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path: root/drivers/clk/samsung/clk.c
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-rw-r--r--drivers/clk/samsung/clk.c320
1 files changed, 320 insertions, 0 deletions
diff --git a/drivers/clk/samsung/clk.c b/drivers/clk/samsung/clk.c
new file mode 100644
index 000000000000..cd3c40ab50f3
--- /dev/null
+++ b/drivers/clk/samsung/clk.c
@@ -0,0 +1,320 @@
+/*
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2013 Linaro Ltd.
+ * Author: Thomas Abraham <thomas.ab@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This file includes utility functions to register clocks to common
+ * clock framework for Samsung platforms.
+*/
+
+#include <linux/syscore_ops.h>
+#include "clk.h"
+
+static DEFINE_SPINLOCK(lock);
+static struct clk **clk_table;
+static void __iomem *reg_base;
+#ifdef CONFIG_OF
+static struct clk_onecell_data clk_data;
+#endif
+
+#ifdef CONFIG_PM_SLEEP
+static struct samsung_clk_reg_dump *reg_dump;
+static unsigned long nr_reg_dump;
+
+static int samsung_clk_suspend(void)
+{
+ struct samsung_clk_reg_dump *rd = reg_dump;
+ unsigned long i;
+
+ for (i = 0; i < nr_reg_dump; i++, rd++)
+ rd->value = __raw_readl(reg_base + rd->offset);
+
+ return 0;
+}
+
+static void samsung_clk_resume(void)
+{
+ struct samsung_clk_reg_dump *rd = reg_dump;
+ unsigned long i;
+
+ for (i = 0; i < nr_reg_dump; i++, rd++)
+ __raw_writel(rd->value, reg_base + rd->offset);
+}
+
+static struct syscore_ops samsung_clk_syscore_ops = {
+ .suspend = samsung_clk_suspend,
+ .resume = samsung_clk_resume,
+};
+#endif /* CONFIG_PM_SLEEP */
+
+/* setup the essentials required to support clock lookup using ccf */
+void __init samsung_clk_init(struct device_node *np, void __iomem *base,
+ unsigned long nr_clks, unsigned long *rdump,
+ unsigned long nr_rdump, unsigned long *soc_rdump,
+ unsigned long nr_soc_rdump)
+{
+ reg_base = base;
+
+#ifdef CONFIG_PM_SLEEP
+ if (rdump && nr_rdump) {
+ unsigned int idx;
+ reg_dump = kzalloc(sizeof(struct samsung_clk_reg_dump)
+ * (nr_rdump + nr_soc_rdump), GFP_KERNEL);
+ if (!reg_dump) {
+ pr_err("%s: memory alloc for register dump failed\n",
+ __func__);
+ return;
+ }
+
+ for (idx = 0; idx < nr_rdump; idx++)
+ reg_dump[idx].offset = rdump[idx];
+ for (idx = 0; idx < nr_soc_rdump; idx++)
+ reg_dump[nr_rdump + idx].offset = soc_rdump[idx];
+ nr_reg_dump = nr_rdump + nr_soc_rdump;
+ register_syscore_ops(&samsung_clk_syscore_ops);
+ }
+#endif
+
+ clk_table = kzalloc(sizeof(struct clk *) * nr_clks, GFP_KERNEL);
+ if (!clk_table)
+ panic("could not allocate clock lookup table\n");
+
+ if (!np)
+ return;
+
+#ifdef CONFIG_OF
+ clk_data.clks = clk_table;
+ clk_data.clk_num = nr_clks;
+ of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
+#endif
+}
+
+/* add a clock instance to the clock lookup table used for dt based lookup */
+void samsung_clk_add_lookup(struct clk *clk, unsigned int id)
+{
+ if (clk_table && id)
+ clk_table[id] = clk;
+}
+
+/* register a list of aliases */
+void __init samsung_clk_register_alias(struct samsung_clock_alias *list,
+ unsigned int nr_clk)
+{
+ struct clk *clk;
+ unsigned int idx, ret;
+
+ if (!clk_table) {
+ pr_err("%s: clock table missing\n", __func__);
+ return;
+ }
+
+ for (idx = 0; idx < nr_clk; idx++, list++) {
+ if (!list->id) {
+ pr_err("%s: clock id missing for index %d\n", __func__,
+ idx);
+ continue;
+ }
+
+ clk = clk_table[list->id];
+ if (!clk) {
+ pr_err("%s: failed to find clock %d\n", __func__,
+ list->id);
+ continue;
+ }
+
+ ret = clk_register_clkdev(clk, list->alias, list->dev_name);
+ if (ret)
+ pr_err("%s: failed to register lookup %s\n",
+ __func__, list->alias);
+ }
+}
+
+/* register a list of fixed clocks */
+void __init samsung_clk_register_fixed_rate(
+ struct samsung_fixed_rate_clock *list, unsigned int nr_clk)
+{
+ struct clk *clk;
+ unsigned int idx, ret;
+
+ for (idx = 0; idx < nr_clk; idx++, list++) {
+ clk = clk_register_fixed_rate(NULL, list->name,
+ list->parent_name, list->flags, list->fixed_rate);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register clock %s\n", __func__,
+ list->name);
+ continue;
+ }
+
+ samsung_clk_add_lookup(clk, list->id);
+
+ /*
+ * Unconditionally add a clock lookup for the fixed rate clocks.
