drivers: clk: Add clock driver for Intel N5X device

Add clock manager driver for N5X. Provides clock initialization
and get_rate functions.

Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>
diff --git a/drivers/clk/altera/clk-n5x.c b/drivers/clk/altera/clk-n5x.c
new file mode 100644
index 0000000..bdcbbaa
--- /dev/null
+++ b/drivers/clk/altera/clk-n5x.c
@@ -0,0 +1,489 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Intel Corporation <www.intel.com>
+ */
+
+#include <common.h>
+#include <asm/arch/clock_manager.h>
+#include <asm/global_data.h>
+#include <asm/io.h>
+#include <clk-uclass.h>
+#include <dm.h>
+#include <dm/lists.h>
+#include <dm/util.h>
+#include <dt-bindings/clock/n5x-clock.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct socfpga_clk_plat {
+	void __iomem *regs;
+};
+
+/*
+ * function to write the bypass register which requires a poll of the
+ * busy bit
+ */
+static void clk_write_bypass_mainpll(struct socfpga_clk_plat *plat, u32 val)
+{
+	CM_REG_WRITEL(plat, val, CLKMGR_MAINPLL_BYPASS);
+	cm_wait_for_fsm();
+}
+
+static void clk_write_bypass_perpll(struct socfpga_clk_plat *plat, u32 val)
+{
+	CM_REG_WRITEL(plat, val, CLKMGR_PERPLL_BYPASS);
+	cm_wait_for_fsm();
+}
+
+/* function to write the ctrl register which requires a poll of the busy bit */
+static void clk_write_ctrl(struct socfpga_clk_plat *plat, u32 val)
+{
+	CM_REG_WRITEL(plat, val, CLKMGR_CTRL);
+	cm_wait_for_fsm();
+}
+
+/*
+ * Setup clocks while making no assumptions about previous state of the clocks.
+ */
+static void clk_basic_init(struct udevice *dev,
+			   const struct cm_config * const cfg)
+{
+	struct socfpga_clk_plat *plat = dev_get_plat(dev);
+
+	if (!cfg)
+		return;
+
+#if IS_ENABLED(CONFIG_SPL_BUILD)
+	/* Always force clock manager into boot mode before any configuration */
+	clk_write_ctrl(plat,
+		       CM_REG_READL(plat, CLKMGR_CTRL) | CLKMGR_CTRL_BOOTMODE);
+#else
+	/* Skip clock configuration in SSBL if it's not in boot mode */
+	if (!(CM_REG_READL(plat, CLKMGR_CTRL) & CLKMGR_CTRL_BOOTMODE))
+		return;
+#endif
+
+	/* Put both PLLs in bypass */
+	clk_write_bypass_mainpll(plat, CLKMGR_BYPASS_MAINPLL_ALL);
+	clk_write_bypass_perpll(plat, CLKMGR_BYPASS_PERPLL_ALL);
+
+	/* Put both PLLs in Reset */
+	CM_REG_SETBITS(plat, CLKMGR_MAINPLL_PLLCTRL,
+		       CLKMGR_PLLCTRL_BYPASS_MASK);
