[PATCH v6 01/21] clk: renesas: rzv2h: Add PLLDSI clk mux support

[Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>]

Add PLLDSI clk mux support to select PLLDSI clock from different clock
sources.

Introduce the DEF_PLLDSI_SMUX() macro to define these muxes and register
them in the clock driver.

Extend the determine_rate callback to calculate and propagate PLL
parameters via rzv2h_get_pll_dtable_pars() when LVDS output is selected,
using a new helper function rzv2h_cpg_plldsi_smux_lvds_determine_rate().

The CLK_SMUX2_DSI{0,1}_CLK clock multiplexers select between two paths
with different duty cycles:

- CDIV7_DSIx_CLK (LVDS path, parent index 0): asymmetric H/L=4/3 duty (4/7)
- CSDIV_DSIx (DSI/RGB path, parent index 1): symmetric 50% duty (1/2)

Implement rzv2h_cpg_plldsi_smux_{get,set}_duty_cycle clock operations to
allow the DRM driver to query and configure the appropriate clock path
based on the required output duty cycle.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
---
v5->v6:
 - Fixed rzv2h_cpg_plldsi_smux_clk_register() removed u8 width, mask
   variables and replaced with direct use of smux.width and clk_div_mask(smux.width).

v4->v5:
 - No chages.

v3->v4:
 - Fixed build error using temporary variable mask
   into rzv2h_cpg_plldsi_smux_clk_register().

v2->v3:
 - Added missing defines for duty num/den

v1->v2:
 - Added rzv2h_cpg_plldsi_smux_{get,set}_duty_cycle clock operations to
   allow the DRM driver to query and configure the appropriate clock path
   based on the required output duty cycle.
 - Updated commit message accordingly.

 drivers/clk/renesas/rzv2h-cpg.c | 181 ++++++++++++++++++++++++++++++++
 drivers/clk/renesas/rzv2h-cpg.h |   8 ++
 2 files changed, 189 insertions(+)

diff --git a/drivers/clk/renesas/rzv2h-cpg.c b/drivers/clk/renesas/rzv2h-cpg.c
index f6c47fb89bca..e271c04cee34 100644
--- a/drivers/clk/renesas/rzv2h-cpg.c
+++ b/drivers/clk/renesas/rzv2h-cpg.c
@@ -76,6 +76,11 @@
 /* On RZ/G3E SoC we have two DSI PLLs */
 #define MAX_CPG_DSI_PLL		2
 
+#define CPG_PLLDSI_SMUX_LVDS_DUTY_NUM		4
+#define CPG_PLLDSI_SMUX_LVDS_DUTY_DEN		7
+#define CPG_PLLDSI_SMUX_DSI_RGB_DUTY_NUM	1
+#define CPG_PLLDSI_SMUX_DSI_RGB_DUTY_DEN	2
+
 /**
  * struct rzv2h_pll_dsi_info - PLL DSI information, holds the limits and parameters
  *
@@ -418,6 +423,20 @@ bool rzv2h_get_pll_divs_pars(const struct rzv2h_pll_limits *limits,
 }
 EXPORT_SYMBOL_NS_GPL(rzv2h_get_pll_divs_pars, "RZV2H_CPG");
 
+/**
+ * struct rzv2h_plldsi_mux_clk - PLL DSI MUX clock
+ *
+ * @priv: CPG private data
+ * @mux: mux clk
+ */
+struct rzv2h_plldsi_mux_clk {
+	struct rzv2h_cpg_priv *priv;
+	struct clk_mux mux;
+};
+
+#define to_plldsi_clk_mux(_mux) \
+	container_of(_mux, struct rzv2h_plldsi_mux_clk, mux)
+
 static unsigned long rzv2h_cpg_plldsi_div_recalc_rate(struct clk_hw *hw,
 						      unsigned long parent_rate)
 {
@@ -649,6 +668,165 @@ static int rzv2h_cpg_plldsi_set_rate(struct clk_hw *hw, unsigned long rate,
 	return rzv2h_cpg_pll_set_rate(pll_clk, &dsi_info->pll_dsi_parameters.pll, true);
 }
 