+ * There are not many of these on any of Samsung platforms.
+ */
+ ret = clk_register_clkdev(clk, list->name, NULL);
+ if (ret)
+ pr_err("%s: failed to register clock lookup for %s",
+ __func__, list->name);
+ }
+}
+
+/* register a list of fixed factor clocks */
+void __init samsung_clk_register_fixed_factor(
+ struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
+{
+ struct clk *clk;
+ unsigned int idx;
+
+ for (idx = 0; idx < nr_clk; idx++, list++) {
+ clk = clk_register_fixed_factor(NULL, list->name,
+ list->parent_name, list->flags, list->mult, list->div);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register clock %s\n", __func__,
+ list->name);
+ continue;
+ }
+
+ samsung_clk_add_lookup(clk, list->id);
+ }
+}
+
+/* register a list of mux clocks */
+void __init samsung_clk_register_mux(struct samsung_mux_clock *list,
+ unsigned int nr_clk)
+{
+ struct clk *clk;
+ unsigned int idx, ret;
+
+ for (idx = 0; idx < nr_clk; idx++, list++) {
+ clk = clk_register_mux(NULL, list->name, list->parent_names,
+ list->num_parents, list->flags, reg_base + list->offset,
+ list->shift, list->width, list->mux_flags, &lock);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register clock %s\n", __func__,
+ list->name);
+ continue;
+ }
+
+ samsung_clk_add_lookup(clk, list->id);
+
+ /* register a clock lookup only if a clock alias is specified */
+ if (list->alias) {
+ ret = clk_register_clkdev(clk, list->alias,
+ list->dev_name);
+ if (ret)
+ pr_err("%s: failed to register lookup %s\n",
+ __func__, list->alias);
+ }
+ }
+}
+
+/* register a list of div clocks */
+void __init samsung_clk_register_div(struct samsung_div_clock *list,
+ unsigned int nr_clk)
+{
+ struct clk *clk;
+ unsigned int idx, ret;
+
+ for (idx = 0; idx < nr_clk; idx++, list++) {
+ if (list->table)
+ clk = clk_register_divider_table(NULL, list->name,
+ list->parent_name, list->flags,
+ reg_base + list->offset, list->shift,
+ list->width, list->div_flags,
+ list->table, &lock);
+ else
+ clk = clk_register_divider(NULL, list->name,
+ list->parent_name, list->flags,
+ reg_base + list->offset, list->shift,
+ list->width, list->div_flags, &lock);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register clock %s\n", __func__,
+ list->name);
+ continue;
+ }
+
+ samsung_clk_add_lookup(clk, list->id);
+
+ /* register a clock lookup only if a clock alias is specified */
+ if (list->alias) {
+ ret = clk_register_clkdev(clk, list->alias,
+ list->dev_name);
+ if (ret)
+ pr_err("%s: failed to register lookup %s\n",
+ __func__, list->alias);
+ }
+ }
+}
+
+/* register a list of gate clocks */
+void __init samsung_clk_register_gate(struct samsung_gate_clock *list,
+ unsigned int nr_clk)
+{
+ struct clk *clk;
+ unsigned int idx, ret;
+
+ for (idx = 0; idx < nr_clk; idx++, list++) {
+ clk = clk_register_gate(NULL, list->name, list->parent_name,
+ list->flags, reg_base + list->offset,
+ list->bit_idx, list->gate_flags, &lock);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register clock %s\n", __func__,
+ list->name);
+ continue;
+ }
+
+ /* register a clock lookup only if a clock alias is specified */
+ if (list->alias) {
+ ret = clk_register_clkdev(clk, list->alias,
+ list->dev_name);
+ if (ret)
+ pr_err("%s: failed to register lookup %s\n",
+ __func__, list->alias);
+ }
+
+ samsung_clk_add_lookup(clk, list->id);
+ }
+}
+
+/*
+ * obtain the clock speed of all external fixed clock sources from device
+ * tree and register it
+ */
+#ifdef CONFIG_OF
+void __init samsung_clk_of_register_fixed_ext(
+ struct samsung_fixed_rate_clock *fixed_rate_clk,
+ unsigned int nr_fixed_rate_clk,
+ struct of_device_id *clk_matches)
+{
+ const struct of_device_id *match;
+ struct device_node *np;
+ u32 freq;
+
+ for_each_matching_node_and_match(np, clk_matches, &match) {
+ if (of_property_read_u32(np, "clock-frequency", &freq))
+ continue;
+ fixed_rate_clk[(u32)match->data].fixed_rate = freq;
+ }
+ samsung_clk_register_fixed_rate(fixed_rate_clk, nr_fixed_rate_clk);
+}
+#endif
+
+/* utility function to get the rate of a specified clock */
+unsigned long _get_rate(const char *clk_name)
+{
+ struct clk *clk;
+ unsigned long rate;
+
+ clk = clk_get(NULL, clk_name);
+ if (IS_ERR(clk)) {
+ pr_err("%s: could not find clock %s\n", __func__, clk_name);
+ return 0;
+ }
+ rate = clk_get_rate(clk);
+ clk_put(clk);
+ return rate;
+}