+	CM_REG_SETBITS(plat, CLKMGR_PERPLL_PLLCTRL,
+		       CLKMGR_PLLCTRL_BYPASS_MASK);
+
+	/* setup main PLL */
+	CM_REG_WRITEL(plat, cfg->main_pll_pllglob, CLKMGR_MAINPLL_PLLGLOB);
+	CM_REG_WRITEL(plat, cfg->main_pll_plldiv, CLKMGR_MAINPLL_PLLDIV);
+	CM_REG_WRITEL(plat, cfg->main_pll_plloutdiv, CLKMGR_MAINPLL_PLLOUTDIV);
+	CM_REG_WRITEL(plat, cfg->main_pll_mpuclk, CLKMGR_MAINPLL_MPUCLK);
+	CM_REG_WRITEL(plat, cfg->main_pll_nocclk, CLKMGR_MAINPLL_NOCCLK);
+	CM_REG_WRITEL(plat, cfg->main_pll_nocdiv, CLKMGR_MAINPLL_NOCDIV);
+
+	/* setup peripheral */
+	CM_REG_WRITEL(plat, cfg->per_pll_pllglob, CLKMGR_PERPLL_PLLGLOB);
+	CM_REG_WRITEL(plat, cfg->per_pll_plldiv, CLKMGR_PERPLL_PLLDIV);
+	CM_REG_WRITEL(plat, cfg->per_pll_plloutdiv, CLKMGR_PERPLL_PLLOUTDIV);
+	CM_REG_WRITEL(plat, cfg->per_pll_emacctl, CLKMGR_PERPLL_EMACCTL);
+	CM_REG_WRITEL(plat, cfg->per_pll_gpiodiv, CLKMGR_PERPLL_GPIODIV);
+
+	/* Take both PLL out of reset and power up */
+	CM_REG_CLRBITS(plat, CLKMGR_MAINPLL_PLLCTRL,
+		       CLKMGR_PLLCTRL_BYPASS_MASK);
+	CM_REG_CLRBITS(plat, CLKMGR_PERPLL_PLLCTRL,
+		       CLKMGR_PLLCTRL_BYPASS_MASK);
+
+	cm_wait_for_lock(CLKMGR_STAT_ALLPLL_LOCKED_MASK);
+
+	CM_REG_WRITEL(plat, cfg->alt_emacactr, CLKMGR_ALTR_EMACACTR);
+	CM_REG_WRITEL(plat, cfg->alt_emacbctr, CLKMGR_ALTR_EMACBCTR);
+	CM_REG_WRITEL(plat, cfg->alt_emacptpctr, CLKMGR_ALTR_EMACPTPCTR);
+	CM_REG_WRITEL(plat, cfg->alt_gpiodbctr, CLKMGR_ALTR_GPIODBCTR);
+	CM_REG_WRITEL(plat, cfg->alt_sdmmcctr, CLKMGR_ALTR_SDMMCCTR);
+	CM_REG_WRITEL(plat, cfg->alt_s2fuser0ctr, CLKMGR_ALTR_S2FUSER0CTR);
+	CM_REG_WRITEL(plat, cfg->alt_s2fuser1ctr, CLKMGR_ALTR_S2FUSER1CTR);
+	CM_REG_WRITEL(plat, cfg->alt_psirefctr, CLKMGR_ALTR_PSIREFCTR);
+
+	/* Configure ping pong counters in altera group */
+	CM_REG_WRITEL(plat, CLKMGR_LOSTLOCK_SET_MASK, CLKMGR_MAINPLL_LOSTLOCK);
+	CM_REG_WRITEL(plat, CLKMGR_LOSTLOCK_SET_MASK, CLKMGR_PERPLL_LOSTLOCK);
+
+	CM_REG_WRITEL(plat, CM_REG_READL(plat, CLKMGR_MAINPLL_PLLGLOB) |
+			CLKMGR_PLLGLOB_CLR_LOSTLOCK_BYPASS_MASK,
+			CLKMGR_MAINPLL_PLLGLOB);
+	CM_REG_WRITEL(plat, CM_REG_READL(plat, CLKMGR_PERPLL_PLLGLOB) |
+			CLKMGR_PLLGLOB_CLR_LOSTLOCK_BYPASS_MASK,
+			CLKMGR_PERPLL_PLLGLOB);
+
+	/* Take all PLLs out of bypass */
+	clk_write_bypass_mainpll(plat, 0);
+	clk_write_bypass_perpll(plat, 0);
+
+	/* Clear the loss of lock bits */
+	CM_REG_CLRBITS(plat, CLKMGR_INTRCLR,
