[Patch v5 07/12] clk: lpc32xx: initialize regmap using parent syscon

[Piotr Wojtaszczyk <piotr.wojtaszczyk@xxxxxxxxxxx>]

This allows to share the regmap with other simple-mfd devices like
nxp,lpc32xx-dmamux

Signed-off-by: Piotr Wojtaszczyk <piotr.wojtaszczyk@xxxxxxxxxxx>
---
Changes for v5:
- Add fallback regmap for previous simple-bus DT entry

Changes for v4:
- This patch is new in v4

 drivers/clk/Kconfig           |  1 +
 drivers/clk/nxp/clk-lpc32xx.c | 26 +++++++++++++++-----------
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 3e9099504fad..85ef57d5cccf 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -346,6 +346,7 @@ config COMMON_CLK_LOONGSON2
 config COMMON_CLK_NXP
 	def_bool COMMON_CLK && (ARCH_LPC18XX || ARCH_LPC32XX)
 	select REGMAP_MMIO if ARCH_LPC32XX
+	select MFD_SYSCON if ARCH_LPC32XX
 	select MFD_SYSCON if ARCH_LPC18XX
 	help
 	  Support for clock providers on NXP platforms.
diff --git a/drivers/clk/nxp/clk-lpc32xx.c b/drivers/clk/nxp/clk-lpc32xx.c
index d0f870eff0d6..b8de7f66d1b5 100644
--- a/drivers/clk/nxp/clk-lpc32xx.c
+++ b/drivers/clk/nxp/clk-lpc32xx.c
@@ -7,6 +7,7 @@
 #include <linux/clk-provider.h>
 #include <linux/io.h>
 #include <linux/of_address.h>
+#include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 
 #include <dt-bindings/clock/lpc32xx-clock.h>
@@ -1511,18 +1512,21 @@ static void __init lpc32xx_clk_init(struct device_node *np)
 		return;
 	}
 
-	base = of_iomap(np, 0);
-	if (!base) {
-		pr_err("failed to map system control block registers\n");
-		return;
-	}
-
-	clk_regmap = regmap_init_mmio(NULL, base, &lpc32xx_scb_regmap_config);
+	clk_regmap = syscon_node_to_regmap(np->parent);
 	if (IS_ERR(clk_regmap)) {
-		pr_err("failed to regmap system control block: %ld\n",
-			PTR_ERR(clk_regmap));
-		iounmap(base);
-		return;
+		/* fallback to mmio if syscon fails */
+		base = of_iomap(np, 0);
+		if (!base) {
+			pr_err("failed to map system control block registers\n");
+			return;
+		}
+		clk_regmap = regmap_init_mmio(NULL, base, &lpc32xx_scb_regmap_config);
+		if (IS_ERR(clk_regmap)) {
+			pr_err("failed to regmap system control block: %ld\n",
+			       PTR_ERR(clk_regmap));
+			iounmap(base);
+			return;
+		}
 	}
 
 	/*
-- 
2.25.1