phy: cadence: Sierra: Add support for skipping configuration

In some cases, a single SerDes instance can be shared between two different
processors, each using a separate link. In these cases, the SerDes
configuration is done in an earlier boot stage. Therefore, add support to
skip reconfiguring, if it is was already configured beforehand.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220128072642.29188-1-a-govindraju@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/cadence/phy-cadence-sierra.c b/drivers/phy/cadence/phy-cadence-sierra.c
index e265647e29a249f0336c047fe58b410885c57b3a..6b917f7bddbed625c9efc29ffba1f823a131e946 100644 (file)
--- a/drivers/phy/cadence/phy-cadence-sierra.c
+++ b/drivers/phy/cadence/phy-cadence-sierra.c
@@ -370,6 +370,7 @@ struct cdns_sierra_phy {
        int nsubnodes;
        u32 num_lanes;
        bool autoconf;
+       int already_configured;
        struct clk_onecell_data clk_data;
        struct clk *output_clks[CDNS_SIERRA_OUTPUT_CLOCKS];
 };
@@ -517,7 +518,7 @@ static int cdns_sierra_phy_init(struct phy *gphy)
        int i, j;
 
        /* Initialise the PHY registers, unless auto configured */
-       if (phy->autoconf || phy->nsubnodes > 1)
+       if (phy->autoconf || phy->already_configured || phy->nsubnodes > 1)
                return 0;
 
        clk_set_rate(phy->input_clks[CMN_REFCLK_DIG_DIV], 25000000);
@@ -646,6 +647,18 @@ static const struct phy_ops ops = {
        .owner          = THIS_MODULE,
 };
 
+static int cdns_sierra_noop_phy_on(struct phy *gphy)
+{
+       usleep_range(5000, 10000);
+
+       return 0;
+}
+
+static const struct phy_ops noop_ops = {
+       .power_on       = cdns_sierra_noop_phy_on,
+       .owner          = THIS_MODULE,
+};
+
 static u8 cdns_sierra_pll_mux_get_parent(struct clk_hw *hw)
 {
        struct cdns_sierra_pll_mux *mux = to_cdns_sierra_pll_mux(hw);
@@ -1118,13 +1131,6 @@ static int cdns_sierra_phy_get_clocks(struct cdns_sierra_phy *sp,
        struct clk *clk;
        int ret;
 
-       clk = devm_clk_get_optional(dev, "phy_clk");
-       if (IS_ERR(clk)) {
-               dev_err(dev, "failed to get clock phy_clk\n");
-               return PTR_ERR(clk);
-       }
-       sp->input_clks[PHY_CLK] = clk;
-
        clk = devm_clk_get_optional(dev, "cmn_refclk_dig_div");
        if (IS_ERR(clk)) {
                dev_err(dev, "cmn_refclk_dig_div clock not found\n");
@@ -1160,17 +1166,33 @@ static int cdns_sierra_phy_get_clocks(struct cdns_sierra_phy *sp,
        return 0;
 }
 
-static int cdns_sierra_phy_enable_clocks(struct cdns_sierra_phy *sp)
+static int cdns_sierra_phy_clk(struct cdns_sierra_phy *sp)
 {
+       struct device *dev = sp->dev;
+       struct clk *clk;
        int ret;
 
+       clk = devm_clk_get_optional(dev, "phy_clk");
+       if (IS_ERR(clk)) {
+               dev_err(dev, "failed to get clock phy_clk\n");
+               return PTR_ERR(clk);
+       }
+       sp->input_clks[PHY_CLK] = clk;
+
        ret = clk_prepare_enable(sp->input_clks[PHY_CLK]);
        if (ret)
                return ret;
 