+		       CLKMGR_INTER_PERPLLLOST_MASK |
+		       CLKMGR_INTER_MAINPLLLOST_MASK);
+
+	/* Take all ping pong counters out of reset */
+	CM_REG_CLRBITS(plat, CLKMGR_ALTR_EXTCNTRST,
+		       CLKMGR_ALT_EXTCNTRST_ALLCNTRST_MASK);
+
+	/* Out of boot mode */
+	clk_write_ctrl(plat,
+		       CM_REG_READL(plat, CLKMGR_CTRL) & ~CLKMGR_CTRL_BOOTMODE);
+}
+
+static u32 clk_get_5_1_clk_src(struct socfpga_clk_plat *plat, u32 reg)
+{
+	u32 clksrc = CM_REG_READL(plat, reg);
+
+	return (clksrc & CLKMGR_CLKSRC_MASK) >> CLKMGR_CLKSRC_OFFSET;
+}
+
+static u64 clk_get_pll_output_hz(struct socfpga_clk_plat *plat,
+				 u32 pllglob_reg, u32 plldiv_reg)
+{
+	u64 clock = 0;
+	u32 clklsrc, divf, divr, divq, power = 1;
+
+	/* Get input clock frequency */
+	clklsrc = (CM_REG_READL(plat, pllglob_reg) &
+		   CLKMGR_PLLGLOB_VCO_PSRC_MASK) >>
+		   CLKMGR_PLLGLOB_VCO_PSRC_OFFSET;
+
+	switch (clklsrc) {
+	case CLKMGR_VCO_PSRC_EOSC1:
+		clock = cm_get_osc_clk_hz();
+		break;
+	case CLKMGR_VCO_PSRC_INTOSC:
+		clock = cm_get_intosc_clk_hz();
+		break;
+	case CLKMGR_VCO_PSRC_F2S:
+		clock = cm_get_fpga_clk_hz();
+		break;
+	}
+
+	/* Calculate pll out clock frequency */
+	divf = (CM_REG_READL(plat, plldiv_reg) &
+		CLKMGR_PLLDIV_FDIV_MASK) >>
+		CLKMGR_PLLDIV_FDIV_OFFSET;
+
+	divr = (CM_REG_READL(plat, plldiv_reg) &
+		CLKMGR_PLLDIV_REFCLKDIV_MASK) >>
+		CLKMGR_PLLDIV_REFCLKDIV_OFFSET;
+
+	divq = (CM_REG_READL(plat, plldiv_reg) &
+		CLKMGR_PLLDIV_OUTDIV_QDIV_MASK) >>
+		CLKMGR_PLLDIV_OUTDIV_QDIV_OFFSET;
+
+	while (divq) {
+		power *= 2;
+		divq--;
+	}
+
+	return (clock * 2 * (divf + 1)) / ((divr + 1) * power);
+}
+
+static u64 clk_get_clksrc_hz(struct socfpga_clk_plat *plat, u32 clksrc_reg,
+			     u32 main_div, u32 per_div)
+{
+	u64 clock = 0;
+	u32 clklsrc = clk_get_5_1_clk_src(plat, clksrc_reg);
+
+	switch (clklsrc) {
+	case CLKMGR_CLKSRC_MAIN:
+		clock = clk_get_pll_output_hz(plat,
+					      CLKMGR_MAINPLL_PLLGLOB,
+					      CLKMGR_MAINPLL_PLLDIV);
+		clock /= 1 + main_div;
+		break;
+
+	case CLKMGR_CLKSRC_PER:
+		clock = clk_get_pll_output_hz(plat,
+					      CLKMGR_PERPLL_PLLGLOB,
+					      CLKMGR_PERPLL_PLLDIV);
+		clock /= 1 + per_div;
+		break;
+
+	case CLKMGR_CLKSRC_OSC1:
+		clock = cm_get_osc_clk_hz();
+		break;
+
+	case CLKMGR_CLKSRC_INTOSC:
+		clock = cm_get_intosc_clk_hz();
+		break;
+
+	case CLKMGR_CLKSRC_FPGA:
