>  struct qcom_pcie;
> @@ -1297,6 +1307,119 @@ static void qcom_pcie_post_deinit_2_7_0(struct qcom_pcie *pcie)
>  	clk_disable_unprepare(res->pipe_clk);
>  }
>  
> +static int qcom_pcie_get_resources_2_9_0(struct qcom_pcie *pcie)
> +{
> +	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
> +	struct dw_pcie *pci = pcie->pci;
> +	struct device *dev = pci->dev;
> +	int ret;
> +
> +	res->clks[0].id = "iface";
> +	res->clks[1].id = "axi_m";
> +	res->clks[2].id = "axi_s";
> +	res->clks[3].id = "axi_bridge";
> +	res->clks[4].id = "rchng";
> +
> +	ret = devm_clk_bulk_get(dev, ARRAY_SIZE(res->clks), res->clks);
> +	if (ret < 0)
> +		return ret;
> +
> +	res->rst = devm_reset_control_array_get_exclusive(dev);
> +	if (IS_ERR(res->rst))
> +		return PTR_ERR(res->rst);
> +
> +	return 0;
> +}
> +
> +static void qcom_pcie_deinit_2_9_0(struct qcom_pcie *pcie)
> +{
> +	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
> +
> +	clk_bulk_disable_unprepare(ARRAY_SIZE(res->clks), res->clks);
> +}
> +
> +static int qcom_pcie_init_2_9_0(struct qcom_pcie *pcie)
> +{
> +	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
> +	struct device *dev = pcie->pci->dev;
> +	int ret;
> +
> +	ret = reset_control_assert(res->rst);
> +	if (ret) {
> +		dev_err(dev, "reset assert failed (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(2000, 2500);

Where do these sleep durations come from?  If they're specified
somewhere by PCIe, can you include a citation, e.g., a section number
in the spec.

> +	ret = reset_control_deassert(res->rst);
> +	if (ret) {
> +		dev_err(dev, "reset deassert failed (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(2000, 2500);
> +
> +	ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
> +	if (ret)
> +		goto err_reset;
> +
> +	return 0;
> +
> +err_reset:
> +	reset_control_assert(res->rst);
> +
> +	return ret;
> +}
> +
> +static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
> +{
> +	struct dw_pcie *pci = pcie->pci;
> +	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> +	u32 val;
> +	int i;
> +
> +	writel(SLV_ADDR_SPACE_SZ,
> +		pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE);
> +
> +	val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
> +	val &= ~BIT(0);
> +	writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
> +
> +	writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
> +
> +	writel(DEVICE_TYPE_RC, pcie->parf + PCIE20_PARF_DEVICE_TYPE);
> +	writel(BYPASS | MSTR_AXI_CLK_EN | AHB_CLK_EN,
> +		pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
> +	writel(GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS
> +		| GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL,
> +		pci->dbi_base + GEN3_RELATED_OFF);
> +
> +	writel(MST_WAKEUP_EN | SLV_WAKEUP_EN | MSTR_ACLK_CGC_DIS
> +		| SLV_ACLK_CGC_DIS | CORE_CLK_CGC_DIS |
> +		AUX_PWR_DET | L23_CLK_RMV_DIS | L1_CLK_RMV_DIS,
> +		pcie->parf + PCIE20_PARF_SYS_CTRL);
> +
> +	writel(0, pcie->parf + PCIE20_PARF_Q2A_FLUSH);
> +
> +	dw_pcie_dbi_ro_wr_en(pci);
> +	writel(PCIE_CAP_LINK1_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP);

Is "PCIE_CAP_LINK1_VAL" misnamed?  If it's being written to
PCI_EXP_SLTCAP, seems like it should be named something about a
*slot*, not a *link*.

Or is this an error and it should this be written to PCI_EXP_LNKCAP
instead?

Could PCIE_CAP_LINK1_VAL be defined in terms of PCI_EXP_SLTCAP_* or
PCI_EXP_LNKCAP_*?

> +	/* Configure PCIe link capabilities for ASPM */
> +	val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
> +	val &= ~PCI_EXP_LNKCAP_ASPMS;
> +	writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);

Thanks for using the standard PCI_EXP_LNKCAP and similar #defines.
Does this mean you don't advertise any ASPM support on this platform?
If so, that's fine, but the comment could be more specific.
"Configure" doesn't give any hint about *how* they are configured.

