Skip to content

Commit

Permalink
phy: freescale: imx8m-pcie: Refine i.MX8MM PCIe PHY driver
Browse files Browse the repository at this point in the history 
To make it more flexible and easy to expand. Refine i.MX8MM PCIe PHY
driver.
- Use gpr compatible string to avoid the codes duplications when add
  another platform PCIe PHY support.
- Re-arrange the codes to let it more flexible and easy to expand.
No functional change. Re-arrange the TX tuning, since internal registers
can be wrote through APB interface before assertion of CMN_RST.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Marek Vasut <marex@denx.de>
Tested-by: Richard Leitner <richard.leitner@skidata.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.kernel.org/r/1665625622-20551-4-git-send-email-hongxing.zhu@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
  • Loading branch information
Richard Zhu authored and Vinod Koul committed Oct 17, 2022
1 parent e9e7dca commit ca679c4
Showing 1 changed file with 66 additions and 40 deletions.
106 changes: 66 additions & 40 deletions drivers/phy/freescale/phy-fsl-imx8m-pcie.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
Expand Down Expand Up @@ -45,6 +46,15 @@
#define IMX8MM_GPR_PCIE_SSC_EN BIT(16)
#define IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE BIT(9)

enum imx8_pcie_phy_type {
IMX8MM,
};

struct imx8_pcie_phy_drvdata {
const char *gpr;
enum imx8_pcie_phy_type variant;
};

struct imx8_pcie_phy {
void __iomem *base;
struct clk *clk;
Expand All @@ -55,6 +65,7 @@ struct imx8_pcie_phy {
u32 tx_deemph_gen1;
u32 tx_deemph_gen2;
bool clkreq_unused;
const struct imx8_pcie_phy_drvdata *drvdata;
};

static int imx8_pcie_phy_power_on(struct phy *phy)
Expand All @@ -66,31 +77,17 @@ static int imx8_pcie_phy_power_on(struct phy *phy)
reset_control_assert(imx8_phy->reset);

pad_mode = imx8_phy->refclk_pad_mode;
/* Set AUX_EN_OVERRIDE 1'b0, when the CLKREQ# isn't hooked */
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE,
imx8_phy->clkreq_unused ?
0 : IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE);
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_AUX_EN,
IMX8MM_GPR_PCIE_AUX_EN);
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_POWER_OFF, 0);
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_SSC_EN, 0);

regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_REF_CLK_SEL,
pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ?
IMX8MM_GPR_PCIE_REF_CLK_EXT :
IMX8MM_GPR_PCIE_REF_CLK_PLL);
usleep_range(100, 200);

/* Do the PHY common block reset */
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_CMN_RST,
IMX8MM_GPR_PCIE_CMN_RST);
usleep_range(200, 500);
switch (imx8_phy->drvdata->variant) {
case IMX8MM:
/* Tune PHY de-emphasis setting to pass PCIe compliance. */
if (imx8_phy->tx_deemph_gen1)
writel(imx8_phy->tx_deemph_gen1,
imx8_phy->base + PCIE_PHY_TRSV_REG5);
if (imx8_phy->tx_deemph_gen2)
writel(imx8_phy->tx_deemph_gen2,
imx8_phy->base + PCIE_PHY_TRSV_REG6);
break;
}

if (pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ||
pad_mode == IMX8_PCIE_REFCLK_PAD_UNUSED) {
Expand Down Expand Up @@ -118,15 +115,37 @@ static int imx8_pcie_phy_power_on(struct phy *phy)
imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG065);
}

/* Tune PHY de-emphasis setting to pass PCIe compliance. */
if (imx8_phy->tx_deemph_gen1)
writel(imx8_phy->tx_deemph_gen1,
imx8_phy->base + PCIE_PHY_TRSV_REG5);
if (imx8_phy->tx_deemph_gen2)
writel(imx8_phy->tx_deemph_gen2,
imx8_phy->base + PCIE_PHY_TRSV_REG6);
/* Set AUX_EN_OVERRIDE 1'b0, when the CLKREQ# isn't hooked */
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE,
imx8_phy->clkreq_unused ?
0 : IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE);
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_AUX_EN,
IMX8MM_GPR_PCIE_AUX_EN);
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_POWER_OFF, 0);
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_SSC_EN, 0);

reset_control_deassert(imx8_phy->reset);
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_REF_CLK_SEL,
pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ?
IMX8MM_GPR_PCIE_REF_CLK_EXT :
IMX8MM_GPR_PCIE_REF_CLK_PLL);
usleep_range(100, 200);

/* Do the PHY common block reset */
regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14,
IMX8MM_GPR_PCIE_CMN_RST,
IMX8MM_GPR_PCIE_CMN_RST);

switch (imx8_phy->drvdata->variant) {
case IMX8MM:
reset_control_deassert(imx8_phy->reset);
usleep_range(200, 500);
break;
}

/* Polling to check the phy is ready or not. */
ret = readl_poll_timeout(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG075,
Expand Down Expand Up @@ -157,6 +176,17 @@ static const struct phy_ops imx8_pcie_phy_ops = {
.owner = THIS_MODULE,
};

static const struct imx8_pcie_phy_drvdata imx8mm_drvdata = {
.gpr = "fsl,imx8mm-iomuxc-gpr",
.variant = IMX8MM,
};

static const struct of_device_id imx8_pcie_phy_of_match[] = {
{.compatible = "fsl,imx8mm-pcie-phy", .data = &imx8mm_drvdata, },
{ },
};
MODULE_DEVICE_TABLE(of, imx8_pcie_phy_of_match);

static int imx8_pcie_phy_probe(struct platform_device *pdev)
{
struct phy_provider *phy_provider;
Expand All @@ -169,6 +199,8 @@ static int imx8_pcie_phy_probe(struct platform_device *pdev)
if (!imx8_phy)
return -ENOMEM;

imx8_phy->drvdata = of_device_get_match_data(dev);

/* get PHY refclk pad mode */
of_property_read_u32(np, "fsl,refclk-pad-mode",
&imx8_phy->refclk_pad_mode);
Expand All @@ -194,7 +226,7 @@ static int imx8_pcie_phy_probe(struct platform_device *pdev)

/* Grab GPR config register range */
imx8_phy->iomuxc_gpr =
syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
syscon_regmap_lookup_by_compatible(imx8_phy->drvdata->gpr);
if (IS_ERR(imx8_phy->iomuxc_gpr)) {
dev_err(dev, "unable to find iomuxc registers\n");
return PTR_ERR(imx8_phy->iomuxc_gpr);
Expand Down Expand Up @@ -222,12 +254,6 @@ static int imx8_pcie_phy_probe(struct platform_device *pdev)
return PTR_ERR_OR_ZERO(phy_provider);
}

static const struct of_device_id imx8_pcie_phy_of_match[] = {
{.compatible = "fsl,imx8mm-pcie-phy",},
{ },
};
MODULE_DEVICE_TABLE(of, imx8_pcie_phy_of_match);

static struct platform_driver imx8_pcie_phy_driver = {
.probe = imx8_pcie_phy_probe,
.driver = {
Expand Down

0 comments on commit ca679c4

Please sign in to comment.