+static u8 rzv2h_cpg_plldsi_smux_get_parent(struct clk_hw *hw)
+{
+	return clk_mux_ops.get_parent(hw);
+}
+
+static int rzv2h_cpg_plldsi_smux_set_parent(struct clk_hw *hw, u8 index)
+{
+	return clk_mux_ops.set_parent(hw, index);
+}
+
+static int rzv2h_cpg_plldsi_smux_lvds_determine_rate(struct rzv2h_cpg_priv *priv,
+						     struct pll_clk *pll_clk,
+						     struct clk_rate_request *req)
+{
+	struct rzv2h_pll_div_pars *dsi_params;
+	struct rzv2h_pll_dsi_info *dsi_info;
+	u8 lvds_table[] = { 7 };
+	u64 rate_millihz;
+
+	dsi_info = &priv->pll_dsi_info[pll_clk->pll.instance];
+	dsi_params = &dsi_info->pll_dsi_parameters;
+
+	rate_millihz = mul_u32_u32(req->rate, MILLI);
+	if (!rzv2h_get_pll_divs_pars(dsi_info->pll_dsi_limits, dsi_params,
+				     lvds_table, ARRAY_SIZE(lvds_table), rate_millihz)) {
+		dev_err(priv->dev, "failed to determine rate for req->rate: %lu\n",
+			req->rate);
+		return -EINVAL;
+	}
+
+	req->rate = DIV_ROUND_CLOSEST_ULL(dsi_params->div.freq_millihz, MILLI);
+	req->best_parent_rate = req->rate;
+	dsi_info->req_pll_dsi_rate = req->best_parent_rate * dsi_params->div.divider_value;
+
+	return 0;
+}
+
+static int rzv2h_cpg_plldsi_smux_determine_rate(struct clk_hw *hw,
+						struct clk_rate_request *req)
+{
+	struct clk_mux *mux = to_clk_mux(hw);
+	struct rzv2h_plldsi_mux_clk *dsi_mux = to_plldsi_clk_mux(mux);
+	struct pll_clk *pll_clk = to_pll(clk_hw_get_parent(hw));
+	struct rzv2h_cpg_priv *priv = dsi_mux->priv;
+
+	/*
+	 * For LVDS output (parent index 0), calculate PLL parameters with
+	 * fixed divider value of 7. For DSI/RGB output (parent index 1) skip
+	 * PLL calculation here as it's handled by determine_rate of the
+	 * divider (up one level).
+	 */
+	if (!clk_mux_ops.get_parent(hw))
+		return rzv2h_cpg_plldsi_smux_lvds_determine_rate(priv, pll_clk, req);
+
+	req->best_parent_rate = req->rate;
+	return 0;
+}
+
+static int rzv2h_cpg_plldsi_smux_get_duty_cycle(struct clk_hw *hw,
+						struct clk_duty *duty)
+{
+	u8 parent = clk_mux_ops.get_parent(hw);
+
+	/*
+	 * CDIV7_DSIx_CLK - LVDS path (div7) - duty 4/7.
+	 * CSDIV_DSIx - DSI/RGB path (csdiv) - duty 1/2.
+	 */
+	if (parent == 0) {
+		duty->num = CPG_PLLDSI_SMUX_LVDS_DUTY_NUM;
+		duty->den = CPG_PLLDSI_SMUX_LVDS_DUTY_DEN;
+	} else {
+		duty->num = CPG_PLLDSI_SMUX_DSI_RGB_DUTY_NUM;
+		duty->den = CPG_PLLDSI_SMUX_DSI_RGB_DUTY_DEN;
+	}
+
+	return 0;
+}
+
+static int rzv2h_cpg_plldsi_smux_set_duty_cycle(struct clk_hw *hw,
+						struct clk_duty *duty)
+{
+	struct clk_hw *parent_hw;
+	u8 parent_idx;
+
+	/*
+	 * Select parent based on requested duty cycle:
+	 * - If duty > 50% (num/den > 1/2), select LVDS path (parent 0)
+	 * - Otherwise, select DSI/RGB path (parent 1)
+	 */
+	if (duty->num * CPG_PLLDSI_SMUX_DSI_RGB_DUTY_DEN >
+	    duty->den * CPG_PLLDSI_SMUX_DSI_RGB_DUTY_NUM)
+		parent_idx = 0;
+	else
+		parent_idx = 1;
+
+	if (parent_idx >= clk_hw_get_num_parents(hw))
+		return -EINVAL;
+
+	parent_hw = clk_hw_get_parent_by_index(hw, parent_idx);
