clk: stm32mp1: Add parent_data to ETHRX clock

Pass parent_data to ETHRX clock with new fw_name = "ETH_RX_CLK/ETH_REF_CLK".
By default, this change has no impact on the operation of the clock driver.
However, due to the fw_name, it permits DT to override ETHRX clock parent,
which might be needed in case the ETHRX clock are supplied by external clock
source.

Example of MCO2 supplying clock to ETH_RX_CLK via external pad-to-pad wire:
&rcc {
         clocks = <&rcc CK_MCO2>;
         clock-names = "ETH_RX_CLK/ETH_REF_CLK";
};

Note that while this patch permits to implement this rare usecase, the issue
with ethernet RX and TX input clock modeling on MP1 is far more complex and
requires more core plumbing.

[1] STM32MP1 Reference Manual RM0436 Rev 3, Page 574,
    Figure 83. Peripheral clock distribution for Ethernet
    https://www.st.com/resource/en/reference_manual/dm00327659-stm32mp157-advanced-armbased-32bit-mpus-stmicroelectronics.pdf

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Christophe Roullier <christophe.roullier@foss.st.com>
Cc: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Link: https://lore.kernel.org/r/20220118202958.1840431-2-marex@denx.de
Tested-by: Johann Neuhauser <jneuhauser@dh-electronics.com>
Acked-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: Marek Vasut

drivers/clk/clk-stm32mp1.c

@@ -155,6 +155,10 @@ static const char * const eth_src[] = {
 	"pll4_p", "pll3_q"
 };
 
+const struct clk_parent_data ethrx_src[] = {
+	{ .name = "ethck_k", .fw_name = "ETH_RX_CLK/ETH_REF_CLK" },
+};
+
 static const char * const rng_src[] = {
 	"ck_csi", "pll4_r", "ck_lse", "ck_lsi"
 };
@@ -317,6 +321,7 @@ struct clock_config {
 	const char *name;
 	const char *parent_name;
 	const char * const *parent_names;
+	const struct clk_parent_data *parent_data;
 	int num_parents;
 	unsigned long flags;
 	void *cfg;
@@ -576,6 +581,7 @@ static struct clk_hw *
 clk_stm32_register_gate_ops(struct device *dev,
 			    const char *name,
 			    const char *parent_name,
+			    const struct clk_parent_data *parent_data,
 			    unsigned long flags,
 			    void __iomem *base,
 			    const struct stm32_gate_cfg *cfg,
@@ -586,7 +592,10 @@ clk_stm32_register_gate_ops(struct device *dev,
 	int ret;
 
 	init.name = name;
-	init.parent_names = &parent_name;
+	if (parent_name)
+		init.parent_names = &parent_name;
+	if (parent_data)
+		init.parent_data = parent_data;
 	init.num_parents = 1;
 	init.flags = flags;
 
@@ -611,6 +620,7 @@ clk_stm32_register_gate_ops(struct device *dev,
 static struct clk_hw *
 clk_stm32_register_composite(struct device *dev,
 			     const char *name, const char * const *parent_names,
+			     const struct clk_parent_data *parent_data,
 			     int num_parents, void __iomem *base,
 			     const struct stm32_composite_cfg *cfg,
 			     unsigned long flags, spinlock_t *lock)
@@ -1135,6 +1145,7 @@ _clk_stm32_register_gate(struct device *dev,
 	return clk_stm32_register_gate_ops(dev,
 				    cfg->name,
 				    cfg->parent_name,
+				    cfg->parent_data,
 				    cfg->flags,
 				    base,
 				    cfg->cfg,
@@ -1148,8 +1159,8 @@ _clk_stm32_register_composite(struct device *dev,
 			      const struct clock_config *cfg)
 {
 	return clk_stm32_register_composite(dev, cfg->name, cfg->parent_names,
-					    cfg->num_parents, base, cfg->cfg,
-					    cfg->flags, lock);
+					    cfg->parent_data, cfg->num_parents,
+					    base, cfg->cfg, cfg->flags, lock);
 }
 
 #define GATE(_id, _name, _parent, _flags, _offset, _bit_idx, _gate_flags)\
@@ -1258,6 +1269,16 @@ _clk_stm32_register_composite(struct device *dev,
 	.func		= _clk_stm32_register_gate,\
 }
 
+#define STM32_GATE_PDATA(_id, _name, _parent, _flags, _gate)\
+{\
+	.id		= _id,\
+	.name		= _name,\
+	.parent_data	= _parent,\
+	.flags		= _flags,\
+	.cfg		= (struct stm32_gate_cfg *) {_gate},\
+	.func		= _clk_stm32_register_gate,\
+}
+
 #define _STM32_GATE(_gate_offset, _gate_bit_idx, _gate_flags, _mgate, _ops)\
 	(&(struct stm32_gate_cfg) {\
 		&(struct gate_cfg) {\
@@ -1291,6 +1312,10 @@ _clk_stm32_register_composite(struct device *dev,
 	STM32_GATE(_id, _name, _parent, _flags,\
 		   _STM32_MGATE(_mgate))
 
+#define MGATE_MP1_PDATA(_id, _name, _parent, _flags, _mgate)\
+	STM32_GATE_PDATA(_id, _name, _parent, _flags,\
+		   _STM32_MGATE(_mgate))
+
 #define _STM32_DIV(_div_offset, _div_shift, _div_width,\
 		   _div_flags, _div_table, _ops)\
 	.div = &(struct stm32_div_cfg) {\
@@ -1354,6 +1379,9 @@ _clk_stm32_register_composite(struct device *dev,
 #define PCLK(_id, _name, _parent, _flags, _mgate)\
 	MGATE_MP1(_id, _name, _parent, _flags, _mgate)
 
+#define PCLK_PDATA(_id, _name, _parent, _flags, _mgate)\
+	MGATE_MP1_PDATA(_id, _name, _parent, _flags, _mgate)
+
 #define KCLK(_id, _name, _parents, _flags, _mgate, _mmux)\
 	     COMPOSITE(_id, _name, _parents, CLK_OPS_PARENT_ENABLE |\
 		       CLK_SET_RATE_NO_REPARENT | _flags,\
@@ -1951,7 +1979,7 @@ static const struct clock_config stm32mp1_clock_cfg[] = {
 	PCLK(MDMA, "mdma", "ck_axi", 0, G_MDMA),
 	PCLK(GPU, "gpu", "ck_axi", 0, G_GPU),
 	PCLK(ETHTX, "ethtx", "ck_axi", 0, G_ETHTX),
-	PCLK(ETHRX, "ethrx", "ck_axi", 0, G_ETHRX),
+	PCLK_PDATA(ETHRX, "ethrx", ethrx_src, 0, G_ETHRX),
 	PCLK(ETHMAC, "ethmac", "ck_axi", 0, G_ETHMAC),
 	PCLK(FMC, "fmc", "ck_axi", CLK_IGNORE_UNUSED, G_FMC),
 	PCLK(QSPI, "qspi", "ck_axi", CLK_IGNORE_UNUSED, G_QSPI),