[PATCH v4 3/4] clk: loongson1: Re-implement the clock driver
From: Keguang Zhang
Date: Mon Mar 20 2023 - 06:43:12 EST
Re-implement the clock driver for Loongson-1 to
add devicetree support and fit into the clock framework.
Signed-off-by: Keguang Zhang <keguang.zhang@xxxxxxxxx>
---
V3 -> V4: Fix the build error of missing linux/module.h
V2 -> V3: Add MODULE_AUTHOR and MODULE_DESCRIPTION info
V1 -> V2: Implement one clock controller instead of single clocks
(suggested by Krzysztof Kozlowski)
---
drivers/clk/Makefile | 1 +
drivers/clk/clk-loongson1.c | 302 ++++++++++++++++++++++++++++++++++++
2 files changed, 303 insertions(+)
create mode 100644 drivers/clk/clk-loongson1.c
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index b7b2c6d64636..417bc27ab6e8 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_COMMON_CLK_K210) += clk-k210.o
obj-$(CONFIG_LMK04832) += clk-lmk04832.o
obj-$(CONFIG_COMMON_CLK_LAN966X) += clk-lan966x.o
obj-$(CONFIG_COMMON_CLK_LOCHNAGAR) += clk-lochnagar.o
+obj-$(CONFIG_MACH_LOONGSON32) += clk-loongson1.o
obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
obj-$(CONFIG_COMMON_CLK_MAX9485) += clk-max9485.o
obj-$(CONFIG_ARCH_MILBEAUT_M10V) += clk-milbeaut.o
diff --git a/drivers/clk/clk-loongson1.c b/drivers/clk/clk-loongson1.c
new file mode 100644
index 000000000000..4369c10bf7bb
--- /dev/null
+++ b/drivers/clk/clk-loongson1.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Clock driver for Loongson-1 SoC
+ *
+ * Copyright (C) 2012-2023 Keguang Zhang <keguang.zhang@xxxxxxxxx>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/clock/loongson,ls1x-clk.h>
+
+/* Loongson 1 Clock Register Definitions */
+#define CLK_PLL_FREQ 0x0
+#define CLK_PLL_DIV 0x4
+
+static DEFINE_SPINLOCK(ls1x_clk_div_lock);
+
+struct ls1x_clk_pll_data {
+ u32 fixed;
+ u8 shift;
+ u8 int_shift;
+ u8 int_width;
+ u8 frac_shift;
+ u8 frac_width;
+};
+
+struct ls1x_clk_div_data {
+ u8 shift;
+ u8 width;
+ unsigned long flags;
+ const struct clk_div_table *table;
+ u8 bypass_shift;
+ u8 bypass_inv;
+ spinlock_t *lock; /* protect access to DIV registers */
+};
+
+struct ls1x_clk {
+ void __iomem *reg;
+ unsigned int offset;
+ struct clk_hw hw;
+ void *data;
+};
+
+#define to_ls1x_clk(_hw) container_of(_hw, struct ls1x_clk, hw)
+
+static inline unsigned long ls1x_pll_rate_part(unsigned int val,
+ unsigned int shift,
+ unsigned int width)
+{
+ return (val & GENMASK(shift + width, shift)) >> shift;
+}
+
+static unsigned long ls1x_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ls1x_clk *ls1x_clk = to_ls1x_clk(hw);
+ const struct ls1x_clk_pll_data *d = ls1x_clk->data;
+ u32 val, rate;
+
+ val = readl(ls1x_clk->reg);
+ rate = d->fixed;
+ rate += ls1x_pll_rate_part(val, d->int_shift, d->int_width);
+ if (d->frac_width)
+ rate += ls1x_pll_rate_part(val, d->frac_shift, d->frac_width);
+ rate *= parent_rate;
+ rate >>= d->shift;
+
+ return rate;
+}
+
+static const struct clk_ops ls1x_pll_clk_ops = {
+ .recalc_rate = ls1x_pll_recalc_rate,
+};
+
+static unsigned long ls1x_divider_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ls1x_clk *ls1x_clk = to_ls1x_clk(hw);