+		clock = cm_get_fpga_clk_hz();
+		break;
+	default:
+		return 0;
+	}
+
+	return clock;
+}
+
+static u64 clk_get_mpu_clk_hz(struct socfpga_clk_plat *plat)
+{
+	u32 mainpll_c0cnt = (CM_REG_READL(plat, CLKMGR_MAINPLL_PLLOUTDIV) &
+			     CLKMGR_PLLOUTDIV_C0CNT_MASK) >>
+			     CLKMGR_PLLOUTDIV_C0CNT_OFFSET;
+
+	u32 perpll_c0cnt = (CM_REG_READL(plat, CLKMGR_PERPLL_PLLOUTDIV) &
+			    CLKMGR_PLLOUTDIV_C0CNT_MASK) >>
+			    CLKMGR_PLLOUTDIV_C0CNT_OFFSET;
+
+	u64 clock = clk_get_clksrc_hz(plat, CLKMGR_MAINPLL_MPUCLK,
+				      mainpll_c0cnt, perpll_c0cnt);
+
+	clock /= 1 + (CM_REG_READL(plat, CLKMGR_MAINPLL_MPUCLK) &
+		      CLKMGR_CLKCNT_MSK);
+
+	return clock;
+}
+
+static u32 clk_get_l3_main_clk_hz(struct socfpga_clk_plat *plat)
+{
+	u32 mainpll_c1cnt = (CM_REG_READL(plat, CLKMGR_MAINPLL_PLLOUTDIV) &
+			     CLKMGR_PLLOUTDIV_C1CNT_MASK) >>
+			     CLKMGR_PLLOUTDIV_C1CNT_OFFSET;
+
+	u32 perpll_c1cnt = (CM_REG_READL(plat, CLKMGR_PERPLL_PLLOUTDIV) &
+			    CLKMGR_PLLOUTDIV_C1CNT_MASK) >>
+			    CLKMGR_PLLOUTDIV_C1CNT_OFFSET;
+
+	return clk_get_clksrc_hz(plat, CLKMGR_MAINPLL_NOCCLK,
+				 mainpll_c1cnt, perpll_c1cnt);
+}
+
+static u32 clk_get_l4_main_clk_hz(struct socfpga_clk_plat *plat)
+{
+	u64 clock = clk_get_l3_main_clk_hz(plat);
+
+	clock /= BIT((CM_REG_READL(plat, CLKMGR_MAINPLL_NOCDIV) >>
+		      CLKMGR_NOCDIV_L4MAIN_OFFSET) &
+		      CLKMGR_NOCDIV_DIVIDER_MASK);
+
+	return clock;
+}
+
+static u32 clk_get_sdmmc_clk_hz(struct socfpga_clk_plat *plat)
+{
+	u32 mainpll_c3cnt = (CM_REG_READL(plat, CLKMGR_MAINPLL_PLLOUTDIV) &
+			     CLKMGR_PLLOUTDIV_C3CNT_MASK) >>
+			     CLKMGR_PLLOUTDIV_C3CNT_OFFSET;
+
+	u32 perpll_c3cnt = (CM_REG_READL(plat, CLKMGR_PERPLL_PLLOUTDIV) &
+			    CLKMGR_PLLOUTDIV_C3CNT_MASK) >>
+			    CLKMGR_PLLOUTDIV_C3CNT_OFFSET;
+
+	u64 clock = clk_get_clksrc_hz(plat, CLKMGR_ALTR_SDMMCCTR,
+				      mainpll_c3cnt, perpll_c3cnt);
+
+	clock /= 1 + (CM_REG_READL(plat, CLKMGR_ALTR_SDMMCCTR) &
+		      CLKMGR_CLKCNT_MSK);
+
+	return clock / 4;
+}
+
+static u32 clk_get_l4_sp_clk_hz(struct socfpga_clk_plat *plat)
+{
+	u64 clock = clk_get_l3_main_clk_hz(plat);
+
+	clock /= BIT((CM_REG_READL(plat, CLKMGR_MAINPLL_NOCDIV) >>
+		      CLKMGR_NOCDIV_L4SPCLK_OFFSET) &
+		      CLKMGR_NOCDIV_DIVIDER_MASK);
+
+	return clock;
+}
+
+static u32 clk_get_l4_mp_clk_hz(struct socfpga_clk_plat *plat)
