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path: root/drivers/clk/bcm/clk-iproc-asiu.c
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-rw-r--r--drivers/clk/bcm/clk-iproc-asiu.c261
1 files changed, 261 insertions, 0 deletions
diff --git a/drivers/clk/bcm/clk-iproc-asiu.c b/drivers/clk/bcm/clk-iproc-asiu.c
new file mode 100644
index 000000000..dcacf55c5
--- /dev/null
+++ b/drivers/clk/bcm/clk-iproc-asiu.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2014 Broadcom Corporation
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/clkdev.h>
+#include <linux/of_address.h>
+#include <linux/delay.h>
+
+#include "clk-iproc.h"
+
+struct iproc_asiu;
+
+struct iproc_asiu_clk {
+ struct clk_hw hw;
+ const char *name;
+ struct iproc_asiu *asiu;
+ unsigned long rate;
+ struct iproc_asiu_div div;
+ struct iproc_asiu_gate gate;
+};
+
+struct iproc_asiu {
+ void __iomem *div_base;
+ void __iomem *gate_base;
+
+ struct clk_hw_onecell_data *clk_data;
+ struct iproc_asiu_clk *clks;
+};
+
+#define to_asiu_clk(hw) container_of(hw, struct iproc_asiu_clk, hw)
+
+static int iproc_asiu_clk_enable(struct clk_hw *hw)
+{
+ struct iproc_asiu_clk *clk = to_asiu_clk(hw);
+ struct iproc_asiu *asiu = clk->asiu;
+ u32 val;
+
+ /* some clocks at the ASIU level are always enabled */
+ if (clk->gate.offset == IPROC_CLK_INVALID_OFFSET)
+ return 0;
+
+ val = readl(asiu->gate_base + clk->gate.offset);
+ val |= (1 << clk->gate.en_shift);
+ writel(val, asiu->gate_base + clk->gate.offset);
+
+ return 0;
+}
+
+static void iproc_asiu_clk_disable(struct clk_hw *hw)
+{
+ struct iproc_asiu_clk *clk = to_asiu_clk(hw);
+ struct iproc_asiu *asiu = clk->asiu;
+ u32 val;
+
+ /* some clocks at the ASIU level are always enabled */
+ if (clk->gate.offset == IPROC_CLK_INVALID_OFFSET)
+ return;
+
+ val = readl(asiu->gate_base + clk->gate.offset);
+ val &= ~(1 << clk->gate.en_shift);
+ writel(val, asiu->gate_base + clk->gate.offset);
+}
+
+static unsigned long iproc_asiu_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct iproc_asiu_clk *clk = to_asiu_clk(hw);
+ struct iproc_asiu *asiu = clk->asiu;
+ u32 val;
+ unsigned int div_h, div_l;
+
+ if (parent_rate == 0) {
+ clk->rate = 0;
+ return 0;
+ }
+
+ /* if clock divisor is not enabled, simply return parent rate */
+ val = readl(asiu->div_base + clk->div.offset);
+ if ((val & (1 << clk->div.en_shift)) == 0) {
+ clk->rate = parent_rate;
+ return parent_rate;
+ }
+
+ /* clock rate = parent rate / (high_div + 1) + (low_div + 1) */
+ div_h = (val >> clk->div.high_shift) & bit_mask(clk->div.high_width);
+ div_h++;
+ div_l = (val >> clk->div.low_shift) & bit_mask(clk->div.low_width);
+ div_l++;
+
+ clk->rate = parent_rate / (div_h + div_l);
+ pr_debug("%s: rate: %lu. parent rate: %lu div_h: %u div_l: %u\n",
+ __func__, clk->rate, parent_rate, div_h, div_l);
+
+ return clk->rate;
+}
+
+static long iproc_asiu_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ unsigned int div;
+
+ if (rate == 0 || *parent_rate == 0)
+ return -EINVAL;
+
+ if (rate == *parent_rate)
+ return *parent_rate;
+
+ div = DIV_ROUND_CLOSEST(*parent_rate, rate);
+ if (div < 2)
+ return *parent_rate;
+
+ return *parent_rate / div;
+}
+
+static int iproc_asiu_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct iproc_asiu_clk *clk = to_asiu_clk(hw);
+ struct iproc_asiu *asiu = clk->asiu;
+ unsigned int div, div_h, div_l;