+ const struct ls1x_clk_div_data *d = ls1x_clk->data;
+ unsigned int val;
+
+ val = readl(ls1x_clk->reg) >> d->shift;
+ val &= clk_div_mask(d->width);
+
+ return divider_recalc_rate(hw, parent_rate, val, d->table,
+ d->flags, d->width);
+}
+
+static long ls1x_divider_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct ls1x_clk *ls1x_clk = to_ls1x_clk(hw);
+ const struct ls1x_clk_div_data *d = ls1x_clk->data;
+
+ return divider_round_rate(hw, rate, prate, d->table,
+ d->width, d->flags);
+}
+
+static int ls1x_divider_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ls1x_clk *ls1x_clk = to_ls1x_clk(hw);
+ const struct ls1x_clk_div_data *d = ls1x_clk->data;
+ int val, div_val;
+ unsigned long flags = 0;
+
+ div_val = divider_get_val(rate, parent_rate, d->table,
+ d->width, d->flags);
+ if (div_val < 0)
+ return div_val;
+
+ if (d->lock)
+ spin_lock_irqsave(d->lock, flags);
+ else
+ __acquire(d->lock);
+
+ /* Bypass the clock */
+ val = readl(ls1x_clk->reg);
+ if (d->bypass_inv)
+ val &= ~BIT(d->bypass_shift);
+ else
+ val |= BIT(d->bypass_shift);
+ writel(val, ls1x_clk->reg);
+
+ val = readl(ls1x_clk->reg);
+ val &= ~(clk_div_mask(d->width) << d->shift);
+ val |= (u32)div_val << d->shift;
+ writel(val, ls1x_clk->reg);
+
+ /* Restore the clock */
+ val = readl(ls1x_clk->reg);
+ if (d->bypass_inv)
+ val |= BIT(d->bypass_shift);
+ else
+ val &= ~BIT(d->bypass_shift);
+ writel(val, ls1x_clk->reg);
+
+ if (d->lock)
+ spin_unlock_irqrestore(d->lock, flags);
+ else
+ __release(d->lock);
+
+ return 0;
+}
+
+static const struct clk_ops ls1x_clk_divider_ops = {
+ .recalc_rate = ls1x_divider_recalc_rate,
+ .round_rate = ls1x_divider_round_rate,
+ .set_rate = ls1x_divider_set_rate,
+};
+
+#define LS1X_CLK_PLL(_name, _offset, _fixed, _shift, \
+ f_shift, f_width, i_shift, i_width) \
+struct ls1x_clk _name = { \
+ .offset = (_offset), \
+ .data = &(struct ls1x_clk_pll_data) { \
+ .fixed = (_fixed), \
+ .shift = (_shift), \
+ .int_shift = (i_shift), \
+ .int_width = (i_width), \
+ .frac_shift = (f_shift), \
+ .frac_width = (f_width), \
+ }, \
+ .hw.init = &(struct clk_init_data) { \
+ .name = #_name, \
+ .ops = &ls1x_pll_clk_ops, \
+ .parent_data = &(const struct clk_parent_data) { \
+ .fw_name = "xtal", \
+ .name = "xtal", \
+ .index = -1, \
+ }, \
+ .num_parents = 1, \
+ }, \
+}
+
+#define LS1X_CLK_DIV(_name, _pname, _offset, _shift, _width, \
+ _table, _bypass_shift, _bypass_inv, _flags) \
+struct ls1x_clk _name = { \
+ .offset = (_offset), \
+ .data = &(struct ls1x_clk_div_data){ \
+ .shift = (_shift), \
+ .width = (_width), \
+ .table = (_table), \
+ .flags = (_flags), \
+ .bypass_shift = (_bypass_shift), \
+ .bypass_inv = (_bypass_inv), \
+ .lock = &ls1x_clk_div_lock, \
+ }, \
+ .hw.init = &(struct clk_init_data) { \
+ .name = #_name, \
+ .ops = &ls1x_clk_divider_ops, \
+ .parent_hws = (const struct clk_hw *[]) { _pname }, \
+ .num_parents = 1, \
+ .flags = CLK_GET_RATE_NOCACHE, \
+ }, \
+}
+
+static LS1X_CLK_PLL(ls1b_clk_pll, CLK_PLL_FREQ, 12, 1, 0, 5, 0, 0);
