imx: mx7ulp: Add clock framework and functions

Add a clock framework to support SCG1/PCC2/PCC3 for A7 to support get/set
clock source, divider, clock rate and parent source.
Users need to include pcc.h to use the APIs to for peripherals clock. Each
peripheral clock is defined in enum pcc_clk type.

SCG relevants APIs are defined in scg.h which supports clock rate get, PLL/PFD
enablement and settings, and all SCG clock initialization. User need use enum
scg_clk to access each clock source.

In clock.c, we initialize necessary clocks at u-boot s_init and implement the
clock functions used by driver modules to operate clocks dynamically.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Ye Li <ye.li@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/cpu/armv7/mx7ulp/clock.c b/arch/arm/cpu/armv7/mx7ulp/clock.c
new file mode 100644
index 0000000..e6225bb
--- /dev/null
+++ b/arch/arm/cpu/armv7/mx7ulp/clock.c
@@ -0,0 +1,315 @@
+/*
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <div64.h>
+#include <asm/io.h>
+#include <errno.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/sys_proto.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int get_clocks(void)
+{
+#ifdef CONFIG_FSL_ESDHC
+#if CONFIG_SYS_FSL_ESDHC_ADDR == USDHC0_RBASE
+	gd->arch.sdhc_clk = mxc_get_clock(MXC_ESDHC_CLK);
+#elif CONFIG_SYS_FSL_ESDHC_ADDR == USDHC1_RBASE
+	gd->arch.sdhc_clk = mxc_get_clock(MXC_ESDHC2_CLK);
+#endif
+#endif
+	return 0;
+}
+
+static u32 get_fast_plat_clk(void)
+{
+	return scg_clk_get_rate(SCG_NIC0_CLK);
+}
+
+static u32 get_slow_plat_clk(void)
+{
+	return scg_clk_get_rate(SCG_NIC1_CLK);
+}
+
+static u32 get_ipg_clk(void)
+{
+	return scg_clk_get_rate(SCG_NIC1_BUS_CLK);
+}
+
+u32 get_lpuart_clk(void)
+{
+	int index = 0;
+
+	const u32 lpuart_array[] = {
+		LPUART0_RBASE,
+		LPUART1_RBASE,
+		LPUART2_RBASE,
+		LPUART3_RBASE,
+		LPUART4_RBASE,
+		LPUART5_RBASE,
+		LPUART6_RBASE,
+		LPUART7_RBASE,
+	};
+
+	const enum pcc_clk lpuart_pcc_clks[] = {
+		PER_CLK_LPUART4,
+		PER_CLK_LPUART5,
+		PER_CLK_LPUART6,
+		PER_CLK_LPUART7,
+	};
+
+	for (index = 0; index < 8; index++) {
+		if (lpuart_array[index] == LPUART_BASE)
+			break;
+	}
+
+	if (index < 4 || index > 7)
+		return 0;
+
+	return pcc_clock_get_rate(lpuart_pcc_clks[index - 4]);
+}
+
+unsigned int mxc_get_clock(enum mxc_clock clk)
+{
+	switch (clk) {
+	case MXC_ARM_CLK:
+		return scg_clk_get_rate(SCG_CORE_CLK);
+	case MXC_AXI_CLK:
+		return get_fast_plat_clk();
+	case MXC_AHB_CLK:
+		return get_slow_plat_clk();
+	case MXC_IPG_CLK:
+		return get_ipg_clk();
+	case MXC_I2C_CLK:
+		return pcc_clock_get_rate(PER_CLK_LPI2C4);
+	case MXC_UART_CLK:
+		return get_lpuart_clk();
+	case MXC_ESDHC_CLK:
+		return pcc_clock_get_rate(PER_CLK_USDHC0);
+	case MXC_ESDHC2_CLK:
+		return pcc_clock_get_rate(PER_CLK_USDHC1);
+	case MXC_DDR_CLK:
+		return scg_clk_get_rate(SCG_DDR_CLK);
+	default:
+		printf("Unsupported mxc_clock %d\n", clk);
+		break;
+	}
+
+	return 0;
+}
+
+void init_clk_usdhc(u32 index)
+{
+	switch (index) {
+	case 0:
+		/*Disable the clock before configure it */
+		pcc_clock_enable(PER_CLK_USDHC0, false);
+
+		/* 158MHz / 1 = 158MHz */
+		pcc_clock_sel(PER_CLK_USDHC0, SCG_NIC1_CLK);
+		pcc_clock_div_config(PER_CLK_USDHC0, false, 1);
+		pcc_clock_enable(PER_CLK_USDHC0, true);
+		break;
+	case 1:
+		/*Disable the clock before configure it */
+		pcc_clock_enable(PER_CLK_USDHC1, false);
+
+		/* 158MHz / 1 = 158MHz */
+		pcc_clock_sel(PER_CLK_USDHC1, SCG_NIC1_CLK);
+		pcc_clock_div_config(PER_CLK_USDHC1, false, 1);
+		pcc_clock_enable(PER_CLK_USDHC1, true);
+		break;
+	default:
+		printf("Invalid index for USDHC %d\n", index);
+		break;
+	}
+}
+
+#ifdef CONFIG_MXC_OCOTP
+
+#define OCOTP_CTRL_PCC1_SLOT		(38)
+#define OCOTP_CTRL_HIGH4K_PCC1_SLOT	(39)
+
+void enable_ocotp_clk(unsigned char enable)
+{
+	u32 val;
+
+	/*
+	 * Seems the OCOTP CLOCKs have been enabled at default,
+	 * check its inuse flag
+	 */
+
+	val = readl(PCC1_RBASE + 4 * OCOTP_CTRL_PCC1_SLOT);
+	if (!(val & PCC_INUSE_MASK))
+		writel(PCC_CGC_MASK, (PCC1_RBASE + 4 * OCOTP_CTRL_PCC1_SLOT));
+
+	val = readl(PCC1_RBASE + 4 * OCOTP_CTRL_HIGH4K_PCC1_SLOT);
+	if (!(val & PCC_INUSE_MASK))
+		writel(PCC_CGC_MASK,
+		       (PCC1_RBASE + 4 * OCOTP_CTRL_HIGH4K_PCC1_SLOT));
+}
+#endif
+
+void enable_usboh3_clk(unsigned char enable)
+{
+	if (enable) {
+		pcc_clock_enable(PER_CLK_USB0, false);
+		pcc_clock_sel(PER_CLK_USB0, SCG_NIC1_BUS_CLK);
+		pcc_clock_enable(PER_CLK_USB0, true);
+
+#ifdef CONFIG_USB_MAX_CONTROLLER_COUNT
+		if (CONFIG_USB_MAX_CONTROLLER_COUNT > 1) {
+			pcc_clock_enable(PER_CLK_USB1, false);
+			pcc_clock_sel(PER_CLK_USB1, SCG_NIC1_BUS_CLK);
+			pcc_clock_enable(PER_CLK_USB1, true);
+		}
+#endif
+
+		pcc_clock_enable(PER_CLK_USB_PHY, true);
+		pcc_clock_enable(PER_CLK_USB_PL301, true);
+	} else {
+		pcc_clock_enable(PER_CLK_USB0, false);
+		pcc_clock_enable(PER_CLK_USB1, false);
+		pcc_clock_enable(PER_CLK_USB_PHY, false);
+		pcc_clock_enable(PER_CLK_USB_PL301, false);
+	}
+}
+
+static void lpuart_set_clk(uint32_t index, enum scg_clk clk)
+{
+	const enum pcc_clk lpuart_pcc_clks[] = {
+		PER_CLK_LPUART4,
+		PER_CLK_LPUART5,
+		PER_CLK_LPUART6,
+		PER_CLK_LPUART7,
+	};
+
+	if (index < 4 || index > 7)
+		return;
+
+#ifndef CONFIG_CLK_DEBUG
+	pcc_clock_enable(lpuart_pcc_clks[index - 4], false);
+#endif
+	pcc_clock_sel(lpuart_pcc_clks[index - 4], clk);
+	pcc_clock_enable(lpuart_pcc_clks[index - 4], true);
+}
+
+static void init_clk_lpuart(void)
+{
+	u32 index = 0, i;
+
+	const u32 lpuart_array[] = {
+		LPUART0_RBASE,
+		LPUART1_RBASE,
+		LPUART2_RBASE,
+		LPUART3_RBASE,
+		LPUART4_RBASE,
+		LPUART5_RBASE,
+		LPUART6_RBASE,
+		LPUART7_RBASE,
+	};
+