> +	writel(PCI_EXP_DEVCTL2_COMP_TMOUT_DIS, pci->dbi_base + offset +
> +			PCI_EXP_DEVCTL2);
> +
> +	for (i = 0; i < 256; i++)
> +		writel(0x0, pcie->parf + PCIE20_PARF_BDF_TO_SID_TABLE_N
> +				+ (4 * i));
> +
> +	return 0;
> +}
> +
>  static int qcom_pcie_link_up(struct dw_pcie *pci)
>  {
>  	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> @@ -1487,6 +1610,15 @@ static const struct qcom_pcie_ops ops_1_9_0 = {
>  	.config_sid = qcom_pcie_config_sid_sm8250,
>  };
>  
> +/* Qcom IP rev.: 2.9.0  Synopsys IP rev.: 5.00a */
> +static const struct qcom_pcie_ops ops_2_9_0 = {
> +	.get_resources = qcom_pcie_get_resources_2_9_0,
> +	.init = qcom_pcie_init_2_9_0,
> +	.post_init = qcom_pcie_post_init_2_9_0,
> +	.deinit = qcom_pcie_deinit_2_9_0,
> +	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
> +};
> +
>  static const struct qcom_pcie_cfg apq8084_cfg = {
>  	.ops = &ops_1_0_0,
>  };
> @@ -1520,6 +1652,10 @@ static const struct qcom_pcie_cfg sc7280_cfg = {
>  	.pipe_clk_need_muxing = true,
>  };
>  
> +static const struct qcom_pcie_cfg ipq6018_cfg = {
> +	.ops = &ops_2_9_0,
> +};
> +
>  static const struct dw_pcie_ops dw_pcie_ops = {
>  	.link_up = qcom_pcie_link_up,
>  	.start_link = qcom_pcie_start_link,
> @@ -1629,6 +1765,7 @@ static const struct of_device_id qcom_pcie_match[] = {
>  	{ .compatible = "qcom,pcie-sm8250", .data = &sm8250_cfg },
>  	{ .compatible = "qcom,pcie-sc8180x", .data = &sm8250_cfg },
>  	{ .compatible = "qcom,pcie-sc7280", .data = &sc7280_cfg },
> +	{ .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg },
>  	{ }
>  };
>  
> -- 
> 2.34.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v5 3/3] PCI: qcom: add support for IPQ60xx PCIe controller

[Baruch Siach]

Hi Bjorn,

Thanks for your review comments.