+{
+	u64 clock = clk_get_l3_main_clk_hz(plat);
+
+	clock /= BIT((CM_REG_READL(plat, CLKMGR_MAINPLL_NOCDIV) >>
+		      CLKMGR_NOCDIV_L4MPCLK_OFFSET) &
+		      CLKMGR_NOCDIV_DIVIDER_MASK);
+
+	return clock;
+}
+
+static u32 clk_get_l4_sys_free_clk_hz(struct socfpga_clk_plat *plat)
+{
+	if (CM_REG_READL(plat, CLKMGR_STAT) & CLKMGR_STAT_BOOTMODE)
+		return clk_get_l3_main_clk_hz(plat) / 2;
+
+	return clk_get_l3_main_clk_hz(plat) / 4;
+}
+
+static u32 clk_get_emac_clk_hz(struct socfpga_clk_plat *plat, u32 emac_id)
+{
+	bool emacsel_a;
+	u32 ctl;
+	u32 ctr_reg;
+	u32 clock;
+	u32 div;
+	u32 reg;
+
+	/* Get EMAC clock source */
+	ctl = CM_REG_READL(plat, CLKMGR_PERPLL_EMACCTL);
+	if (emac_id == N5X_EMAC0_CLK)
+		ctl = (ctl >> CLKMGR_PERPLLGRP_EMACCTL_EMAC0SELB_OFFSET) &
+		       CLKMGR_PERPLLGRP_EMACCTL_EMAC0SELB_MASK;
+	else if (emac_id == N5X_EMAC1_CLK)
+		ctl = (ctl >> CLKMGR_PERPLLGRP_EMACCTL_EMAC1SELB_OFFSET) &
+		       CLKMGR_PERPLLGRP_EMACCTL_EMAC1SELB_MASK;
+	else if (emac_id == N5X_EMAC2_CLK)
+		ctl = (ctl >> CLKMGR_PERPLLGRP_EMACCTL_EMAC2SELB_OFFSET) &
+		       CLKMGR_PERPLLGRP_EMACCTL_EMAC2SELB_MASK;
+	else
+		return 0;
+
+	if (ctl) {
+		/* EMAC B source */
+		emacsel_a = false;
+		ctr_reg = CLKMGR_ALTR_EMACBCTR;
+	} else {
+		/* EMAC A source */
+		emacsel_a = true;
+		ctr_reg = CLKMGR_ALTR_EMACACTR;
+	}
+
+	reg = CM_REG_READL(plat, ctr_reg);
+	clock = (reg & CLKMGR_ALT_EMACCTR_SRC_MASK)
+		 >> CLKMGR_ALT_EMACCTR_SRC_OFFSET;
+	div = (reg & CLKMGR_ALT_EMACCTR_CNT_MASK)
+	       >> CLKMGR_ALT_EMACCTR_CNT_OFFSET;
+
+	switch (clock) {
+	case CLKMGR_CLKSRC_MAIN:
+		clock = clk_get_pll_output_hz(plat,
+					      CLKMGR_MAINPLL_PLLGLOB,
+					      CLKMGR_MAINPLL_PLLDIV);
+
+		if (emacsel_a) {
+			clock /= 1 + ((CM_REG_READL(plat,
+				       CLKMGR_MAINPLL_PLLOUTDIV) &
+				       CLKMGR_PLLOUTDIV_C2CNT_MASK) >>
+				       CLKMGR_PLLOUTDIV_C2CNT_OFFSET);
+		} else {
+			clock /= 1 + ((CM_REG_READL(plat,
+				       CLKMGR_MAINPLL_PLLOUTDIV) &
+				       CLKMGR_PLLOUTDIV_C3CNT_MASK) >>
+				       CLKMGR_PLLOUTDIV_C3CNT_OFFSET);
+		}
+		break;
+
+	case CLKMGR_CLKSRC_PER:
+		clock = clk_get_pll_output_hz(plat,
+					      CLKMGR_PERPLL_PLLGLOB,
+					      CLKMGR_PERPLL_PLLDIV);
+		if (emacsel_a) {
+			clock /= 1 + ((CM_REG_READL(plat,
+				       CLKMGR_PERPLL_PLLOUTDIV) &
