Subject: Re: [PATCH 1/5] PCI: qcom: add support for IPQ60xx PCIe controller

From: Rob Herring <[email-masked]>
Date: Tue, 20 Apr 2021 11:18:55 -0500

On Tue, Apr 20, 2021 at 02:21:36PM +0300, Baruch Siach wrote:
> From: Selvam Sathappan Periakaruppan <[email-masked]>
> 
> IPQ60xx series of SoCs have one port of PCIe gen 3. Add support for that
> platform.
> 
> The code is based on downstream Codeaurora kernel v5.4. Split out the
> registers access part from .init into .post_init. Registers are only
> accessible after phy_power_on().
> 
> Signed-off-by: Selvam Sathappan Periakaruppan <[email-masked]>
> Signed-off-by: Baruch Siach <[email-masked]>
> ---
>  drivers/pci/controller/dwc/pcie-qcom.c | 279 +++++++++++++++++++++++++
>  1 file changed, 279 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 8a7a300163e5..3e27de744738 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -41,6 +41,31 @@
>  #define L23_CLK_RMV_DIS				BIT(2)
>  #define L1_CLK_RMV_DIS				BIT(1)
>  
> +#define PCIE_ATU_CR1_OUTBOUND_6_GEN3		0xC00
> +#define PCIE_ATU_CR2_OUTBOUND_6_GEN3		0xC04
> +#define PCIE_ATU_LOWER_BASE_OUTBOUND_6_GEN3	0xC08
> +#define PCIE_ATU_UPPER_BASE_OUTBOUND_6_GEN3	0xC0C
> +#define PCIE_ATU_LIMIT_OUTBOUND_6_GEN3		0xC10
> +#define PCIE_ATU_LOWER_TARGET_OUTBOUND_6_GEN3	0xC14
> +#define PCIE_ATU_UPPER_TARGET_OUTBOUND_6_GEN3	0xC18
> +
> +#define PCIE_ATU_CR1_OUTBOUND_7_GEN3		0xE00
> +#define PCIE_ATU_CR2_OUTBOUND_7_GEN3		0xE04
> +#define PCIE_ATU_LOWER_BASE_OUTBOUND_7_GEN3	0xE08
> +#define PCIE_ATU_UPPER_BASE_OUTBOUND_7_GEN3	0xE0C
> +#define PCIE_ATU_LIMIT_OUTBOUND_7_GEN3		0xE10
> +#define PCIE_ATU_LOWER_TARGET_OUTBOUND_7_GEN3	0xE14
> +#define PCIE_ATU_UPPER_TARGET_OUTBOUND_7_GEN3 	0xE18

ATU registers are standard DWC registers. Plus upstream now dynamically 
detects how many ATU regions there are.

> +
> +#define PCIE20_COMMAND_STATUS			0x04
> +#define BUS_MASTER_EN				0x7
> +#define PCIE20_DEVICE_CONTROL2_STATUS2		0x98
> +#define PCIE_CAP_CPL_TIMEOUT_DISABLE		0x10

All PCI standard registers.

> +#define PCIE30_GEN3_RELATED_OFF			0x890

Looks like a DWC port logic register. The define at a minimum goes in 
the common code. We probably already have one. Code touching the 
register should ideally be there too (hint: look at the other drivers). 

> +
> +#define RXEQ_RGRDLESS_RXTS			BIT(13)
> +#define GEN3_ZRXDC_NONCOMPL			BIT(0)
> +
>  #define PCIE20_PARF_PHY_CTRL			0x40
>  #define PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK	GENMASK(20, 16)
>  #define PHY_CTRL_PHY_TX0_TERM_OFFSET(x)		((x) << 16)
> @@ -52,6 +77,10 @@
>  #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
> @@ -94,6 +123,12 @@
>  #define SLV_ADDR_SPACE_SZ			0x10000000
>  
>  #define PCIE20_LNK_CONTROL2_LINK_STATUS2	0xa0
> +#define PCIE_CAP_CURR_DEEMPHASIS		BIT(16)
> +#define SPEED_GEN1				0x1
> +#define SPEED_GEN2				0x2
> +#define SPEED_GEN3				0x3
> +#define AXI_CLK_RATE				200000000
> +#define RCHNG_CLK_RATE				100000000
>  
>  #define DEVICE_TYPE_RC				0x4
>  
> @@ -168,6 +203,15 @@ struct qcom_pcie_resources_2_7_0 {
>  	struct clk *pipe_clk;
>  };
>  
> +struct qcom_pcie_resources_2_9_0 {
> +	struct clk *iface;
> +	struct clk *axi_m_clk;
> +	struct clk *axi_s_clk;
> +	struct clk *axi_bridge_clk;
> +	struct clk *rchng_clk;
> +	struct reset_control *rst[8];
> +};
> +
>  union qcom_pcie_resources {
>  	struct qcom_pcie_resources_1_0_0 v1_0_0;
>  	struct qcom_pcie_resources_2_1_0 v2_1_0;
> @@ -175,6 +219,7 @@ 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;
> @@ -1266,6 +1311,225 @@ 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 i;
> +	const char *rst_names[] = { "pipe", "sleep", "sticky",
> +				    "axi_m", "axi_s", "ahb",
> +				    "axi_m_sticky", "axi_s_sticky", };
> +
> +	res->iface = devm_clk_get(dev, "iface");
> +	if (IS_ERR(res->iface))
> +		return PTR_ERR(res->iface);
> +
> +	res->axi_m_clk = devm_clk_get(dev, "axi_m");
> +	if (IS_ERR(res->axi_m_clk))
> +		return PTR_ERR(res->axi_m_clk);
> +
> +	res->axi_s_clk = devm_clk_get(dev, "axi_s");
> +	if (IS_ERR(res->axi_s_clk))
> +		return PTR_ERR(res->axi_s_clk);
> +
> +	res->axi_bridge_clk = devm_clk_get(dev, "axi_bridge");
> +	if (IS_ERR(res->axi_bridge_clk))
> +		return PTR_ERR(res->axi_bridge_clk);
> +
> +	res->rchng_clk = devm_clk_get(dev, "rchng");
> +	if (IS_ERR(res->rchng_clk))
> +		return PTR_ERR(res->rchng_clk);
> +
> +	for (i = 0; i < ARRAY_SIZE(rst_names); i++) {
> +		res->rst[i] = devm_reset_control_get(dev, rst_names[i]);