On Mon, Jan 24 2022, Bjorn Helgaas wrote:
> Capitalize subject line to match history, i.e.,
>
>   $ git log --oneline drivers/pci/controller/dwc/pcie-qcom.c
>   3f13d611aa6b PCI: qcom: Use __be16 type to store return value from cpu_to_be16()
>   4e0e90539bb0 PCI: qcom: Fix an error handling path in 'qcom_pcie_probe()'
>   45a3ec891370 PCI: qcom: Add sc8180x compatible
>   aa9c0df98c29 PCI: qcom: Switch pcie_1_pipe_clk_src after PHY init in SC7280
>   b89ff410253d PCI: qcom: Replace ops with struct pcie_cfg in pcie match data
>   2cfef1971aea PCI: qcom: Use PHY_REFCLK_USE_PAD only for ipq8064
>   7081556f81f7 PCI: qcom: Add support for ddrss_sf_tbu clock
>   4c9398822106 PCI: qcom: Add support for configuring BDF to SID mapping for SM8250
>   e1dd639e374a PCI: qcom: Add SM8250 SoC support
>
> A good one would be:
>
>   PCI: qcom: Add IPQ60xx support
>
> We already know this is a PCIe controller, and it's nice to have the
> important words like "IPQ60xx" early in the message so they don't get
> truncated or wrapped.
>
> On Mon, Jan 24, 2022 at 06:27:31PM +0200, Baruch Siach wrote:
>> From: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>
>> 
>> IPQ60xx series of SoCs have one port of PCIe gen 3. Add support for that
>> platform.
>> 
>> The code is based on downstream[1] Codeaurora kernel v5.4 (branch
>> win.linuxopenwrt.2.0).
>> 
>> Split out the DBI registers access part from .init into .post_init. DBI
>> registers are only accessible after phy_power_on().
>> 
>> [1] https://source.codeaurora.org/quic/qsdk/oss/kernel/linux-ipq-5.4/
>> 
>> Signed-off-by: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>
>> Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
>> ---
>> v5:
>> 
>>   * Remove comments from qcom_pcie_init_2_9_0() (Bjorn Andersson)
>> 
>> v4:
>> 
>>   * Rebase on v5.16-rc1
>> 
>> v3:
>>   * Drop speed setup; rely on generic code (Rob Herring)
>> 
>>   * Drop unused CLK_RATE macros (Bjorn Helgaas)
>> 
>>   * Minor formatting fixes (Bjorn Helgaas)
>> 
>>   * Add reference to downstream Codeaurora kernel tree (Bjorn Helgaas)
>> 
>> v2:
>>   * Drop ATU configuration; rely on common code instead
>> 
>>   * Use more common register macros
>> 
>>   * Use bulk clk and reset APIs
>> ---
>>  drivers/pci/controller/dwc/pcie-designware.h |   1 +
>>  drivers/pci/controller/dwc/pcie-qcom.c       | 137 +++++++++++++++++++
>>  2 files changed, 138 insertions(+)
>> 
>> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
>> index ea87809ee298..279c3778a13b 100644
>> --- a/drivers/pci/controller/dwc/pcie-designware.h
>> +++ b/drivers/pci/controller/dwc/pcie-designware.h
>> @@ -76,6 +76,7 @@
>>  
>>  #define GEN3_RELATED_OFF			0x890
>>  #define GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL	BIT(0)
>> +#define GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS	BIT(13)
>>  #define GEN3_RELATED_OFF_GEN3_EQ_DISABLE	BIT(16)
>>  #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_SHIFT	24
>>  #define GEN3_RELATED_OFF_RATE_SHADOW_SEL_MASK	GENMASK(25, 24)
>> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
>> index c19cd506ed3f..5d47e572da44 100644
>> --- a/drivers/pci/controller/dwc/pcie-qcom.c
>> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
>> @@ -52,6 +52,10 @@
>>  #define PCIE20_PARF_DBI_BASE_ADDR		0x168
>>  #define PCIE20_PARF_SLV_ADDR_SPACE_SIZE		0x16C
>>  #define PCIE20_PARF_MHI_CLOCK_RESET_CTRL	0x174
>> +#define AHB_CLK_EN				BIT(0)
>> +#define MSTR_AXI_CLK_EN				BIT(1)
>> +#define BYPASS					BIT(4)
>> +
>>  #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT	0x178
>>  #define PCIE20_PARF_AXI_MSTR_WR_ADDR_HALT_V2	0x1A8
>>  #define PCIE20_PARF_LTSSM			0x1B0
>> @@ -171,6 +175,11 @@ struct qcom_pcie_resources_2_7_0 {
>>  	struct clk *ref_clk_src;
>>  };
>>  
>> +struct qcom_pcie_resources_2_9_0 {
>> +	struct clk_bulk_data clks[5];
>> +	struct reset_control *rst;
>> +};
>> +
>>  union qcom_pcie_resources {
>>  	struct qcom_pcie_resources_1_0_0 v1_0_0;
>>  	struct qcom_pcie_resources_2_1_0 v2_1_0;
>> @@ -178,6 +187,7 @@ union qcom_pcie_resources {
>>  	struct qcom_pcie_resources_2_3_3 v2_3_3;
>>  	struct qcom_pcie_resources_2_4_0 v2_4_0;
>>  	struct qcom_pcie_resources_2_7_0 v2_7_0;
>> +	struct qcom_pcie_resources_2_9_0 v2_9_0;
>>  };
>>  
>>  struct qcom_pcie;
>> @@ -1297,6 +1307,119 @@ static void qcom_pcie_post_deinit_2_7_0(struct qcom_pcie *pcie)
>>  	clk_disable_unprepare(res->pipe_clk);
>>  }
>>  
>> +static int qcom_pcie_get_resources_2_9_0(struct qcom_pcie *pcie)
>> +{
>> +	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
>> +	struct dw_pcie *pci = pcie->pci;
>> +	struct device *dev = pci->dev;
>> +	int ret;
>> +
>> +	res->clks[0].id = "iface";
>> +	res->clks[1].id = "axi_m";
>> +	res->clks[2].id = "axi_s";
>> +	res->clks[3].id = "axi_bridge";
>> +	res->clks[4].id = "rchng";
>> +
>> +	ret = devm_clk_bulk_get(dev, ARRAY_SIZE(res->clks), res->clks);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	res->rst = devm_reset_control_array_get_exclusive(dev);
>> +	if (IS_ERR(res->rst))
>> +		return PTR_ERR(res->rst);
>> +
>> +	return 0;
>> +}
>> +
>> +static void qcom_pcie_deinit_2_9_0(struct qcom_pcie *pcie)
>> +{
>> +	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
>> +
>> +	clk_bulk_disable_unprepare(ARRAY_SIZE(res->clks), res->clks);
>> +}
>> +
>> +static int qcom_pcie_init_2_9_0(struct qcom_pcie *pcie)
>> +{
>> +	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
>> +	struct device *dev = pcie->pci->dev;
>> +	int ret;
>> +
>> +	ret = reset_control_assert(res->rst);
>> +	if (ret) {
>> +		dev_err(dev, "reset assert failed (%d)\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	usleep_range(2000, 2500);
>
> Where do these sleep durations come from?  If they're specified
> somewhere by PCIe, can you include a citation, e.g., a section number
> in the spec.

