Re: [PATCH v6 02/10] PCI: imx6: Add ref clock for i.MX95 PCIe
From: Manivannan Sadhasivam <hidden>
Date: 2024-11-15 06:38:27
Also in:
imx, linux-devicetree, linux-pci, lkml
On Fri, Nov 01, 2024 at 03:06:02PM +0800, Richard Zhu wrote:
Add "ref" clock to enable reference clock. To avoid the DT compatibility, i.MX95 REF clock might be optional.
Your wording is not correct. Perhaps you wanted to say, "To avoid breaking DT backwards compatibility"?
quoted hunk ↗ jump to hunk
Replace the devm_clk_bulk_get() by devm_clk_bulk_get_optional() to fetch i.MX95 PCIe optional clocks in driver. If use external clock, ref clock should point to external reference. If use internal clock, CREF_EN in LAST_TO_REG controls reference output, which implement in drivers/clk/imx/clk-imx95-blk-ctl.c. Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> --- drivers/pci/controller/dwc/pci-imx6.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index 808d1f105417..bc8567677a67 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c@@ -82,6 +82,7 @@ enum imx_pcie_variants { #define IMX_PCIE_FLAG_HAS_SERDES BIT(6) #define IMX_PCIE_FLAG_SUPPORT_64BIT BIT(7) #define IMX_PCIE_FLAG_CPU_ADDR_FIXUP BIT(8) +#define IMX_PCIE_FLAG_CUSTOM_PME_TURNOFF BIT(9) #define imx_check_flag(pci, val) (pci->drvdata->flags & val)@@ -98,6 +99,7 @@ struct imx_pcie_drvdata { const char *gpr; const char * const *clk_names; const u32 clks_cnt; + const u32 clks_optional_cnt; const u32 ltssm_off; const u32 ltssm_mask; const u32 mode_off[IMX_PCIE_MAX_INSTANCES];@@ -1278,9 +1280,8 @@ static int imx_pcie_probe(struct platform_device *pdev) struct device_node *np; struct resource *dbi_base; struct device_node *node = dev->of_node; - int ret; + int ret, i, req_cnt; u16 val; - int i; imx_pcie = devm_kzalloc(dev, sizeof(*imx_pcie), GFP_KERNEL); if (!imx_pcie)@@ -1330,7 +1331,10 @@ static int imx_pcie_probe(struct platform_device *pdev) imx_pcie->clks[i].id = imx_pcie->drvdata->clk_names[i]; /* Fetch clocks */ - ret = devm_clk_bulk_get(dev, imx_pcie->drvdata->clks_cnt, imx_pcie->clks); + req_cnt = imx_pcie->drvdata->clks_cnt - imx_pcie->drvdata->clks_optional_cnt; + ret = devm_clk_bulk_get(dev, req_cnt, imx_pcie->clks); + ret |= devm_clk_bulk_get_optional(dev, imx_pcie->drvdata->clks_optional_cnt, + imx_pcie->clks + req_cnt);
Why do you need to use 'clk_bulk' API to get a single reference clock? Just use devm_clk_get_optional(dev, "ref") And who is going to supply the reference clock in the absence of this clockn in DT? - Mani
quoted hunk ↗ jump to hunk
if (ret) return ret;@@ -1480,6 +1484,7 @@ static const char * const imx8mm_clks[] = {"pcie_bus", "pcie", "pcie_aux"}; static const char * const imx8mq_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_aux"}; static const char * const imx6sx_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_inbound_axi"}; static const char * const imx8q_clks[] = {"mstr", "slv", "dbi"}; +static const char * const imx95_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_aux", "ref"}; static const struct imx_pcie_drvdata drvdata[] = { [IMX6Q] = {@@ -1592,9 +1597,11 @@ static const struct imx_pcie_drvdata drvdata[] = { }, [IMX95] = { .variant = IMX95, - .flags = IMX_PCIE_FLAG_HAS_SERDES, - .clk_names = imx8mq_clks, - .clks_cnt = ARRAY_SIZE(imx8mq_clks), + .flags = IMX_PCIE_FLAG_HAS_SERDES | + IMX_PCIE_FLAG_SUPPORTS_SUSPEND, + .clk_names = imx95_clks, + .clks_cnt = ARRAY_SIZE(imx95_clks), + .clks_optional_cnt = 1, .ltssm_off = IMX95_PE0_GEN_CTRL_3, .ltssm_mask = IMX95_PCIE_LTSSM_EN, .mode_off[0] = IMX95_PE0_GEN_CTRL_1,-- 2.37.1
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