drivers: clk: Add memory clock driver for Intel N5X device

Add memory clock manager driver for N5X. Provides memory clock
initialization and enable functions.

Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>

3 files changed, 221 insertions, 0 deletions

diff --git a/drivers/clk/altera/Makefile b/drivers/clk/altera/Makefile
index 38cd730..33db092 100644
--- a/drivers/clk/altera/Makefile
+++ b/drivers/clk/altera/Makefile
@@ -6,3 +6,4 @@
 obj-$(CONFIG_TARGET_SOCFPGA_AGILEX) += clk-agilex.o
 obj-$(CONFIG_TARGET_SOCFPGA_ARRIA10) += clk-arria10.o
 obj-$(CONFIG_TARGET_SOCFPGA_N5X) += clk-n5x.o
+obj-$(CONFIG_TARGET_SOCFPGA_N5X) += clk-mem-n5x.o
diff --git a/drivers/clk/altera/clk-mem-n5x.c b/drivers/clk/altera/clk-mem-n5x.c
new file mode 100644
index 0000000..ca44998
--- /dev/null
+++ b/drivers/clk/altera/clk-mem-n5x.c
@@ -0,0 +1,136 @@
+// 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-mem-n5x.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_mem_clk_plat {
+	void __iomem *regs;
+};
+
+void clk_mem_wait_for_lock(struct socfpga_mem_clk_plat *plat, u32 mask)
+{
+	u32 inter_val;
+	u32 retry = 0;
+
+	do {
+		inter_val = CM_REG_READL(plat, MEMCLKMGR_STAT) & mask;
+
+		/* Wait for stable lock */
+		if (inter_val == mask)
+			retry++;
+		else
+			retry = 0;
+
+		if (retry >= 10)
+			return;
+	} while (1);
+}
+
+/*
+ * function to write the bypass register which requires a poll of the
+ * busy bit
+ */
+void clk_mem_write_bypass_mempll(struct socfpga_mem_clk_plat *plat, u32 val)
+{
+	CM_REG_WRITEL(plat, val, MEMCLKMGR_MEMPLL_BYPASS);
+}
+
+/*
+ * Setup clocks while making no assumptions about previous state of the clocks.
+ */
+static void clk_mem_basic_init(struct udevice *dev,
+			       const struct cm_config * const cfg)
+{
+	struct socfpga_mem_clk_plat *plat = dev_get_plat(dev);
+
+	if (!cfg)
+		return;
+
+	/* Put PLLs in bypass */
+	clk_mem_write_bypass_mempll(plat, MEMCLKMGR_BYPASS_MEMPLL_ALL);
+
+	/* Put PLLs in Reset */
+	CM_REG_SETBITS(plat, MEMCLKMGR_MEMPLL_PLLCTRL,
+		       MEMCLKMGR_PLLCTRL_BYPASS_MASK);
+
+	/* setup mem PLL */
+	CM_REG_WRITEL(plat, cfg->mem_memdiv, MEMCLKMGR_MEMPLL_MEMDIV);
+	CM_REG_WRITEL(plat, cfg->mem_pllglob, MEMCLKMGR_MEMPLL_PLLGLOB);
+	CM_REG_WRITEL(plat, cfg->mem_plldiv, MEMCLKMGR_MEMPLL_PLLDIV);
+	CM_REG_WRITEL(plat, cfg->mem_plloutdiv, MEMCLKMGR_MEMPLL_PLLOUTDIV);
+
+	/* Take PLL out of reset and power up */
+	CM_REG_CLRBITS(plat, MEMCLKMGR_MEMPLL_PLLCTRL,
+		       MEMCLKMGR_PLLCTRL_BYPASS_MASK);
+}
+
+static int socfpga_mem_clk_enable(struct clk *clk)
+{
+	const struct cm_config *cm_default_cfg = cm_get_default_config();
+	struct socfpga_mem_clk_plat *plat = dev_get_plat(clk->dev);
+
+	clk_mem_basic_init(clk->dev, cm_default_cfg);
+
+	clk_mem_wait_for_lock(plat, MEMCLKMGR_STAT_ALLPLL_LOCKED_MASK);
+
+	CM_REG_WRITEL(plat, CM_REG_READL(plat, MEMCLKMGR_MEMPLL_PLLGLOB) |
+		      MEMCLKMGR_PLLGLOB_CLR_LOSTLOCK_BYPASS_MASK,
+		      MEMCLKMGR_MEMPLL_PLLGLOB);
+
+	/* Take all PLLs out of bypass */
+	clk_mem_write_bypass_mempll(plat, 0);
+
+	/* Clear the loss of lock bits (write 1 to clear) */
+	CM_REG_CLRBITS(plat, MEMCLKMGR_INTRCLR,
+		       MEMCLKMGR_INTER_MEMPLLLOST_MASK);
+
+	/* Take all ping pong counters out of reset */
+	CM_REG_CLRBITS(plat, MEMCLKMGR_MEMPLL_EXTCNTRST,
+		       MEMCLKMGR_EXTCNTRST_ALLCNTRST);
+
+	return 0;
+}
+
+static int socfpga_mem_clk_of_to_plat(struct udevice *dev)