+       return 0;
+}
+
+static int cdns_sierra_phy_enable_clocks(struct cdns_sierra_phy *sp)
+{
+       int ret;
+
        ret = clk_prepare_enable(sp->output_clks[CDNS_SIERRA_PLL_CMNLC]);
        if (ret)
-               goto err_pll_cmnlc;
+               return ret;
 
        ret = clk_prepare_enable(sp->output_clks[CDNS_SIERRA_PLL_CMNLC1]);
        if (ret)
@@ -1181,9 +1203,6 @@ static int cdns_sierra_phy_enable_clocks(struct cdns_sierra_phy *sp)
 err_pll_cmnlc1:
        clk_disable_unprepare(sp->output_clks[CDNS_SIERRA_PLL_CMNLC]);
 
-err_pll_cmnlc:
-       clk_disable_unprepare(sp->input_clks[PHY_CLK]);
-
        return ret;
 }
 
@@ -1191,7 +1210,8 @@ static void cdns_sierra_phy_disable_clocks(struct cdns_sierra_phy *sp)
 {
        clk_disable_unprepare(sp->output_clks[CDNS_SIERRA_PLL_CMNLC1]);
        clk_disable_unprepare(sp->output_clks[CDNS_SIERRA_PLL_CMNLC]);
-       clk_disable_unprepare(sp->input_clks[PHY_CLK]);
+       if (!sp->already_configured)
+               clk_disable_unprepare(sp->input_clks[PHY_CLK]);
 }
 
 static int cdns_sierra_phy_get_resets(struct cdns_sierra_phy *sp,
@@ -1382,22 +1402,30 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
-       ret = cdns_sierra_phy_get_resets(sp, dev);
-       if (ret)
-               goto unregister_clk;
-
        ret = cdns_sierra_phy_enable_clocks(sp);
        if (ret)
                goto unregister_clk;
 
-       /* Enable APB */
-       reset_control_deassert(sp->apb_rst);
+       regmap_field_read(sp->pma_cmn_ready, &sp->already_configured);
+
+       if (!sp->already_configured) {
+               ret = cdns_sierra_phy_clk(sp);
+               if (ret)
+                       goto clk_disable;
+
+               ret = cdns_sierra_phy_get_resets(sp, dev);
+               if (ret)
+                       goto clk_disable;
+
+               /* Enable APB */
+               reset_control_deassert(sp->apb_rst);
+       }
 
        /* Check that PHY is present */
        regmap_field_read(sp->macro_id_type, &id_value);
        if  (sp->init_data->id_value != id_value) {
                ret = -EINVAL;
-               goto clk_disable;
+               goto ctrl_assert;
        }
 
        sp->autoconf = of_property_read_bool(dn, "cdns,autoconf");
@@ -1433,8 +1461,10 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
 
                sp->num_lanes += sp->phys[node].num_lanes;
 
-               gphy = devm_phy_create(dev, child, &ops);
-
+               if (!sp->already_configured)
+                       gphy = devm_phy_create(dev, child, &ops);
+               else
+                       gphy = devm_phy_create(dev, child, &noop_ops);
                if (IS_ERR(gphy)) {
                        ret = PTR_ERR(gphy);
                        of_node_put(child);
@@ -1455,7 +1485,7 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
        }
 
        /* If more than one subnode, configure the PHY as multilink */
-       if (!sp->autoconf && sp->nsubnodes > 1) {
+       if (!sp->already_configured && !sp->autoconf && sp->nsubnodes > 1) {
                ret = cdns_sierra_phy_configure_multilink(sp);
                if (ret)
                        goto put_control;
@@ -1473,9 +1503,11 @@ static int cdns_sierra_phy_probe(struct platform_device *pdev)
 put_control:
        while (--node >= 0)
                reset_control_put(sp->phys[node].lnk_rst);
+ctrl_assert:
+       if (!sp->already_configured)
+               reset_control_assert(sp->apb_rst);
 clk_disable:
        cdns_sierra_phy_disable_clocks(sp);
-       reset_control_assert(sp->apb_rst);
 unregister_clk:
        cdns_sierra_clk_unregister(sp);
        return ret;