Hi Manivannan,
> From: Manivannan Sadhasivam, Sent: Saturday, June 8, 2024 5:25 PM
>
> On Mon, May 20, 2024 at 04:42:59PM +0900, Yoshihiro Shimoda wrote:
> > Add support for r8a779g0 (R-Car V4H).
> >
> > This driver previously supported r8a779f0 (R-Car S4-8). PCIe features
> > of both r8a779f0 and r8a779g0 are almost all the same. For example:
> > - PCI Express Base Specification Revision 4.0
> > - Root complex mode and endpoint mode are supported
> > However, r8a779g0 requires specific firmware downloading, to
> > initialize the PHY. Otherwise, the PCIe controller cannot work.
> >
> > The attached firmware file "104_PCIe_fw_addr_data_ver1.05.txt" in
> > the manual is a text file. But, Renesas is not able to distribute
> > the firmware freely. So, we require converting the text file
> > to a binary before the driver runs by using the following script:
> >
> > $ awk '/^\s*0x[0-9A-Fa-f]{4}\s+0x[0-9A-Fa-f]{4}/ \
> > { print substr($2,5,2) substr($2,3,2) }' \
> > 104_PCIe_fw_addr_data_ver1.05.txt | xxd -p -r > \
> > rcar_gen4_pcie.bin
> > $ sha1sum rcar_gen4_pcie.bin
> > 1d0bd4b189b4eb009f5d564b1f93a79112994945 rcar_gen4_pcie.bin
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > ---
> > drivers/pci/controller/dwc/pcie-rcar-gen4.c | 194 +++++++++++++++++++-
> > 1 file changed, 193 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> > index bcbf0a52890d..f766a9739e15 100644
> > --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> > +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c
> > @@ -5,8 +5,10 @@
> > */
> >
> > #include <linux/delay.h>
> > +#include <linux/firmware.h>
> > #include <linux/interrupt.h>
> > #include <linux/io.h>
> > +#include <linux/iopoll.h>
> > #include <linux/module.h>
> > #include <linux/of.h>
> > #include <linux/pci.h>
> > @@ -20,9 +22,10 @@
> > /* Renesas-specific */
> > /* PCIe Mode Setting Register 0 */
> > #define PCIEMSR0 0x0000
> > -#define BIFUR_MOD_SET_ON BIT(0)
> > +#define APP_SRIS_MODE BIT(6)
> > #define DEVICE_TYPE_EP 0
> > #define DEVICE_TYPE_RC BIT(4)
> > +#define BIFUR_MOD_SET_ON BIT(0)
> >
> > /* PCIe Interrupt Status 0 */
> > #define PCIEINTSTS0 0x0084
> > @@ -37,19 +40,36 @@
> > #define PCIEDMAINTSTSEN 0x0314
> > #define PCIEDMAINTSTSEN_INIT GENMASK(15, 0)
> >
> > +/* Port Logic Registers 89 */
> > +#define PRTLGC89 0x0b70
> > +
> > +/* Port Logic Registers 90 */
> > +#define PRTLGC90 0x0b74
> > +
> > /* PCIe Reset Control Register 1 */
> > #define PCIERSTCTRL1 0x0014
> > #define APP_HOLD_PHY_RST BIT(16)
> > #define APP_LTSSM_ENABLE BIT(0)
> >
> > +/* PCIe Power Management Control */
> > +#define PCIEPWRMNGCTRL 0x0070
> > +#define APP_CLK_REQ_N BIT(11)
> > +#define APP_CLK_PM_EN BIT(10)
> > +
> > #define RCAR_NUM_SPEED_CHANGE_RETRIES 10
> > #define RCAR_MAX_LINK_SPEED 4
> >
> > #define RCAR_GEN4_PCIE_EP_FUNC_DBI_OFFSET 0x1000
> > #define RCAR_GEN4_PCIE_EP_FUNC_DBI2_OFFSET 0x800
> >
> > +/* About the firmware, please refer to the commit log */
>
> Which commit log? This is no useful info to the developers. Please add the
> actual information about the firmware here (whatever you mentioned in the commit
> message).
I got it.