+static LS1X_CLK_DIV(ls1b_clk_cpu, &ls1b_clk_pll.hw, CLK_PLL_DIV,
+ 20, 4, NULL, 8, 0,
+ CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ROUND_CLOSEST);
+static LS1X_CLK_DIV(ls1b_clk_dc, &ls1b_clk_pll.hw, CLK_PLL_DIV,
+ 26, 4, NULL, 12, 0, CLK_DIVIDER_ONE_BASED);
+static LS1X_CLK_DIV(ls1b_clk_ahb, &ls1b_clk_pll.hw, CLK_PLL_DIV,
+ 14, 4, NULL, 10, 0, CLK_DIVIDER_ONE_BASED);
+static CLK_FIXED_FACTOR(ls1b_clk_apb, "ls1b_clk_apb", "ls1b_clk_ahb", 2, 1,
+ CLK_SET_RATE_PARENT);
+
+static struct clk_hw_onecell_data ls1b_clk_hw_data = {
+ .hws = {
+ [LS1X_CLKID_PLL] = &ls1b_clk_pll.hw,
+ [LS1X_CLKID_CPU] = &ls1b_clk_cpu.hw,
+ [LS1X_CLKID_DC] = &ls1b_clk_dc.hw,
+ [LS1X_CLKID_AHB] = &ls1b_clk_ahb.hw,
+ [LS1X_CLKID_APB] = &ls1b_clk_apb.hw,
+ [CLK_NR_CLKS] = NULL,
+ },
+ .num = CLK_NR_CLKS,
+};
+
+static const struct clk_div_table ls1c_ahb_div_table[] = {
+ [0] = { .val = 0, .div = 2 },
+ [1] = { .val = 1, .div = 4 },
+ [2] = { .val = 2, .div = 3 },
+ [3] = { .val = 3, .div = 3 },
+ [4] = { /* sentinel */ }
+};
+
+static LS1X_CLK_PLL(ls1c_clk_pll, CLK_PLL_FREQ, 0, 2, 8, 8, 16, 8);
+static LS1X_CLK_DIV(ls1c_clk_cpu, &ls1c_clk_pll.hw, CLK_PLL_DIV,
+ 8, 7, NULL, 0, 1,
+ CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ROUND_CLOSEST);
+static LS1X_CLK_DIV(ls1c_clk_dc, &ls1c_clk_pll.hw, CLK_PLL_DIV,
+ 24, 7, NULL, 4, 1, CLK_DIVIDER_ONE_BASED);
+static LS1X_CLK_DIV(ls1c_clk_ahb, &ls1c_clk_cpu.hw, CLK_PLL_FREQ,
+ 0, 2, ls1c_ahb_div_table, 0, 0, CLK_DIVIDER_ALLOW_ZERO);
+static CLK_FIXED_FACTOR(ls1c_clk_apb, "ls1c_clk_apb", "ls1c_clk_ahb", 1, 1,
+ CLK_SET_RATE_PARENT);
+
+static struct clk_hw_onecell_data ls1c_clk_hw_data = {
+ .hws = {
+ [LS1X_CLKID_PLL] = &ls1c_clk_pll.hw,
+ [LS1X_CLKID_CPU] = &ls1c_clk_cpu.hw,
+ [LS1X_CLKID_DC] = &ls1c_clk_dc.hw,
+ [LS1X_CLKID_AHB] = &ls1c_clk_ahb.hw,
+ [LS1X_CLKID_APB] = &ls1c_clk_apb.hw,
+ [CLK_NR_CLKS] = NULL,
+ },
+ .num = CLK_NR_CLKS,
+};
+
+static void __init ls1x_clk_init(struct device_node *np,
+ struct clk_hw_onecell_data *hw_data)
+{
+ struct ls1x_clk *ls1x_clk;
+ void __iomem *reg;
+ int i, ret;
+
+ reg = of_iomap(np, 0);
+ if (!reg) {
+ pr_err("Unable to map base for %pOF\n", np);
+ return;
+ }
+
+ for (i = 0; i < CLK_NR_CLKS; i++) {
+ /* array might be sparse */
+ if (!hw_data->hws[i])
+ continue;
+
+ if (i != LS1X_CLKID_APB) {
+ ls1x_clk = to_ls1x_clk(hw_data->hws[i]);
+ ls1x_clk->reg = reg + ls1x_clk->offset;
+ }
+
+ ret = of_clk_hw_register(np, hw_data->hws[i]);
+ if (ret)
+ return;
+ }
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, hw_data);
+ if (ret)
+ pr_err("Failed to register %pOF\n", np);
+}
+
+static void __init ls1b_clk_init(struct device_node *np)
+{
+ return ls1x_clk_init(np, &ls1b_clk_hw_data);
+}
+
+static void __init ls1c_clk_init(struct device_node *np)
+{
+ return ls1x_clk_init(np, &ls1c_clk_hw_data);
+}
+
+CLK_OF_DECLARE(ls1b_clk, "loongson,ls1b-clk", ls1b_clk_init);
+CLK_OF_DECLARE(ls1c_clk, "loongson,ls1c-clk", ls1c_clk_init);
+
+MODULE_AUTHOR("Keguang Zhang <keguang.zhang@xxxxxxxxx>");
+MODULE_DESCRIPTION("Loongson1 clock driver");
--
2.34.1