Don't we have a bulk api for this? Clocks too.

> +		if (IS_ERR(res->rst[i])) {
> +			return PTR_ERR(res->rst[i]);
> +		}
> +	}
> +
> +	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_disable_unprepare(res->axi_m_clk);
> +	clk_disable_unprepare(res->axi_s_clk);
> +	clk_disable_unprepare(res->axi_bridge_clk);
> +	clk_disable_unprepare(res->rchng_clk);
> +	clk_disable_unprepare(res->iface);
> +}
> +
> +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 i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(res->rst); i++) {
> +		ret = reset_control_assert(res->rst[i]);
> +		if (ret) {
> +			dev_err(dev, "reset #%d assert failed (%d)\n", i, ret);
> +			return ret;
> +		}
> +	}
> +
> +	usleep_range(2000, 2500);
> +
> +	for (i = 0; i < ARRAY_SIZE(res->rst); i++) {
> +		ret = reset_control_deassert(res->rst[i]);
> +		if (ret) {
> +			dev_err(dev, "reset #%d deassert failed (%d)\n", i,
> +				ret);
> +			return ret;
> +		}
> +	}
> +
> +	/*
> +	 * Don't have a way to see if the reset has completed.
> +	 * Wait for some time.
> +	 */
> +	usleep_range(2000, 2500);
> +
> +	ret = clk_prepare_enable(res->iface);
> +	if (ret) {
> +		dev_err(dev, "cannot prepare/enable core clock\n");
> +		goto err_clk_iface;
> +	}
> +
> +	ret = clk_prepare_enable(res->axi_m_clk);
> +	if (ret) {
> +		dev_err(dev, "cannot prepare/enable core clock\n");
> +		goto err_clk_axi_m;
> +	}
> +
> +	ret = clk_set_rate(res->axi_m_clk, AXI_CLK_RATE);
> +	if (ret) {
> +		dev_err(dev, "MClk rate set failed (%d)\n", ret);
> +		goto err_clk_axi_m;
> +	}
> +
> +	ret = clk_prepare_enable(res->axi_s_clk);
> +	if (ret) {
> +		dev_err(dev, "cannot prepare/enable axi slave clock\n");
> +		goto err_clk_axi_s;
> +	}
> +
> +	ret = clk_set_rate(res->axi_s_clk, AXI_CLK_RATE);
> +	if (ret) {
> +		dev_err(dev, "SClk rate set failed (%d)\n", ret);
> +		goto err_clk_axi_s;
> +	}
> +
> +	ret = clk_prepare_enable(res->axi_bridge_clk);
> +	if (ret) {
> +		dev_err(dev, "cannot prepare/enable axi bridge clock\n");
> +		goto err_clk_axi_bridge;
> +	}
> +
> +	ret = clk_prepare_enable(res->rchng_clk);
> +	if (ret) {
> +		dev_err(dev, "cannot prepare/enable rchng clock\n");
> +		goto err_clk_rchng;
> +	}
> +
> +	ret = clk_set_rate(res->rchng_clk, RCHNG_CLK_RATE);
> +	if (ret) {
> +		dev_err(dev, "rchng_clk rate set failed (%d)\n", ret);
> +		goto err_clk_rchng;
> +	}
> +
> +	return 0;
> +
> +err_clk_rchng:
> +	clk_disable_unprepare(res->rchng_clk);
> +err_clk_axi_bridge:
> +	clk_disable_unprepare(res->axi_bridge_clk);
> +err_clk_axi_s:
> +	clk_disable_unprepare(res->axi_s_clk);
> +err_clk_axi_m:
> +	clk_disable_unprepare(res->axi_m_clk);
> +err_clk_iface:
> +	clk_disable_unprepare(res->iface);
> +	/*
> +	 * Not checking for failure, will anyway return
> +	 * the original failure in 'ret'.
> +	 */
> +	for (i = 0; i < ARRAY_SIZE(res->rst); i++)
> +		reset_control_assert(res->rst[i]);
> +
> +	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);

What's 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(RXEQ_RGRDLESS_RXTS | GEN3_ZRXDC_NONCOMPL,
> +		pci->dbi_base + PCIE30_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);
> +
> +	writel(BUS_MASTER_EN, pci->dbi_base + PCIE20_COMMAND_STATUS);

Pretty sure the DWC core or PCI core does this already.