+				       CLKMGR_PLLOUTDIV_C2CNT_MASK) >>
+				       CLKMGR_PLLOUTDIV_C2CNT_OFFSET);
+		} else {
+			clock /= 1 + ((CM_REG_READL(plat,
+				       CLKMGR_PERPLL_PLLOUTDIV) &
+				       CLKMGR_PLLOUTDIV_C3CNT_MASK >>
+				       CLKMGR_PLLOUTDIV_C3CNT_OFFSET));
+		}
+		break;
+
+	case CLKMGR_CLKSRC_OSC1:
+		clock = cm_get_osc_clk_hz();
+		break;
+
+	case CLKMGR_CLKSRC_INTOSC:
+		clock = cm_get_intosc_clk_hz();
+		break;
+
+	case CLKMGR_CLKSRC_FPGA:
+		clock = cm_get_fpga_clk_hz();
+		break;
+	}
+
+	clock /= 1 + div;
+
+	return clock;
+}
+
+static ulong socfpga_clk_get_rate(struct clk *clk)
+{
+	struct socfpga_clk_plat *plat = dev_get_plat(clk->dev);
+
+	switch (clk->id) {
+	case N5X_MPU_CLK:
+		return clk_get_mpu_clk_hz(plat);
+	case N5X_L4_MAIN_CLK:
+		return clk_get_l4_main_clk_hz(plat);
+	case N5X_L4_SYS_FREE_CLK:
+		return clk_get_l4_sys_free_clk_hz(plat);
+	case N5X_L4_MP_CLK:
+		return clk_get_l4_mp_clk_hz(plat);
+	case N5X_L4_SP_CLK:
+		return clk_get_l4_sp_clk_hz(plat);
+	case N5X_SDMMC_CLK:
+		return clk_get_sdmmc_clk_hz(plat);
+	case N5X_EMAC0_CLK:
+	case N5X_EMAC1_CLK:
+	case N5X_EMAC2_CLK:
+		return clk_get_emac_clk_hz(plat, clk->id);
+	case N5X_USB_CLK:
+	case N5X_NAND_X_CLK:
+		return clk_get_l4_mp_clk_hz(plat);
+	case N5X_NAND_CLK:
+		return clk_get_l4_mp_clk_hz(plat) / 4;
+	default:
+		return -ENXIO;
+	}
+}
+
+static int socfpga_clk_enable(struct clk *clk)
+{
+	return 0;
+}
+
+static int socfpga_clk_probe(struct udevice *dev)
+{
+	const struct cm_config *cm_default_cfg = cm_get_default_config();
+
+	clk_basic_init(dev, cm_default_cfg);
+
+	return 0;
+}
+
+static int socfpga_clk_of_to_plat(struct udevice *dev)
+{
+	struct socfpga_clk_plat *plat = dev_get_plat(dev);
+	fdt_addr_t addr;
+
+	addr = devfdt_get_addr(dev);
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+	plat->regs = (void __iomem *)addr;
+
+	return 0;
+}
+
+static struct clk_ops socfpga_clk_ops = {
+	.enable		= socfpga_clk_enable,
+	.get_rate	= socfpga_clk_get_rate,
+};
+
+static const struct udevice_id socfpga_clk_match[] = {
+	{ .compatible = "intel,n5x-clkmgr" },
+	{}
+};
+
+U_BOOT_DRIVER(socfpga_n5x_clk) = {
+	.name		= "clk-n5x",
+	.id		= UCLASS_CLK,
+	.of_match	= socfpga_clk_match,
+	.ops		= &socfpga_clk_ops,
+	.probe		= socfpga_clk_probe,
+	.of_to_plat	= socfpga_clk_of_to_plat,
+	.plat_auto	= sizeof(struct socfpga_clk_plat),
+};