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Subject[PATCH v15 3/5] clk: imx: Add SCCG PLL type
Date
From: Lucas Stach <l.stach@pengutronix.de>

The SCCG is a new PLL type introduced on i.MX8.

The description of this SCCG clock can be found here:

https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
---
drivers/clk/imx/Makefile | 3 +-
drivers/clk/imx/clk-sccg-pll.c | 256 +++++++++++++++++++++++++++++++++++++++++
drivers/clk/imx/clk.h | 9 ++
3 files changed, 267 insertions(+), 1 deletion(-)
create mode 100644 drivers/clk/imx/clk-sccg-pll.c

diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile
index 4893c1f..b87513c 100644
--- a/drivers/clk/imx/Makefile
+++ b/drivers/clk/imx/Makefile
@@ -12,7 +12,8 @@ obj-y += \
clk-pllv1.o \
clk-pllv2.o \
clk-pllv3.o \
- clk-pfd.o
+ clk-pfd.o \
+ clk-sccg-pll.o

obj-$(CONFIG_SOC_IMX1) += clk-imx1.o
obj-$(CONFIG_SOC_IMX21) += clk-imx21.o
diff --git a/drivers/clk/imx/clk-sccg-pll.c b/drivers/clk/imx/clk-sccg-pll.c
new file mode 100644
index 0000000..ee7752b
--- /dev/null
+++ b/drivers/clk/imx/clk-sccg-pll.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Copyright 2018 NXP.
+ *
+ * This driver supports the SCCG plls found in the imx8m SOCs
+ *
+ * Documentation for this SCCG pll can be found at:
+ * https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/iopoll.h>
+#include <linux/slab.h>
+#include <linux/bitfield.h>
+
+#include "clk.h"
+
+/* PLL CFGs */
+#define PLL_CFG0 0x0
+#define PLL_CFG1 0x4
+#define PLL_CFG2 0x8
+
+#define PLL_DIVF1_MASK GENMASK(18, 13)
+#define PLL_DIVF2_MASK GENMASK(12, 7)
+#define PLL_DIVR1_MASK GENMASK(27, 25)
+#define PLL_DIVR2_MASK GENMASK(24, 19)
+#define PLL_REF_MASK GENMASK(2, 0)
+
+#define PLL_LOCK_MASK BIT(31)
+#define PLL_PD_MASK BIT(7)
+
+#define OSC_25M 25000000
+#define OSC_27M 27000000
+
+#define PLL_SCCG_LOCK_TIMEOUT 70
+
+struct clk_sccg_pll {
+ struct clk_hw hw;
+ void __iomem *base;
+};
+
+#define to_clk_sccg_pll(_hw) container_of(_hw, struct clk_sccg_pll, hw)
+
+static int clk_pll_wait_lock(struct clk_sccg_pll *pll)
+{
+ u32 val;
+
+ return readl_poll_timeout(pll->base, val, val & PLL_LOCK_MASK, 0,
+ PLL_SCCG_LOCK_TIMEOUT);
+}
+
+static int clk_pll1_is_prepared(struct clk_hw *hw)
+{
+ struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
+ u32 val;
+
+ val = readl_relaxed(pll->base + PLL_CFG0);
+ return (val & PLL_PD_MASK) ? 0 : 1;
+}
+
+static unsigned long clk_pll1_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
+ u32 val, divf;
+
+ val = readl_relaxed(pll->base + PLL_CFG2);
+ divf = FIELD_GET(PLL_DIVF1_MASK, val);
+
+ return parent_rate * 2 * (divf + 1);
+}
+
+static long clk_pll1_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ unsigned long parent_rate = *prate;
+ u32 div;
+
+ if (!parent_rate)
+ return 0;
+
+ div = rate / (parent_rate * 2);
+
+ return parent_rate * div * 2;
+}
+
+static int clk_pll1_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
+ u32 val;
+ u32 divf;
+
+ if (!parent_rate)
+ return -EINVAL;
+
+ divf = rate / (parent_rate * 2);
+
+ val = readl_relaxed(pll->base + PLL_CFG2);
+ val &= ~PLL_DIVF1_MASK;
+ val |= FIELD_PREP(PLL_DIVF1_MASK, divf - 1);
+ writel_relaxed(val, pll->base + PLL_CFG2);
+
+ return clk_pll_wait_lock(pll);
+}
+
+static int clk_pll1_prepare(struct clk_hw *hw)
+{
+ struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
+ u32 val;
+
+ val = readl_relaxed(pll->base + PLL_CFG0);
+ val &= ~PLL_PD_MASK;
+ writel_relaxed(val, pll->base + PLL_CFG0);
+
+ return clk_pll_wait_lock(pll);
+}
+
