clk: socfpga: agilex: add clock driver for eASIC N5X platform

Add support for Intel's eASIC N5X platform. The clock manager driver for
the N5X is very similar to the Agilex platform, we can re-use most of
the Agilex clock driver.

This patch makes the necessary changes for the driver to differentiate
between the Agilex and the N5X platforms.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Link: https://lore.kernel.org/r/20210212143059.478554-2-dinguyen@kernel.org
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

1 files changed, 83 insertions, 0 deletions

diff --git a/drivers/clk/socfpga/clk-pll-s10.c b/drivers/clk/socfpga/clk-pll-s10.c
index 4e268953b7da..f6f66e08e1f4 100644
--- a/drivers/clk/socfpga/clk-pll-s10.c
+++ b/drivers/clk/socfpga/clk-pll-s10.c
@@ -27,10 +27,37 @@
 #define SWCTRLBTCLKSEL_MASK		0x200
 #define SWCTRLBTCLKSEL_SHIFT		9
 
+#define SOCFPGA_N5X_PLLDIV_FDIV_MASK	GENMASK(16, 8)
+#define SOCFPGA_N5X_PLLDIV_FDIV_SHIFT	8
+#define SOCFPGA_N5X_PLLDIV_RDIV_MASK	GENMASK(5, 0)
+#define SOCFPGA_N5X_PLLDIV_QDIV_MASK	GENMASK(26, 24)
+#define SOCFPGA_N5X_PLLDIV_QDIV_SHIFT	24
+
 #define SOCFPGA_BOOT_CLK		"boot_clk"
 
 #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
 
+static unsigned long n5x_clk_pll_recalc_rate(struct clk_hw *hwclk,
+						unsigned long parent_rate)
+{
+	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
+	unsigned long fdiv, reg, rdiv, qdiv;
+	u32 power = 1;
+
+	/* read VCO1 reg for numerator and denominator */
+	reg = readl(socfpgaclk->hw.reg + 0x8);
+	fdiv = (reg & SOCFPGA_N5X_PLLDIV_FDIV_MASK) >> SOCFPGA_N5X_PLLDIV_FDIV_SHIFT;
+	rdiv = (reg & SOCFPGA_N5X_PLLDIV_RDIV_MASK);
+	qdiv = (reg & SOCFPGA_N5X_PLLDIV_QDIV_MASK) >> SOCFPGA_N5X_PLLDIV_QDIV_SHIFT;
+
+	while (qdiv) {
+		power *= 2;
+		qdiv--;
+	}
+
+	return ((parent_rate * 2 * (fdiv + 1)) / ((rdiv + 1) * power));
+}
+
 static unsigned long agilex_clk_pll_recalc_rate(struct clk_hw *hwclk,
 						unsigned long parent_rate)
 {
@@ -123,6 +150,25 @@ static int clk_pll_prepare(struct clk_hw *hwclk)
 	return 0;
 }
 
+static int n5x_clk_pll_prepare(struct clk_hw *hwclk)
+{
+	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
+	u32 reg;
+
+	/* Bring PLL out of reset */
+	reg = readl(socfpgaclk->hw.reg + 0x4);
+	reg |= SOCFPGA_PLL_RESET_MASK;
+	writel(reg, socfpgaclk->hw.reg + 0x4);
+
+	return 0;
+}
+
+static const struct clk_ops n5x_clk_pll_ops = {
+	.recalc_rate = n5x_clk_pll_recalc_rate,
+	.get_parent = clk_pll_get_parent,
+	.prepare = n5x_clk_pll_prepare,
+};
+
 static const struct clk_ops agilex_clk_pll_ops = {
 	.recalc_rate = agilex_clk_pll_recalc_rate,
 	.get_parent = clk_pll_get_parent,
@@ -214,3 +260,40 @@ struct clk *agilex_register_pll(const struct stratix10_pll_clock *clks,
 	}
 	return clk;
 }
+
+struct clk *n5x_register_pll(const struct stratix10_pll_clock *clks,
+			     void __iomem *reg)
+{
+	struct clk *clk;
+	struct socfpga_pll *pll_clk;
+	struct clk_init_data init;
+	const char *name = clks->name;
+
+	pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
+	if (WARN_ON(!pll_clk))
+		return NULL;
+
+	pll_clk->hw.reg = reg + clks->offset;
+
+	if (streq(name, SOCFPGA_BOOT_CLK))
+		init.ops = &clk_boot_ops;
+	else
+		init.ops = &n5x_clk_pll_ops;
+
+	init.name = name;
+	init.flags = clks->flags;
+
+	init.num_parents = clks->num_parents;
+	init.parent_names = NULL;
+	init.parent_data = clks->parent_data;
+	pll_clk->hw.hw.init = &init;
+
+	pll_clk->hw.bit_idx = SOCFPGA_PLL_POWER;
+
+	clk = clk_register(NULL, &pll_clk->hw.hw);
+	if (WARN_ON(IS_ERR(clk))) {
+		kfree(pll_clk);
+		return NULL;
+	}
+	return clk;
+}