> > +#define RCAR_GEN4_PCIE_FIRMWARE_NAME "rcar_gen4_pcie.bin"
> > +#define RCAR_GEN4_PCIE_FIRMWARE_BASE_ADDR 0xc000
> > +MODULE_FIRMWARE(RCAR_GEN4_PCIE_FIRMWARE_NAME);
> > +
> > struct rcar_gen4_pcie;
> > struct rcar_gen4_pcie_drvdata {
> > + void (*additional_common_init)(struct rcar_gen4_pcie *rcar);
> > int (*ltssm_control)(struct rcar_gen4_pcie *rcar, bool enable);
> > enum dw_pcie_device_mode mode;
> > };
> > @@ -57,6 +77,7 @@ struct rcar_gen4_pcie_drvdata {
> > struct rcar_gen4_pcie {
> > struct dw_pcie dw;
> > void __iomem *base;
> > + void __iomem *phy_base;
> > struct platform_device *pdev;
> > const struct rcar_gen4_pcie_drvdata *drvdata;
> > };
> > @@ -180,6 +201,9 @@ static int rcar_gen4_pcie_common_init(struct rcar_gen4_pcie *rcar)
> > if (ret)
> > goto err_unprepare;
> >
> > + if (rcar->drvdata->additional_common_init)
> > + rcar->drvdata->additional_common_init(rcar);
> > +
> > return 0;
> >
> > err_unprepare:
> > @@ -221,6 +245,10 @@ static void rcar_gen4_pcie_unprepare(struct rcar_gen4_pcie *rcar)
> >
> > static int rcar_gen4_pcie_get_resources(struct rcar_gen4_pcie *rcar)
> > {
> > + rcar->phy_base = devm_platform_ioremap_resource_byname(rcar->pdev, "phy");
> > + if (IS_ERR(rcar->phy_base))
> > + return PTR_ERR(rcar->phy_base);
> > +
> > /* Renesas-specific registers */
> > rcar->base = devm_platform_ioremap_resource_byname(rcar->pdev, "app");
> >
> > @@ -514,6 +542,166 @@ static int r8a779f0_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
> > return 0;
> > }
> >
> > +static void rcar_gen4_pcie_additional_common_init(struct rcar_gen4_pcie *rcar)
> > +{
> > + struct dw_pcie *dw = &rcar->dw;
> > + u32 val;
> > +
> > + /*
> > + * The SoC manual said the register setting is required. Otherwise,
> > + * linkup failed.
>
> This also can be dropped.
I got it.
> > + */
> > + val = dw_pcie_readl_dbi(dw, PCIE_PORT_LANE_SKEW);
> > + val &= ~PORT_LANE_SKEW_INSERT_MASK;
> > + if (dw->num_lanes < 4)
> > + val |= BIT(6);
> > + dw_pcie_writel_dbi(dw, PCIE_PORT_LANE_SKEW, val);
> > +
> > + val = readl(rcar->base + PCIEPWRMNGCTRL);
> > + val |= APP_CLK_REQ_N | APP_CLK_PM_EN;
> > + writel(val, rcar->base + PCIEPWRMNGCTRL);
> > +}
> > +
> > +static void rcar_gen4_pcie_phy_reg_update_bits(struct rcar_gen4_pcie *rcar,
> > + u32 offset, u32 mask, u32 val)
> > +{
> > + u32 tmp;
> > +
> > + tmp = readl(rcar->phy_base + offset);
> > + tmp &= ~mask;
> > + tmp |= val;
>
> Use FIELD_* macros to avoid using the shift value.
According to the bitfield.h,
---
* FIELD_{GET,PREP} macros take as first parameter shifted mask
* from which they extract the base mask and shift amount.
* Mask must be a compilation time constant.
---
So, since the mask is a variable here, we cannot use FIELD_* macros for this function.
> > + writel(tmp, rcar->phy_base + offset);
> > +}
> > +
> > +static int rcar_gen4_pcie_reg_test_bit(struct rcar_gen4_pcie *rcar,
> > + u32 offset, u32 mask)
> > +{
> > + struct dw_pcie *dw = &rcar->dw;
> > +
> > + if (dw_pcie_readl_dbi(dw, offset) & mask)
> > + return -EAGAIN;
>
> Here a comment like below could be added at the top of the function
> definition.
>
> /*
> * SoC reference manual suggests checking port logic register bits
> * during firmware write. If read returns non-zero value, then this
> * function returns -EAGAIN indicating that the write needs to be done
> * again. If read returns zero, then return 0 to indicate success.
> */
I got it.