+	for (i = 0; i < 8; i++) {
+		if (lpuart_array[i] == LPUART_BASE) {
+			index = i;
+			break;
+		}
+	}
+
+	lpuart_set_clk(index, SCG_SOSC_DIV2_CLK);
+}
+
+static void init_clk_rgpio2p(void)
+{
+	/*Enable RGPIO2P1 clock */
+	pcc_clock_enable(PER_CLK_RGPIO2P1, true);
+
+	/*
+	 * Hard code to enable RGPIO2P0 clock since it is not
+	 * in clock frame for A7 domain
+	 */
+	writel(PCC_CGC_MASK, (PCC0_RBASE + 0x3C));
+}
+
+/* Configure PLL/PFD freq */
+void clock_init(void)
+{
+	/*
+	 * ROM has enabled clocks:
+	 * A4 side: SIRC 16Mhz (DIV1-3 off),  FIRC 48Mhz (DIV1-2 on),
+	 *          Non-LP-boot:  SOSC, SPLL PFD0 (scs selected)
+	 * A7 side:  SPLL PFD0 (scs selected, 413Mhz),
+	 *           APLL PFD0 (352Mhz), DDRCLK, all NIC clocks
+	 *           A7 Plat0 (NIC0) = 176Mhz, Plat1 (NIC1) = 176Mhz,
+	 *           IP BUS (NIC1_BUS) = 58.6Mhz
+	 *
+	 * In u-boot:
+	 * 1. Enable PFD1-3 of APLL for A7 side. Enable FIRC and DIVs.
+	 * 2. Enable USB PLL
+	 * 3. Init the clocks of peripherals used in u-boot bu
+	 *    without set rate interface.The clocks for these
+	 *    peripherals are enabled in this intialization.
+	 * 4.Other peripherals with set clock rate interface
+	 *   does not be set in this function.
+	 */
+
+	scg_a7_firc_init();
+
+	scg_a7_soscdiv_init();
+
+	/* APLL PFD1 = 270Mhz, PFD2=480Mhz, PFD3=800Mhz */
+	scg_enable_pll_pfd(SCG_APLL_PFD1_CLK, 35);
+	scg_enable_pll_pfd(SCG_APLL_PFD2_CLK, 20);
+	scg_enable_pll_pfd(SCG_APLL_PFD3_CLK, 12);
+
+	init_clk_lpuart();
+
+	init_clk_rgpio2p();
+
+	enable_usboh3_clk(1);
+}
+
+/*
+ * Dump some core clockes.
+ */
+int do_mx7_showclocks(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	u32 addr = 0;
+	u32 freq;
+	freq = decode_pll(PLL_A7_SPLL);
+	printf("PLL_A7_SPLL    %8d MHz\n", freq / 1000000);
+
+	freq = decode_pll(PLL_A7_APLL);
+	printf("PLL_A7_APLL    %8d MHz\n", freq / 1000000);
+
+	freq = decode_pll(PLL_USB);
+	printf("PLL_USB    %8d MHz\n", freq / 1000000);
+
+	printf("\n");
+
+	printf("CORE       %8d kHz\n", scg_clk_get_rate(SCG_CORE_CLK) / 1000);
+	printf("IPG        %8d kHz\n", mxc_get_clock(MXC_IPG_CLK) / 1000);
+	printf("UART       %8d kHz\n", mxc_get_clock(MXC_UART_CLK) / 1000);
+	printf("AHB        %8d kHz\n", mxc_get_clock(MXC_AHB_CLK) / 1000);
+	printf("AXI        %8d kHz\n", mxc_get_clock(MXC_AXI_CLK) / 1000);
+	printf("DDR        %8d kHz\n", mxc_get_clock(MXC_DDR_CLK) / 1000);
+	printf("USDHC1     %8d kHz\n", mxc_get_clock(MXC_ESDHC_CLK) / 1000);
+	printf("USDHC2     %8d kHz\n", mxc_get_clock(MXC_ESDHC2_CLK) / 1000);
+	printf("I2C4       %8d kHz\n", mxc_get_clock(MXC_I2C_CLK) / 1000);
+
+	addr = (u32) clock_init;
+	printf("[%s] addr = 0x%08X\r\n", __func__, addr);
+	scg_a7_info();
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	clocks,	CONFIG_SYS_MAXARGS, 1, do_mx7_showclocks,
+	"display clocks",
+	""
+);