> +
> +	writel(DBI_RO_WR_EN, pci->dbi_base + PCIE20_MISC_CONTROL_1_REG);
> +	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(PCIE_CAP_CPL_TIMEOUT_DISABLE, pci->dbi_base +
> +		PCIE20_DEVICE_CONTROL2_STATUS2);
> +
> +	writel(PCIE_CAP_CURR_DEEMPHASIS | SPEED_GEN3,
> +			pci->dbi_base + offset + PCI_EXP_DEVCTL2);

This all looks like stuff that should be in the DWC core code. Maybe we 
need an ASPM disable quirk or something? That's probably somewhat 
common.

> +
> +	for (i = 0;i < 256;i++)
> +		writel(0x0, pcie->parf + PCIE20_PARF_BDF_TO_SID_TABLE_N
> +				+ (4 * i));
> +

> +	writel(0x4, pci->atu_base + PCIE_ATU_CR1_OUTBOUND_6_GEN3);
> +	writel(0x90000000, pci->atu_base + PCIE_ATU_CR2_OUTBOUND_6_GEN3);
> +	writel(0x0, pci->atu_base + PCIE_ATU_LOWER_BASE_OUTBOUND_6_GEN3);
> +	writel(0x0, pci->atu_base + PCIE_ATU_UPPER_BASE_OUTBOUND_6_GEN3);
> +	writel(0x00107FFFF, pci->atu_base + PCIE_ATU_LIMIT_OUTBOUND_6_GEN3);
> +	writel(0x0, pci->atu_base + PCIE_ATU_LOWER_TARGET_OUTBOUND_6_GEN3);
> +	writel(0x0, pci->atu_base + PCIE_ATU_UPPER_TARGET_OUTBOUND_6_GEN3);
> +	writel(0x5, pci->atu_base + PCIE_ATU_CR1_OUTBOUND_7_GEN3);
> +	writel(0x90000000, pci->atu_base + PCIE_ATU_CR2_OUTBOUND_7_GEN3);
> +	writel(0x200000, pci->atu_base + PCIE_ATU_LOWER_BASE_OUTBOUND_7_GEN3);
> +	writel(0x0, pci->atu_base + PCIE_ATU_UPPER_BASE_OUTBOUND_7_GEN3);
> +	writel(0x7FFFFF, pci->atu_base + PCIE_ATU_LIMIT_OUTBOUND_7_GEN3);
> +	writel(0x0, pci->atu_base + PCIE_ATU_LOWER_TARGET_OUTBOUND_7_GEN3);
> +	writel(0x0, pci->atu_base + PCIE_ATU_UPPER_TARGET_OUTBOUND_7_GEN3);

This should all be coming from 'ranges' in the DT. If not, why not?

If you haven't caught the theme yet, everything outside of PARF register 
accesses had better have a good explanation why they can't be in common 
code.

> +
> +	return 0;
> +}
> +
>  static int qcom_pcie_link_up(struct dw_pcie *pci)
>  {
>  	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> @@ -1456,6 +1720,15 @@ 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 dw_pcie_ops dw_pcie_ops = {
>  	.link_up = qcom_pcie_link_up,
>  	.start_link = qcom_pcie_start_link,
> @@ -1508,6 +1781,11 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  		goto err_pm_runtime_put;
>  	}
>  
> +	/* We need ATU for .post_init */
> +	pci->atu_base = devm_platform_ioremap_resource_byname(pdev, "atu");

The DWC core handles this now.

> +	if (IS_ERR(pci->atu_base))
> +		pci->atu_base = NULL;
> +
>  	pcie->phy = devm_phy_optional_get(dev, "pciephy");
>  	if (IS_ERR(pcie->phy)) {
>  		ret = PTR_ERR(pcie->phy);
> @@ -1555,6 +1833,7 @@ static const struct of_device_id qcom_pcie_match[] = {
>  	{ .compatible = "qcom,pcie-qcs404", .data = &ops_2_4_0 },
>  	{ .compatible = "qcom,pcie-sdm845", .data = &ops_2_7_0 },
>  	{ .compatible = "qcom,pcie-sm8250", .data = &ops_1_9_0 },
> +	{ .compatible = "qcom,pcie-ipq6018", .data = &ops_2_9_0 },
>  	{ }
>  };
>  
> -- 
> 2.30.2
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> [email-masked]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

_______________________________________________
linux-arm-kernel mailing list
[email-masked]
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel