clk: stm32mp1: Split ETHCK_K into separate MUX and GATE clock

The ETHCK_K are modeled as composite clock of MUX and GATE, however per
STM32MP1 Reference Manual RM0436 Rev 3, Page 574, Figure 83. Peripheral
clock distribution for Ethernet, ETHPTPDIV divider is attached past the
ETHCK_K mux, and ETH_CLK/eth_clk_fb clock are output past ETHCKEN gate.
Therefore, in case ETH_CLK/eth_clk_fb are not in use AND PTP clock are
in use, ETHCKEN gate can be turned off. Current driver does not permit
that, fix it.

This patch converts ETHCK_K from composite clock into a ETHCKEN gate,
ETHPTP_K from composite clock into ETHPTPDIV divider, and adds another
NO_ID clock "ck_ker_eth" which models the ETHSRC mux and is parent clock
to both ETHCK_K and ETHPTP_K. Therefore, all references to ETHCK_K and
ETHPTP_K remain functional as before.

[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/20220118202958.1840431-1-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

@@ -2008,7 +2008,6 @@ static const struct clock_config stm32mp1_clock_cfg[] = {
 	KCLK(DSI_K, "dsi_k", dsi_src, 0, G_DSI, M_DSI),
 	KCLK(ADFSDM_K, "adfsdm_k", sai_src, 0, G_ADFSDM, M_SAI1),
 	KCLK(USBO_K, "usbo_k", usbo_src, 0, G_USBO, M_USBO),
-	KCLK(ETHCK_K, "ethck_k", eth_src, 0, G_ETHCK, M_ETHCK),
 
 	/* Particulary Kernel Clocks (no mux or no gate) */
 	MGATE_MP1(DFSDM_K, "dfsdm_k", "ck_mcu", 0, G_DFSDM),
@@ -2017,11 +2016,16 @@ static const struct clock_config stm32mp1_clock_cfg[] = {
 	MGATE_MP1(GPU_K, "gpu_k", "pll2_q", 0, G_GPU),
 	MGATE_MP1(DAC12_K, "dac12_k", "ck_lsi", 0, G_DAC12),
 
-	COMPOSITE(ETHPTP_K, "ethptp_k", eth_src, CLK_OPS_PARENT_ENABLE |
+	COMPOSITE(NO_ID, "ck_ker_eth", eth_src, CLK_OPS_PARENT_ENABLE |
 		  CLK_SET_RATE_NO_REPARENT,
 		  _NO_GATE,
 		  _MMUX(M_ETHCK),
-		  _DIV(RCC_ETHCKSELR, 4, 4, 0, NULL)),
+		  _NO_DIV),
+
+	MGATE_MP1(ETHCK_K, "ethck_k", "ck_ker_eth", 0, G_ETHCK),
+
+	DIV(ETHPTP_K, "ethptp_k", "ck_ker_eth", CLK_OPS_PARENT_ENABLE |
+	    CLK_SET_RATE_NO_REPARENT, RCC_ETHCKSELR, 4, 4, 0),
 
 	/* RTC clock */
 	COMPOSITE(RTC, "ck_rtc", rtc_src, CLK_OPS_PARENT_ENABLE,