+	if (!parent_hw)
+		return -EINVAL;
+
+	return clk_hw_set_parent(hw, parent_hw);
+}
+
+static const struct clk_ops rzv2h_cpg_plldsi_smux_ops = {
+	.determine_rate = rzv2h_cpg_plldsi_smux_determine_rate,
+	.get_parent = rzv2h_cpg_plldsi_smux_get_parent,
+	.set_parent = rzv2h_cpg_plldsi_smux_set_parent,
+	.get_duty_cycle = rzv2h_cpg_plldsi_smux_get_duty_cycle,
+	.set_duty_cycle = rzv2h_cpg_plldsi_smux_set_duty_cycle,
+};
+
+static struct clk * __init
+rzv2h_cpg_plldsi_smux_clk_register(const struct cpg_core_clk *core,
+				   struct rzv2h_cpg_priv *priv)
+{
+	struct rzv2h_plldsi_mux_clk *clk_hw_data;
+	struct clk_init_data init;
+	struct clk_hw *clk_hw;
+	struct smuxed smux;
+	int ret;
+
+	smux = core->cfg.smux;
+
+	if (smux.shift + smux.width > 16) {
+		dev_err(priv->dev, "mux value exceeds LOWORD field\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	clk_hw_data = devm_kzalloc(priv->dev, sizeof(*clk_hw_data), GFP_KERNEL);
+	if (!clk_hw_data)
+		return ERR_PTR(-ENOMEM);
+
+	clk_hw_data->priv = priv;
+
+	init.name = core->name;
+	init.ops = &rzv2h_cpg_plldsi_smux_ops;
+	init.flags = core->flag;
+	init.parent_names = core->parent_names;
+	init.num_parents = core->num_parents;
+
+	clk_hw_data->mux.reg = priv->base + smux.offset;
+
+	clk_hw_data->mux.shift = smux.shift;
+	clk_hw_data->mux.mask = clk_div_mask(smux.width);
+	clk_hw_data->mux.flags = core->mux_flags;
+	clk_hw_data->mux.lock = &priv->rmw_lock;
+
+	clk_hw = &clk_hw_data->mux.hw;
+	clk_hw->init = &init;
+
+	ret = devm_clk_hw_register(priv->dev, clk_hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return clk_hw->clk;
+}
+
 static int rzv2h_cpg_pll_clk_is_enabled(struct clk_hw *hw)
 {
 	struct pll_clk *pll_clk = to_pll(hw);
@@ -1085,6 +1263,9 @@ rzv2h_cpg_register_core_clk(const struct cpg_core_clk *core,
 	case CLK_TYPE_PLLDSI_DIV:
 		clk = rzv2h_cpg_plldsi_div_clk_register(core, priv);
 		break;
+	case CLK_TYPE_PLLDSI_SMUX:
+		clk = rzv2h_cpg_plldsi_smux_clk_register(core, priv);
+		break;
 	default:
 		goto fail;
 	}
diff --git a/drivers/clk/renesas/rzv2h-cpg.h b/drivers/clk/renesas/rzv2h-cpg.h
index dc957bdaf5e9..74a3824d605e 100644
--- a/drivers/clk/renesas/rzv2h-cpg.h
+++ b/drivers/clk/renesas/rzv2h-cpg.h
@@ -203,6 +203,7 @@ enum clk_types {
 	CLK_TYPE_SMUX,		/* Static Mux */
 	CLK_TYPE_PLLDSI,	/* PLLDSI */
 	CLK_TYPE_PLLDSI_DIV,	/* PLLDSI divider */
+	CLK_TYPE_PLLDSI_SMUX,	/* PLLDSI Static Mux */
 };
 
 #define DEF_TYPE(_name, _id, _type...) \
@@ -241,6 +242,13 @@ enum clk_types {
 		 .dtable = _dtable, \
 		 .parent = _parent, \
 		 .flag = CLK_SET_RATE_PARENT)
+#define DEF_PLLDSI_SMUX(_name, _id, _smux_packed, _parent_names) \
+	DEF_TYPE(_name, _id, CLK_TYPE_PLLDSI_SMUX, \
+		 .cfg.smux = _smux_packed, \
+		 .parent_names = _parent_names, \
+		 .num_parents = ARRAY_SIZE(_parent_names), \
+		 .flag = CLK_SET_RATE_PARENT, \
+		 .mux_flags = CLK_MUX_HIWORD_MASK)
 
 /**
  * struct rzv2h_mod_clk - Module Clocks definitions
-- 
2.43.0