msm: mdss: add pll master/slave auto detection for 8996

Set up pll master/slave status base on both pll
GLBL_TEST_CTRL and CLKBUFLR_EN pll registers value.

Change-Id: Ic75e77d5fccb88613ebe435f97a39f5d745fb264
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>

5 files changed, 105 insertions, 25 deletions

diff --git a/drivers/clk/msm/mdss/mdss-dsi-pll-8996-util.c b/drivers/clk/msm/mdss/mdss-dsi-pll-8996-util.c
index 0c954e487065..10aa2bd16928 100644
--- a/drivers/clk/msm/mdss/mdss-dsi-pll-8996-util.c
+++ b/drivers/clk/msm/mdss/mdss-dsi-pll-8996-util.c
@@ -593,6 +593,76 @@ static void pll_db_commit_8996(void __iomem *pll_base,
 	wmb();	/* make sure register committed */
 }
 
+/*
+ * pll_source_finding:
+ * Both GLBL_TEST_CTRL and CLKBUFLR_EN are configured
+ * at mdss_dsi_8996_phy_config()
+ */
+static int pll_source_finding(struct mdss_pll_resources *pll)
+{
+	u32 clk_buf_en;
+	u32 glbl_test_ctrl;
+
+	glbl_test_ctrl = MDSS_PLL_REG_R(pll->pll_base,
+				DSIPHY_CMN_GLBL_TEST_CTRL);
+	clk_buf_en = MDSS_PLL_REG_R(pll->pll_base,
+				DSIPHY_PLL_CLKBUFLR_EN);
+
+	glbl_test_ctrl &= BIT(2);
+	glbl_test_ctrl >>= 2;
+
+	pr_debug("%s: pll=%d clk_buf_en=%x glbl_test_ctrl=%x\n",
+		__func__, pll->index, clk_buf_en, glbl_test_ctrl);
+
+	clk_buf_en &= (PLL_OUTPUT_RIGHT | PLL_OUTPUT_LEFT);
+
+	if ((glbl_test_ctrl == PLL_SOURCE_FROM_LEFT) &&
+			(clk_buf_en == PLL_OUTPUT_BOTH))
+		return PLL_MASTER;
+
+	if ((glbl_test_ctrl == PLL_SOURCE_FROM_RIGHT) &&
+			(clk_buf_en == PLL_OUTPUT_NONE))
+		return PLL_SLAVE;
+
+	if ((glbl_test_ctrl == PLL_SOURCE_FROM_LEFT) &&
+			(clk_buf_en == PLL_OUTPUT_RIGHT))
+		return PLL_STANDALONE;
+
+	pr_debug("%s: Error pll setup, clk_buf_en=%x glbl_test_ctrl=%x\n",
+			__func__, clk_buf_en, glbl_test_ctrl);
+
+	return PLL_UNKNOWN;
+}
+
+static void pll_source_setup(struct mdss_pll_resources *pll)
+{
+	int status;
+	struct dsi_pll_db *pdb = (struct dsi_pll_db *)pll->priv;
+	struct mdss_pll_resources *other;
+
+	if (pdb->source_setup_done)
+		return;
+
+	pdb->source_setup_done++;
+
+	status = pll_source_finding(pll);
+
+	if (status == PLL_STANDALONE || status == PLL_UNKNOWN)
+		return;
+
+	other = pdb->next->pll;
+	if (!other)
+		return;
+
+	pr_debug("%s: status=%d pll=%d other=%d\n", __func__,
+			status, pll->index, other->index);
+
+	if (status == PLL_MASTER)
+		pll->slave = other;
+	else
+		other->slave = pll;
+}
+
 int pll_vco_set_rate_8996(struct clk *c, unsigned long rate)
 {
 	int rc;
@@ -613,8 +683,10 @@ int pll_vco_set_rate_8996(struct clk *c, unsigned long rate)
 		return rc;
 	}
 
