clk: Add Actions Semi OWL clock support

This commit adds Actions Semi OWL family base clock and S900 SoC
specific clock support. For S900 peripheral clock support, only UART
clock has been added for now.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

5 files changed, 155 insertions, 0 deletions

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index edb4ca5..18bf8a6 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -89,6 +89,7 @@ source "drivers/clk/exynos/Kconfig"
 source "drivers/clk/at91/Kconfig"
 source "drivers/clk/renesas/Kconfig"
 source "drivers/clk/mvebu/Kconfig"
+source "drivers/clk/owl/Kconfig"
 
 config ICS8N3QV01
 	bool "Enable ICS8N3QV01 VCXO driver"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 426c67d..146283c 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_CLK_BCM6345) += clk_bcm6345.o
 obj-$(CONFIG_CLK_BOSTON) += clk_boston.o
 obj-$(CONFIG_CLK_EXYNOS) += exynos/
 obj-$(CONFIG_CLK_HSDK) += clk-hsdk-cgu.o
+obj-$(CONFIG_CLK_OWL) += owl/
 obj-$(CONFIG_CLK_RENESAS) += renesas/
 obj-$(CONFIG_CLK_STM32F) += clk_stm32f.o
 obj-$(CONFIG_CLK_STM32MP1) += clk_stm32mp1.o
diff --git a/drivers/clk/owl/Kconfig b/drivers/clk/owl/Kconfig
new file mode 100644
index 0000000..661f198
--- /dev/null
+++ b/drivers/clk/owl/Kconfig
@@ -0,0 +1,12 @@
+config CLK_OWL
+        bool "Actions Semi OWL clock drivers"
+        depends on CLK && ARCH_OWL
+        help
+          Enable support for clock managemet unit present in Actions Semi
+	  OWL SoCs.
+
+config CLK_S900
+        bool "Actions Semi S900 clock driver"
+        depends on CLK_OWL && ARM64
+        help
+          Enable support for the clocks in Actions Semi S900 SoC.
diff --git a/drivers/clk/owl/Makefile b/drivers/clk/owl/Makefile
new file mode 100644
index 0000000..9132dcc
--- /dev/null
+++ b/drivers/clk/owl/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier:	GPL-2.0+
+
+obj-$(CONFIG_CLK_S900) += clk_s900.o
diff --git a/drivers/clk/owl/clk_s900.c b/drivers/clk/owl/clk_s900.c
new file mode 100644
index 0000000..2b39bb9
--- /dev/null
+++ b/drivers/clk/owl/clk_s900.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Actions Semi S900 clock driver
+ *
+ * Copyright (C) 2015 Actions Semi Co., Ltd.
+ * Copyright (C) 2018 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/arch-owl/clk_s900.h>
+#include <asm/arch-owl/regs_s900.h>
+#include <asm/io.h>
+
+#include <dt-bindings/clock/s900_cmu.h>
+
+void owl_clk_init(struct owl_clk_priv *priv)
+{
+	u32 bus_clk = 0, core_pll, dev_pll;
+
+	/* Enable ASSIST_PLL */
+	setbits_le32(priv->base + CMU_ASSISTPLL, BIT(0));
+
+	udelay(PLL_STABILITY_WAIT_US);
+
+	/* Source HOSC to DEV_CLK */
+	clrbits_le32(priv->base + CMU_DEVPLL, CMU_DEVPLL_CLK);
+
+	/* Configure BUS_CLK */
+	bus_clk |= (CMU_PDBGDIV_DIV | CMU_PERDIV_DIV | CMU_NOCDIV_DIV |
+			CMU_DMMCLK_SRC | CMU_APBCLK_DIV | CMU_AHBCLK_DIV |
+			CMU_NOCCLK_SRC | CMU_CORECLK_HOSC);
+	writel(bus_clk, priv->base + CMU_BUSCLK);
+
+	udelay(PLL_STABILITY_WAIT_US);
+
+	/* Configure CORE_PLL */
+	core_pll = readl(priv->base + CMU_COREPLL);
+	core_pll |= (CMU_COREPLL_EN | CMU_COREPLL_HOSC_EN | CMU_COREPLL_OUT);
+	writel(core_pll, priv->base + CMU_COREPLL);
+
+	udelay(PLL_STABILITY_WAIT_US);
+
+	/* Configure DEV_PLL */
+	dev_pll = readl(priv->base + CMU_DEVPLL);
+	dev_pll |= (CMU_DEVPLL_EN | CMU_DEVPLL_OUT);
+	writel(dev_pll, priv->base + CMU_DEVPLL);
+
+	udelay(PLL_STABILITY_WAIT_US);
+
+	/* Source CORE_PLL for CORE_CLK */
+	clrsetbits_le32(priv->base + CMU_BUSCLK, CMU_CORECLK_MASK,
+			CMU_CORECLK_CPLL);
+
+	/* Source DEV_PLL for DEV_CLK */
+	setbits_le32(priv->base + CMU_DEVPLL, CMU_DEVPLL_CLK);
+
+	udelay(PLL_STABILITY_WAIT_US);
+}
+
+void owl_uart_clk_enable(struct owl_clk_priv *priv)
+{
+	/* Source HOSC for UART5 interface */
+	clrbits_le32(priv->base + CMU_UART5CLK, CMU_UARTCLK_SRC_DEVPLL);
+
+	/* Enable UART5 interface clock */
+	setbits_le32(priv->base + CMU_DEVCLKEN1, CMU_DEVCLKEN1_UART5);
+}
+
+void owl_uart_clk_disable(struct owl_clk_priv *priv)
+{
+	/* Disable UART5 interface clock */
+	clrbits_le32(priv->base + CMU_DEVCLKEN1, CMU_DEVCLKEN1_UART5);
+}
+
+int owl_clk_enable(struct clk *clk)
+{
+	struct owl_clk_priv *priv = dev_get_priv(clk->dev);
+
+	switch (clk->id) {
+	case CLOCK_UART5:
+		owl_uart_clk_enable(priv);
+		break;
+	default:
+		return 0;
+	}
+
+	return 0;
+}
+
+int owl_clk_disable(struct clk *clk)
+{
+	struct owl_clk_priv *priv = dev_get_priv(clk->dev);
+
+	switch (clk->id) {
+	case CLOCK_UART5:
+		owl_uart_clk_disable(priv);
+		break;
+	default:
+		return 0;
+	}
+
+	return 0;
+}
+
+static int owl_clk_probe(struct udevice *dev)
+{
+	struct owl_clk_priv *priv = dev_get_priv(dev);
+
+	priv->base = dev_read_addr(dev);
+	if (priv->base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	/* setup necessary clocks */
+	owl_clk_init(priv);
+
+	return 0;
+}
+
+static struct clk_ops owl_clk_ops = {
+	.enable = owl_clk_enable,
+	.disable = owl_clk_disable,
+};
+
+static const struct udevice_id owl_clk_ids[] = {
+	{ .compatible = "actions,s900-cmu" },
+	{ }
+};
+
+U_BOOT_DRIVER(clk_owl) = {
+	.name		= "clk_s900",
+	.id		= UCLASS_CLK,
+	.of_match	= owl_clk_ids,
+	.ops		= &owl_clk_ops,
+	.priv_auto_alloc_size = sizeof(struct owl_clk_priv),
+	.probe		= owl_clk_probe,
+	.flags		= DM_FLAG_PRE_RELOC,
+};