+{
+	struct socfpga_mem_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_mem_clk_ops = {
+	.enable		= socfpga_mem_clk_enable
+};
+
+static const struct udevice_id socfpga_mem_clk_match[] = {
+	{ .compatible = "intel,n5x-mem-clkmgr" },
+	{}
+};
+
+U_BOOT_DRIVER(socfpga_n5x_mem_clk) = {
+	.name		= "mem-clk-n5x",
+	.id		= UCLASS_CLK,
+	.of_match	= socfpga_mem_clk_match,
+	.ops		= &socfpga_mem_clk_ops,
+	.of_to_plat     = socfpga_mem_clk_of_to_plat,
+	.plat_auto	= sizeof(struct socfpga_mem_clk_plat),
+};
diff --git a/drivers/clk/altera/clk-mem-n5x.h b/drivers/clk/altera/clk-mem-n5x.h
new file mode 100644
index 0000000..d000ae2
--- /dev/null
+++ b/drivers/clk/altera/clk-mem-n5x.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Intel Corporation <www.intel.com>
+ */
+
+#ifndef	_CLK_MEM_N5X_
+#define	_CLK_MEM_N5X_
+
+#ifndef __ASSEMBLY__
+#include <linux/bitops.h>
+#endif
+
+/* Clock Manager registers */
+#define MEMCLKMGR_STAT					4
+#define MEMCLKMGR_INTRGEN				8
+#define MEMCLKMGR_INTRMSK				0x0c
+#define MEMCLKMGR_INTRCLR				0x10
+#define MEMCLKMGR_INTRSTS				0x14
+#define MEMCLKMGR_INTRSTK				0x18
+#define MEMCLKMGR_INTRRAW				0x1c
+
+/* Memory Clock Manager PPL group registers */
+#define MEMCLKMGR_MEMPLL_EN				0x20
+#define MEMCLKMGR_MEMPLL_ENS				0x24
+#define MEMCLKMGR_MEMPLL_ENR				0x28
+#define MEMCLKMGR_MEMPLL_BYPASS				0x2c
+#define MEMCLKMGR_MEMPLL_BYPASSS			0x30
+#define MEMCLKMGR_MEMPLL_BYPASSR			0x34
+#define MEMCLKMGR_MEMPLL_MEMDIV				0x38
+#define MEMCLKMGR_MEMPLL_PLLGLOB			0x3c
+#define MEMCLKMGR_MEMPLL_PLLCTRL			0x40
+#define MEMCLKMGR_MEMPLL_PLLDIV				0x44
+#define MEMCLKMGR_MEMPLL_PLLOUTDIV			0x48
+#define MEMCLKMGR_MEMPLL_EXTCNTRST			0x4c
+
+#define MEMCLKMGR_CTRL_BOOTMODE				BIT(0)
+
+#define MEMCLKMGR_STAT_MEMPLL_LOCKED			BIT(8)
+
+#define MEMCLKMGR_STAT_ALLPLL_LOCKED_MASK		\
+	(MEMCLKMGR_STAT_MEMPLL_LOCKED)
+
+#define MEMCLKMGR_INTER_MEMPLLLOCKED_MASK		BIT(0)
+#define MEMCLKMGR_INTER_MEMPLLLOST_MASK			BIT(2)
+
+#define MEMCLKMGR_BYPASS_MEMPLL_ALL			0x1
+
+#define MEMCLKMGR_MEMDIV_MPFEDIV_OFFSET			0
+#define MEMCLKMGR_MEMDIV_APBDIV_OFFSET			4
+#define MEMCLKMGR_MEMDIV_DFICTRLDIV_OFFSET		8
+#define MEMCLKMGR_MEMDIV_DFIDIV_OFFSET			12
+#define MEMCLKMGR_MEMDIV_DFICTRLDIV_MASK		BIT(0)
+#define MEMCLKMGR_MEMDIV_DIVIDER_MASK			GENMASK(1, 0)
+
+#define MEMCLKMGR_PLLGLOB_PSRC_MASK			GENMASK(17, 16)
+#define MEMCLKMGR_PLLGLOB_PSRC_OFFSET			16
+#define MEMCLKMGR_PLLGLOB_LOSTLOCK_BYPASS_EN_MASK	BIT(28)
+#define MEMCLKMGR_PLLGLOB_CLR_LOSTLOCK_BYPASS_MASK	BIT(29)
+
+#define MEMCLKMGR_PSRC_EOSC1				0
+#define MEMCLKMGR_PSRC_INTOSC				1
+#define MEMCLKMGR_PSRC_F2S				2
+
+#define MEMCLKMGR_PLLCTRL_BYPASS_MASK			BIT(0)
+#define MEMCLKMGR_PLLCTRL_RST_N_MASK			BIT(1)
+
+#define MEMCLKMGR_PLLDIV_DIVR_MASK			GENMASK(5, 0)
+#define MEMCLKMGR_PLLDIV_DIVF_MASK			GENMASK(16, 8)
+#define MEMCLKMGR_PLLDIV_DIVQ_MASK			GENMASK(26, 24)
+#define MEMCLKMGR_PLLDIV_RANGE_MASK			GENMASK(30, 28)
+
+#define MEMCLKMGR_PLLDIV_DIVR_OFFSET			0
+#define MEMCLKMGR_PLLDIV_DIVF_OFFSET			8
+#define MEMCLKMGR_PLLDIV_DIVQ_QDIV_OFFSET		24
+#define MEMCLKMGR_PLLDIV_RANGE_OFFSET			28
+
+#define MEMCLKMGR_PLLOUTDIV_C0CNT_MASK			GENMASK(4, 0)
+#define MEMCLKMGR_PLLOUTDIV_C0CNT_OFFSET		0
+
+#define MEMCLKMGR_EXTCNTRST_C0CNTRST			BIT(7)
+#define MEMCLKMGR_EXTCNTRST_ALLCNTRST			\
+	(MEMCLKMGR_EXTCNTRST_C0CNTRST)
+
+#endif /* _CLK_MEM_N5X_ */