[U-Boot] [i.MX8MM+CCF 39/41] clk: imx: add i.MX8MM composite clk support

Peng Fan
2019-04-30T10:19:49Z

Import i.MX8MM composite clk from Linux Kernel

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
drivers/clk/imx/clk-composite-8m.c | 170 +++++++++++++++++++++++++++++++++++++
include/linux/clk-provider.h | 3 +
2 files changed, 173 insertions(+)
create mode 100644 drivers/clk/imx/clk-composite-8m.c

diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c
new file mode 100644
index 0000000000..57ebbc3bb0
--- /dev/null
+++ b/drivers/clk/imx/clk-composite-8m.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <malloc.h>
+#include <clk-uclass.h>
+#include <dm/device.h>
+#include <linux/clk-provider.h>
+#include <clk.h>
+#include "clk.h"
+
+#define UBOOT_DM_CLK_IMX_COMPOSITE "imx_clk_composite"
+
+#define PCG_PREDIV_SHIFT 16
+#define PCG_PREDIV_WIDTH 3
+#define PCG_PREDIV_MAX 8
+
+#define PCG_DIV_SHIFT 0
+#define PCG_DIV_WIDTH 6
+#define PCG_DIV_MAX 64
+
+#define PCG_PCS_SHIFT 24
+#define PCG_PCS_MASK 0x7
+
+#define PCG_CGC_SHIFT 28
+
+static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk *clk)
+{
+ struct clk_divider *divider = (struct clk_divider *)to_clk_divider(clk);
+ struct clk_composite *composite = (struct clk_composite *)clk->data;
+ ulong parent_rate = clk_get_parent_rate(&composite->clk);
+ unsigned long prediv_rate;
+ unsigned int prediv_value;
+ unsigned int div_value;
+
+ debug("%s: name %s prate: %lu reg: %p\n", __func__,
+ (&composite->clk)->dev->name, parent_rate, divider->reg);
+ prediv_value = readl(divider->reg) >> divider->shift;
+ prediv_value &= clk_div_mask(divider->width);
+
+ prediv_rate = divider_recalc_rate(clk, parent_rate, prediv_value,
+ NULL, divider->flags,
+ divider->width);
+
+ div_value = readl(divider->reg) >> PCG_DIV_SHIFT;
+ div_value &= clk_div_mask(PCG_DIV_WIDTH);
+
+ return divider_recalc_rate(clk, prediv_rate, div_value, NULL,
+ divider->flags, PCG_DIV_WIDTH);
+}
+
+static int imx8m_clk_composite_compute_dividers(unsigned long rate,
+ unsigned long parent_rate,
+ int *prediv, int *postdiv)
+{
+ int div1, div2;
+ int error = INT_MAX;
+ int ret = -EINVAL;
+
+ *prediv = 1;
+ *postdiv = 1;
+
+ for (div1 = 1; div1 <= PCG_PREDIV_MAX; div1++) {
+ for (div2 = 1; div2 <= PCG_DIV_MAX; div2++) {
+ int new_error = ((parent_rate / div1) / div2) - rate;
+
+ if (abs(new_error) < abs(error)) {
+ *prediv = div1;
+ *postdiv = div2;
+ error = new_error;
+ ret = 0;
+ }
+ }
+ }
+ return ret;
+}
+
+/*
+ * The clk are not binded to a dev, because it is part of composite clk
+ * use composite clk to get dev
+ */
+static ulong imx8m_clk_composite_divider_set_rate(struct clk *clk,
+ unsigned long rate)
+{
+ struct clk_divider *divider = (struct clk_divider *)to_clk_divider(clk);
+ struct clk_composite *composite = (struct clk_composite *)clk->data;
+ ulong parent_rate = clk_get_parent_rate(&composite->clk);
+ int prediv_value;
+ int div_value;
+ int ret;
+ u32 val;
+
+ ret = imx8m_clk_composite_compute_dividers(rate, parent_rate,
+ &prediv_value, &div_value);
+ if (ret)
+ return -EINVAL;
+
+ val = readl(divider->reg);
+ val &= ~((clk_div_mask(divider->width) << divider->shift) |
+ (clk_div_mask(PCG_DIV_WIDTH) << PCG_DIV_SHIFT));
+
+ val |= (u32)(prediv_value - 1) << divider->shift;
+ val |= (u32)(div_value - 1) << PCG_DIV_SHIFT;
+ writel(val, divider->reg);
+
+ return clk_get_rate(&composite->clk);
+}
+
+static const struct clk_ops imx8m_clk_composite_divider_ops = {
+ .get_rate = imx8m_clk_composite_divider_recalc_rate,
+ .set_rate = imx8m_clk_composite_divider_set_rate,
+};
+
+struct clk *imx8m_clk_composite_flags(const char *name,
+ const char * const *parent_names,
+ int num_parents, void __iomem *reg,
+ unsigned long flags)
+{
+ struct clk *clk = ERR_PTR(-ENOMEM);
+ struct clk_divider *div = NULL;
+ struct clk_gate *gate = NULL;
+ struct clk_mux *mux = NULL;
+
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ goto fail;
+
+ mux->reg = reg;
+ mux->shift = PCG_PCS_SHIFT;
+ mux->mask = PCG_PCS_MASK;
+ mux->num_parents = num_parents;
+ mux->flags = flags;
+ mux->parent_names = parent_names;
+
+ div = kzalloc(sizeof(*div), GFP_KERNEL);
+ if (!div)
+ goto fail;
+
+ div->reg = reg;
+ div->shift = PCG_PREDIV_SHIFT;
+ div->width = PCG_PREDIV_WIDTH;
+ div->flags = CLK_DIVIDER_ROUND_CLOSEST | flags;
+
+ gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+ if (!gate)
+ goto fail;
+
+ gate->reg = reg;
+ gate->bit_idx = PCG_CGC_SHIFT;
+ gate->flags = flags;
+
+ clk = clk_register_composite(NULL, name,
+ parent_names, num_parents,
+ &mux->clk, &clk_mux_ops, &div->clk,
+ &imx8m_clk_composite_divider_ops,
+ &gate->clk, &clk_gate_ops, flags);
+ if (IS_ERR(clk))
+ goto fail;
+
+ return clk;
+
+fail:
+ kfree(gate);
+ kfree(div);
+ kfree(mux);
+ return ERR_CAST(clk);
+}
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 490713adb6..568a0e87d6 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -102,6 +102,9 @@ struct clk_divider {
#define CLK_DIVIDER_READ_ONLY BIT(5)
#define CLK_DIVIDER_MAX_AT_ZERO BIT(6)
extern const struct clk_ops clk_divider_ops;
+unsigned long divider_recalc_rate(struct clk *hw, unsigned long parent_rate,
+ unsigned int val, const struct clk_div_table *table,
+ unsigned long flags, unsigned long width);

struct clk_fixed_factor {
struct clk clk;
--
2.16.4