-	pr_debug("%s: ndx=%d base=%p rate=%lu\n", __func__,
-				pll->index, pll->pll_base, rate);
+	pll_source_setup(pll);
+
+	pr_debug("%s: ndx=%d base=%p rate=%lu slave=%p\n", __func__,
+				pll->index, pll->pll_base, rate, pll->slave);
 
 	pll->vco_current_rate = rate;
 	pll->vco_ref_clk_rate = vco->ref_clk_rate;
diff --git a/drivers/clk/msm/mdss/mdss-dsi-pll-8996.c b/drivers/clk/msm/mdss/mdss-dsi-pll-8996.c
index 9056ec634ecc..a8faf0813378 100644
--- a/drivers/clk/msm/mdss/mdss-dsi-pll-8996.c
+++ b/drivers/clk/msm/mdss/mdss-dsi-pll-8996.c
@@ -287,8 +287,8 @@ static struct clk_lookup mdss_dsi_pllcc_8996_1[] = {
 int dsi_pll_clock_register_8996(struct platform_device *pdev,
 				struct mdss_pll_resources *pll_res)
 {
-	int rc;
-	static struct mdss_pll_resources *master_pll;
+	int rc, ndx;
+	struct dsi_pll_db *pdb;
 
 	if (!pdev || !pdev->dev.of_node) {
 		pr_err("Invalid input parameters\n");
@@ -300,27 +300,18 @@ int dsi_pll_clock_register_8996(struct platform_device *pdev,
 		return -EPROBE_DEFER;
 	}
 
-	pr_err("ndx=%d is_slave=%d\n", pll_res->index, pll_res->is_slave);
-
 	if (pll_res->index >= DSI_PLL_NUM) {
 		pr_err("pll ndx=%d is NOT supported\n", pll_res->index);
 		return -EINVAL;
 	}
 
-	if (!pll_res->is_slave) {
-		/* master at split display or stand alone */
-		pll_res->priv = &pll_db[pll_res->index];
-		master_pll = pll_res;	/* keep master pll */
-	} else {
-		/* slave pll */
-		if (!master_pll) {
-			pr_err("No match PLL master found for ndx=%d\n",
-							pll_res->index);
-			return -EINVAL;
-		}
-		master_pll->slave = pll_res;
-		return 0;	/* done for slave */
-	}
+	ndx = pll_res->index;
+	pdb = &pll_db[ndx];
+	pll_res->priv = pdb;
+	pdb->pll = pll_res;
+	ndx++;
+	ndx %= DSI_PLL_NUM;
+	pdb->next = &pll_db[ndx];
 
 	/* Set clock source operations */
 
diff --git a/drivers/clk/msm/mdss/mdss-dsi-pll-8996.h b/drivers/clk/msm/mdss/mdss-dsi-pll-8996.h
index 5193eec641bc..94c50acfb771 100644
--- a/drivers/clk/msm/mdss/mdss-dsi-pll-8996.h
+++ b/drivers/clk/msm/mdss/mdss-dsi-pll-8996.h
@@ -146,8 +146,30 @@ enum {
 };
 
 struct dsi_pll_db {
+	struct dsi_pll_db *next;
+	struct mdss_pll_resources *pll;
 	struct dsi_pll_input in;
 	struct dsi_pll_output out;
+	int source_setup_done;
+};
+
+enum {
+	PLL_OUTPUT_NONE,
+	PLL_OUTPUT_RIGHT,
+	PLL_OUTPUT_LEFT,
+	PLL_OUTPUT_BOTH
+};
+
+enum {
+	PLL_SOURCE_FROM_LEFT,
+	PLL_SOURCE_FROM_RIGHT
+};
+
+enum {
+	PLL_UNKNOWN,
+	PLL_STANDALONE,
+	PLL_SLAVE,
+	PLL_MASTER
 };
 
 int pll_vco_set_rate_8996(struct clk *c, unsigned long rate);
diff --git a/drivers/clk/msm/mdss/mdss-pll.c b/drivers/clk/msm/mdss/mdss-pll.c
index 1593ffab14e0..bf118be406cb 100644
--- a/drivers/clk/msm/mdss/mdss-pll.c
+++ b/drivers/clk/msm/mdss/mdss-pll.c
@@ -222,9 +222,6 @@ static int mdss_pll_probe(struct platform_device *pdev)
 		pll_res->index = 0;
 	}
 
-	pll_res->is_slave = of_property_read_bool(pdev->dev.of_node,
-						"qcom,dsi-pll-slave");
-
 	pll_base_reg = platform_get_resource_byname(pdev,
 						IORESOURCE_MEM, "pll_base");
 	if (!pll_base_reg) {
diff --git a/drivers/clk/msm/mdss/mdss-pll.h b/drivers/clk/msm/mdss/mdss-pll.h
index c93cda3784d5..365c21d3f0ca 100644
--- a/drivers/clk/msm/mdss/mdss-pll.h
+++ b/drivers/clk/msm/mdss/mdss-pll.h
@@ -124,8 +124,6 @@ struct mdss_pll_resources {
 	 */
 	uint32_t index;
 
-	bool is_slave;	/* share pll with master */
-
 	struct mdss_pll_resources *slave;
 
 	/*