+static void clk_pll1_unprepare(struct clk_hw *hw)
+{
+ struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
+ u32 val;
+
+ val = readl_relaxed(pll->base + PLL_CFG0);
+ val |= PLL_PD_MASK;
+ writel_relaxed(val, pll->base + PLL_CFG0);
+
+}
+
+static unsigned long clk_pll2_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
+ u32 val, ref, divr1, divf1, divr2, divf2;
+ u64 temp64;
+
+ val = readl_relaxed(pll->base + PLL_CFG0);
+ switch (FIELD_GET(PLL_REF_MASK, val)) {
+ case 0:
+ ref = OSC_25M;
+ break;
+ case 1:
+ ref = OSC_27M;
+ break;
+ default:
+ ref = OSC_25M;
+ break;
+ }
+
+ val = readl_relaxed(pll->base + PLL_CFG2);
+ divr1 = FIELD_GET(PLL_DIVR1_MASK, val);
+ divr2 = FIELD_GET(PLL_DIVR2_MASK, val);
+ divf1 = FIELD_GET(PLL_DIVF1_MASK, val);
+ divf2 = FIELD_GET(PLL_DIVF2_MASK, val);
+
+ temp64 = ref * 2;
+ temp64 *= (divf1 + 1) * (divf2 + 1);
+
+ do_div(temp64, (divr1 + 1) * (divr2 + 1));
+
+ return temp64;
+}
+
+static long clk_pll2_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ u32 div;
+ unsigned long parent_rate = *prate;
+
+ if (!parent_rate)
+ return 0;
+
+ div = rate / parent_rate;
+
+ return parent_rate * div;
+}
+
+static int clk_pll2_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ u32 val;
+ u32 divf;
+ struct clk_sccg_pll *pll = to_clk_sccg_pll(hw);
+
+ if (!parent_rate)
+ return -EINVAL;
+
+ divf = rate / parent_rate;
+
+ val = readl_relaxed(pll->base + PLL_CFG2);
+ val &= ~PLL_DIVF2_MASK;
+ val |= FIELD_PREP(PLL_DIVF2_MASK, divf - 1);
+ writel_relaxed(val, pll->base + PLL_CFG2);
+
+ return clk_pll_wait_lock(pll);
+}
+
+static const struct clk_ops clk_sccg_pll1_ops = {
+ .is_prepared = clk_pll1_is_prepared,
+ .recalc_rate = clk_pll1_recalc_rate,
+ .round_rate = clk_pll1_round_rate,
+ .set_rate = clk_pll1_set_rate,
+};
+
+static const struct clk_ops clk_sccg_pll2_ops = {
+ .prepare = clk_pll1_prepare,
+ .unprepare = clk_pll1_unprepare,
+ .recalc_rate = clk_pll2_recalc_rate,
+ .round_rate = clk_pll2_round_rate,
+ .set_rate = clk_pll2_set_rate,
+};
+
+struct clk *imx_clk_sccg_pll(const char *name,
+ const char *parent_name,
+ void __iomem *base,
+ enum imx_sccg_pll_type pll_type)
+{
+ struct clk_sccg_pll *pll;
+ struct clk_init_data init;
+ struct clk_hw *hw;
+ int ret;
+
+ switch (pll_type) {
+ case SCCG_PLL1:
+ init.ops = &clk_sccg_pll1_ops;
+ break;
+ case SCCG_PLL2:
+ init.ops = &clk_sccg_pll2_ops;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+ if (!pll)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.flags = 0;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ pll->base = base;
+ pll->hw.init = &init;
+
+ hw = &pll->hw;
+
+ ret = clk_hw_register(NULL, hw);
+ if (ret) {
+ kfree(pll);
+ return ERR_PTR(ret);
+ }
+
+ return hw->clk;
+}
diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
index 44a1f14..864cd8a 100644
--- a/drivers/clk/imx/clk.h
+++ b/drivers/clk/imx/clk.h
@@ -21,6 +21,11 @@ enum imx_pllv1_type {
IMX_PLLV1_IMX35,
};

+enum imx_sccg_pll_type {
+ SCCG_PLL1,
+ SCCG_PLL2,
+};
+
struct clk *imx_clk_pllv1(enum imx_pllv1_type type, const char *name,
const char *parent, void __iomem *base);

@@ -30,6 +35,10 @@ struct clk *imx_clk_pllv2(const char *name, const char *parent,
struct clk *imx_clk_frac_pll(const char *name, const char *parent_name,
void __iomem *base);

+struct clk *imx_clk_sccg_pll(const char *name, const char *parent_name,
+ void __iomem *base,
+ enum imx_sccg_pll_type pll_type);
+
enum imx_pllv3_type {
IMX_PLLV3_GENERIC,
IMX_PLLV3_SYS,
--
2.7.4
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