As I mentioned before, I have no access to hardware documentation. I'm
only porting working code from downstream kernel.

In a comment on v4 Bjorn Andersson mentioned "datasheet stating the
minimum timing of the operations to be performed to get the PCIe
controller into a known (clean) state".

  https://lore.kernel.org/all/Ydd5Wh0KeADBQ%2Fh1@ripper/

I have no further details.

>> +	ret = reset_control_deassert(res->rst);
>> +	if (ret) {
>> +		dev_err(dev, "reset deassert failed (%d)\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	usleep_range(2000, 2500);
>> +
>> +	ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
>> +	if (ret)
>> +		goto err_reset;
>> +
>> +	return 0;
>> +
>> +err_reset:
>> +	reset_control_assert(res->rst);
>> +
>> +	return ret;
>> +}
>> +
>> +static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
>> +{
>> +	struct dw_pcie *pci = pcie->pci;
>> +	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>> +	u32 val;
>> +	int i;
>> +
>> +	writel(SLV_ADDR_SPACE_SZ,
>> +		pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE);
>> +
>> +	val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
>> +	val &= ~BIT(0);
>> +	writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
>> +
>> +	writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
>> +
>> +	writel(DEVICE_TYPE_RC, pcie->parf + PCIE20_PARF_DEVICE_TYPE);
>> +	writel(BYPASS | MSTR_AXI_CLK_EN | AHB_CLK_EN,
>> +		pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
>> +	writel(GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS
>> +		| GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL,
>> +		pci->dbi_base + GEN3_RELATED_OFF);
>> +
>> +	writel(MST_WAKEUP_EN | SLV_WAKEUP_EN | MSTR_ACLK_CGC_DIS
>> +		| SLV_ACLK_CGC_DIS | CORE_CLK_CGC_DIS |
>> +		AUX_PWR_DET | L23_CLK_RMV_DIS | L1_CLK_RMV_DIS,
>> +		pcie->parf + PCIE20_PARF_SYS_CTRL);
>> +
>> +	writel(0, pcie->parf + PCIE20_PARF_Q2A_FLUSH);
>> +
>> +	dw_pcie_dbi_ro_wr_en(pci);
>> +	writel(PCIE_CAP_LINK1_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP);
>
> Is "PCIE_CAP_LINK1_VAL" misnamed?  If it's being written to
> PCI_EXP_SLTCAP, seems like it should be named something about a
> *slot*, not a *link*.
>
> Or is this an error and it should this be written to PCI_EXP_LNKCAP
> instead?

As above, I don't know. I can only mention that the exact same
assignment is currently also in qcom_pcie_init_2_3_3().

> Could PCIE_CAP_LINK1_VAL be defined in terms of PCI_EXP_SLTCAP_* or
> PCI_EXP_LNKCAP_*?

It surely can. Whether it makes sense I can't tell.

>> +	/* Configure PCIe link capabilities for ASPM */
>> +	val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
>> +	val &= ~PCI_EXP_LNKCAP_ASPMS;
>> +	writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);
>
> Thanks for using the standard PCI_EXP_LNKCAP and similar #defines.
> Does this mean you don't advertise any ASPM support on this platform?
> If so, that's fine, but the comment could be more specific.
> "Configure" doesn't give any hint about *how* they are configured.

Again, the same code is in qcom_pcie_init_2_3_3(). I'll just drop the
comment in the next submission.

