[PATCH v1 2/4] phy: qcom-qmp-pcie: support separate tables for EP mode

[Manivannan Sadhasivam]

On Tue, Jul 26, 2022 at 11:33:59PM +0300, Dmitry Baryshkov wrote:
> The PCIe QMP PHY requires different programming sequences when being
> used for the RC (Root Complex) or for the EP (End Point) modes. Allow
> selecting the submode and thus selecting a set of PHY programming
> tables.
> 

I think you should mention why secondary table is used for differentiating
between RC and EP mode. Something like,

Since the RC and EP modes share common some common init sequence, the common
sequence is kept in the primary table and the different ones were in secondary.

> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 41 ++++++++++++++++--------
>  1 file changed, 28 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index e6272bd3d735..af3577a5d7e4 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -1369,10 +1369,14 @@ struct qmp_phy_cfg {
>  	/* Init sequence for PHY blocks - serdes, tx, rx, pcs */
>  	struct qmp_phy_cfg_tables primary;
>  	/*
> -	 * Init sequence for PHY blocks, providing additional register
> -	 * programming. Unless required it can be left omitted.
> +	 * Init sequences for PHY blocks, providing additional register
> +	 * programming. They are used for providing separate sequences for the
> +	 * Root Complex and for the End Point usecases.
> +	 *
> +	 * If EP mode is not supported, both tables can be left empty.
>  	 */
> -	struct qmp_phy_cfg_tables secondary;
> +	struct qmp_phy_cfg_tables secondary_rc; /* for the RC only */
> +	struct qmp_phy_cfg_tables secondary_ep; /* for the EP only */
>  
>  	/* clock ids to be requested */
>  	const char * const *clk_list;
> @@ -1422,6 +1426,7 @@ struct qmp_phy_cfg {
>   * @index: lane index
>   * @qmp: QMP phy to which this lane belongs
>   * @mode: current PHY mode
> + * @secondary: currently selected PHY secondary init table set
>   */
>  struct qmp_phy {
>  	struct phy *phy;
> @@ -1434,6 +1439,7 @@ struct qmp_phy {
>  	void __iomem *rx2;
>  	void __iomem *pcs_misc;
>  	struct clk *pipe_clk;
> +	const struct qmp_phy_cfg_tables *secondary;
>  	unsigned int index;
>  	struct qcom_qmp *qmp;
>  	enum phy_mode mode;
> @@ -1687,7 +1693,7 @@ static const struct qmp_phy_cfg sm8250_qmp_gen3x1_pciephy_cfg = {
>  	.pcs_misc_tbl		= sm8250_qmp_pcie_pcs_misc_tbl,
>  	.pcs_misc_tbl_num	= ARRAY_SIZE(sm8250_qmp_pcie_pcs_misc_tbl),
>  	},
> -	.secondary = {
> +	.secondary_rc = {
>  	.serdes_tbl		= sm8250_qmp_gen3x1_pcie_serdes_tbl,
>  	.serdes_tbl_num		= ARRAY_SIZE(sm8250_qmp_gen3x1_pcie_serdes_tbl),
>  	.rx_tbl			= sm8250_qmp_gen3x1_pcie_rx_tbl,
> @@ -1730,7 +1736,7 @@ static const struct qmp_phy_cfg sm8250_qmp_gen3x2_pciephy_cfg = {
>  	.pcs_misc_tbl		= sm8250_qmp_pcie_pcs_misc_tbl,
>  	.pcs_misc_tbl_num	= ARRAY_SIZE(sm8250_qmp_pcie_pcs_misc_tbl),
>  	},
> -	.secondary = {
> +	.secondary_rc = {
>  	.tx_tbl			= sm8250_qmp_gen3x2_pcie_tx_tbl,
>  	.tx_tbl_num		= ARRAY_SIZE(sm8250_qmp_gen3x2_pcie_tx_tbl),
>  	.rx_tbl			= sm8250_qmp_gen3x2_pcie_rx_tbl,
> @@ -1955,7 +1961,7 @@ static int qcom_qmp_phy_pcie_serdes_init(struct qmp_phy *qphy)
>  	void __iomem *serdes = qphy->serdes;
>  
>  	qcom_qmp_phy_pcie_configure(serdes, cfg->regs, cfg->primary.serdes_tbl, cfg->primary.serdes_tbl_num);
> -	qcom_qmp_phy_pcie_configure(serdes, cfg->regs, cfg->secondary.serdes_tbl, cfg->secondary.serdes_tbl_num);
> +	qcom_qmp_phy_pcie_configure(serdes, cfg->regs, qphy->secondary->serdes_tbl, qphy->secondary->serdes_tbl_num);
>  
>  	return 0;
>  }
> @@ -2049,6 +2055,10 @@ static int qcom_qmp_phy_pcie_power_on(struct phy *phy)
>  	unsigned int mask, val, ready;
>  	int ret;
>  
> +	/* Default to RC mode if no mode was selected */

While the comment is fine, I think it'd be good if you mention that the mode was
not selected using set_mode() API.

Thanks,
Mani

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