> > +
> > + return 0;
> > +}
> > +
> > +static int rcar_gen4_pcie_download_phy_firmware(struct rcar_gen4_pcie *rcar)
> > +{
> > + /* The check_addr values are magical numbers in the datasheet */
> > + const u32 check_addr[] = { 0x00101018, 0x00101118, 0x00101021, 0x00101121};
> > + struct dw_pcie *dw = &rcar->dw;
> > + const struct firmware *fw;
> > + unsigned int i, timeout;
> > + u32 data;
> > + int ret;
> > +
> > + ret = request_firmware(&fw, RCAR_GEN4_PCIE_FIRMWARE_NAME, dw->dev);
> > + if (ret) {
> > + dev_err(dw->dev, "%s: Requesting firmware failed (%s)\n",
> > + __func__, RCAR_GEN4_PCIE_FIRMWARE_NAME);
>
> dev_err(dw->dev, "Failed to load firmware (%s): %d",
> RCAR_GEN4_PCIE_FIRMWARE_NAME, ret);
>
> > + return ret;
> > + }
> > +
> > + for (i = 0; i < (fw->size / 2); i++) {
> > + data = fw->data[(i * 2) + 1] << 8 | fw->data[i * 2];
> > + timeout = 100;
> > + do {
> > + dw_pcie_writel_dbi(dw, PRTLGC89, RCAR_GEN4_PCIE_FIRMWARE_BASE_ADDR + i);
> > + dw_pcie_writel_dbi(dw, PRTLGC90, data);
> > + if (rcar_gen4_pcie_reg_test_bit(rcar, PRTLGC89, BIT(30)) >= 0)
>
> Can the return value > 0?
No. So, it seems using "!" like below is better, I think.
+ if (!rcar_gen4_pcie_reg_test_bit(rcar, PRTLGC89, BIT(30)))
> > + break;
> > + if (!(--timeout)) {
> > + ret = -ETIMEDOUT;
> > + goto exit;
> > + }
> > + usleep_range(100, 200);
> > + } while (1);
> > + }
> > +
> > + rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x0f8, BIT(17), BIT(17));
> > +
> > + for (i = 0; i < ARRAY_SIZE(check_addr); i++) {
> > + timeout = 100;
> > + do {
> > + dw_pcie_writel_dbi(dw, PRTLGC89, check_addr[i]);
> > + ret = rcar_gen4_pcie_reg_test_bit(rcar, PRTLGC89, BIT(30));
> > + ret |= rcar_gen4_pcie_reg_test_bit(rcar, PRTLGC90, BIT(0));
> > + if (ret >= 0)
>
> Same as above.
I got it.
> > + break;
> > + if (!(--timeout)) {
> > + ret = -ETIMEDOUT;
> > + goto exit;
> > + }
> > + usleep_range(100, 200);
> > + } while (1);
> > + }
> > +
> > + ret = 0;
>
> At this point, ret should be 0, right?
It's right. So, I'll drop this.
> > +exit:
> > + release_firmware(fw);
> > +
> > + return ret;
> > +}
> > +
> > +static int rcar_gen4_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable)
> > +{
> > + struct dw_pcie *dw = &rcar->dw;
> > + u32 val;
> > + int ret;
> > +
> > + if (!enable) {
> > + val = readl(rcar->base + PCIERSTCTRL1);
>
> There is no need to use 'readl/writel' here (which has the barrier), but since
> this driver is already using them, I'm not asking to change it now. But please
> consider switching to _relaxed variants in a separate series.
I got it.
> > + val &= ~APP_LTSSM_ENABLE;
> > + writel(val, rcar->base + PCIERSTCTRL1);
> > +
> > + return 0;
> > + }
> > +
> > + val = dw_pcie_readl_dbi(dw, PCIE_PORT_FORCE);
> > + val |= PORT_FORCE_DO_DESKEW_FOR_SRIS;
> > + dw_pcie_writel_dbi(dw, PCIE_PORT_FORCE, val);
> > +
> > + val = readl(rcar->base + PCIEMSR0);
> > + val |= APP_SRIS_MODE;
> > + writel(val, rcar->base + PCIEMSR0);
> > +
> > + /*
> > + * The R-Car Gen4 documents don't describe the PHY registers' name.
>
> Gen4 datasheet? or reference manual?
I'll write "Gen4 datasheet" instead.
Best regards,
Yoshihiro Shimoda
> - Mani
>
> --
> மணிவண்ணன் சதாசிவம்