Thanks,
baruch

>> +	writel(PCI_EXP_DEVCTL2_COMP_TMOUT_DIS, pci->dbi_base + offset +
>> +			PCI_EXP_DEVCTL2);
>> +
>> +	for (i = 0; i < 256; i++)
>> +		writel(0x0, pcie->parf + PCIE20_PARF_BDF_TO_SID_TABLE_N
>> +				+ (4 * i));
>> +
>> +	return 0;
>> +}
>> +
>>  static int qcom_pcie_link_up(struct dw_pcie *pci)
>>  {
>>  	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>> @@ -1487,6 +1610,15 @@ static const struct qcom_pcie_ops ops_1_9_0 = {
>>  	.config_sid = qcom_pcie_config_sid_sm8250,
>>  };
>>  
>> +/* Qcom IP rev.: 2.9.0  Synopsys IP rev.: 5.00a */
>> +static const struct qcom_pcie_ops ops_2_9_0 = {
>> +	.get_resources = qcom_pcie_get_resources_2_9_0,
>> +	.init = qcom_pcie_init_2_9_0,
>> +	.post_init = qcom_pcie_post_init_2_9_0,
>> +	.deinit = qcom_pcie_deinit_2_9_0,
>> +	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
>> +};
>> +
>>  static const struct qcom_pcie_cfg apq8084_cfg = {
>>  	.ops = &ops_1_0_0,
>>  };
>> @@ -1520,6 +1652,10 @@ static const struct qcom_pcie_cfg sc7280_cfg = {
>>  	.pipe_clk_need_muxing = true,
>>  };
>>  
>> +static const struct qcom_pcie_cfg ipq6018_cfg = {
>> +	.ops = &ops_2_9_0,
>> +};
>> +
>>  static const struct dw_pcie_ops dw_pcie_ops = {
>>  	.link_up = qcom_pcie_link_up,
>>  	.start_link = qcom_pcie_start_link,
>> @@ -1629,6 +1765,7 @@ static const struct of_device_id qcom_pcie_match[] = {
>>  	{ .compatible = "qcom,pcie-sm8250", .data = &sm8250_cfg },
>>  	{ .compatible = "qcom,pcie-sc8180x", .data = &sm8250_cfg },
>>  	{ .compatible = "qcom,pcie-sc7280", .data = &sc7280_cfg },
>> +	{ .compatible = "qcom,pcie-ipq6018", .data = &ipq6018_cfg },
>>  	{ }
>>  };
>>  
>> -- 
>> 2.34.1

-- 
                                                     ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch@tkos.co.il - tel: +972.52.368.4656, http://www.tkos.co.il -

Re: [PATCH v5 3/3] PCI: qcom: add support for IPQ60xx PCIe controller

[Bjorn Helgaas]

On Tue, Jan 25, 2022 at 09:41:45AM +0200, Baruch Siach wrote:
> On Mon, Jan 24 2022, Bjorn Helgaas wrote:
> > On Mon, Jan 24, 2022 at 06:27:31PM +0200, Baruch Siach wrote:

> >> +static int qcom_pcie_init_2_9_0(struct qcom_pcie *pcie)
> >> +{
> >> +	struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
> >> +	struct device *dev = pcie->pci->dev;
> >> +	int ret;
> >> +
> >> +	ret = reset_control_assert(res->rst);
> >> +	if (ret) {
> >> +		dev_err(dev, "reset assert failed (%d)\n", ret);
> >> +		return ret;
> >> +	}
> >> +
> >> +	usleep_range(2000, 2500);
> >
> > Where do these sleep durations come from?  If they're specified
> > somewhere by PCIe, can you include a citation, e.g., a section number
> > in the spec.
> 
> As I mentioned before, I have no access to hardware documentation. I'm
> only porting working code from downstream kernel.
> 
> In a comment on v4 Bjorn Andersson mentioned "datasheet stating the
> minimum timing of the operations to be performed to get the PCIe
> controller into a known (clean) state".

Sorry if I'm repeating questions.  We can help avoid that by adding a
brief comment here like "black magic copied from working code at X" or
whatever you *do* know.  Repeated questions are wasted effort for both
the author and reviewers.

Sleeps with unsourced durations are always suspect because nobody
wants to wait longer than necessary, and if all we have is a bare
number and nobody knows how it was derived, we can't be confident
about changing it.

>   https://lore.kernel.org/all/Ydd5Wh0KeADBQ%2Fh1@ripper/
> 
> I have no further details.