+ u32 val;
+
+ if (rate == 0 || parent_rate == 0)
+ return -EINVAL;
+
+ /* simply disable the divisor if one wants the same rate as parent */
+ if (rate == parent_rate) {
+ val = readl(asiu->div_base + clk->div.offset);
+ val &= ~(1 << clk->div.en_shift);
+ writel(val, asiu->div_base + clk->div.offset);
+ return 0;
+ }
+
+ div = DIV_ROUND_CLOSEST(parent_rate, rate);
+ if (div < 2)
+ return -EINVAL;
+
+ div_h = div_l = div >> 1;
+ div_h--;
+ div_l--;
+
+ val = readl(asiu->div_base + clk->div.offset);
+ val |= 1 << clk->div.en_shift;
+ if (div_h) {
+ val &= ~(bit_mask(clk->div.high_width)
+ << clk->div.high_shift);
+ val |= div_h << clk->div.high_shift;
+ } else {
+ val &= ~(bit_mask(clk->div.high_width)
+ << clk->div.high_shift);
+ }
+ if (div_l) {
+ val &= ~(bit_mask(clk->div.low_width) << clk->div.low_shift);
+ val |= div_l << clk->div.low_shift;
+ } else {
+ val &= ~(bit_mask(clk->div.low_width) << clk->div.low_shift);
+ }
+ writel(val, asiu->div_base + clk->div.offset);
+
+ return 0;
+}
+
+static const struct clk_ops iproc_asiu_ops = {
+ .enable = iproc_asiu_clk_enable,
+ .disable = iproc_asiu_clk_disable,
+ .recalc_rate = iproc_asiu_clk_recalc_rate,
+ .round_rate = iproc_asiu_clk_round_rate,
+ .set_rate = iproc_asiu_clk_set_rate,
+};
+
+void __init iproc_asiu_setup(struct device_node *node,
+ const struct iproc_asiu_div *div,
+ const struct iproc_asiu_gate *gate,
+ unsigned int num_clks)
+{
+ int i, ret;
+ struct iproc_asiu *asiu;
+
+ if (WARN_ON(!gate || !div))
+ return;
+
+ asiu = kzalloc(sizeof(*asiu), GFP_KERNEL);
+ if (WARN_ON(!asiu))
+ return;
+
+ asiu->clk_data = kzalloc(struct_size(asiu->clk_data, hws, num_clks),
+ GFP_KERNEL);
+ if (WARN_ON(!asiu->clk_data))
+ goto err_clks;
+ asiu->clk_data->num = num_clks;
+
+ asiu->clks = kcalloc(num_clks, sizeof(*asiu->clks), GFP_KERNEL);
+ if (WARN_ON(!asiu->clks))
+ goto err_asiu_clks;
+
+ asiu->div_base = of_iomap(node, 0);
+ if (WARN_ON(!asiu->div_base))
+ goto err_iomap_div;
+
+ asiu->gate_base = of_iomap(node, 1);
+ if (WARN_ON(!asiu->gate_base))
+ goto err_iomap_gate;
+
+ for (i = 0; i < num_clks; i++) {
+ struct clk_init_data init;
+ const char *parent_name;
+ struct iproc_asiu_clk *asiu_clk;
+ const char *clk_name;
+
+ ret = of_property_read_string_index(node, "clock-output-names",
+ i, &clk_name);
+ if (WARN_ON(ret))
+ goto err_clk_register;
+
+ asiu_clk = &asiu->clks[i];
+ asiu_clk->name = clk_name;
+ asiu_clk->asiu = asiu;
+ asiu_clk->div = div[i];
+ asiu_clk->gate = gate[i];
+ init.name = clk_name;
+ init.ops = &iproc_asiu_ops;
+ init.flags = 0;
+ parent_name = of_clk_get_parent_name(node, 0);
+ init.parent_names = (parent_name ? &parent_name : NULL);
+ init.num_parents = (parent_name ? 1 : 0);
+ asiu_clk->hw.init = &init;
+
+ ret = clk_hw_register(NULL, &asiu_clk->hw);
+ if (WARN_ON(ret))
+ goto err_clk_register;
+ asiu->clk_data->hws[i] = &asiu_clk->hw;
+ }
+
+ ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get,
+ asiu->clk_data);
+ if (WARN_ON(ret))
+ goto err_clk_register;
+
+ return;
+
+err_clk_register:
+ while (--i >= 0)
+ clk_hw_unregister(asiu->clk_data->hws[i]);
+ iounmap(asiu->gate_base);
+
+err_iomap_gate:
+ iounmap(asiu->div_base);
+
+err_iomap_div:
+ kfree(asiu->clks);
+
+err_asiu_clks:
+ kfree(asiu->clk_data);
+
+err_clks:
+ kfree(asiu);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 02:06:12 +0000