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path: root/drivers/clk/renesas/rcar-cpg-lib.c
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-rw-r--r--drivers/clk/renesas/rcar-cpg-lib.c270
1 files changed, 270 insertions, 0 deletions
diff --git a/drivers/clk/renesas/rcar-cpg-lib.c b/drivers/clk/renesas/rcar-cpg-lib.c
new file mode 100644
index 000000000000..7e7e5d1341d5
--- /dev/null
+++ b/drivers/clk/renesas/rcar-cpg-lib.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * R-Car Gen3 Clock Pulse Generator Library
+ *
+ * Copyright (C) 2015-2018 Glider bvba
+ * Copyright (C) 2019 Renesas Electronics Corp.
+ *
+ * Based on clk-rcar-gen3.c
+ *
+ * Copyright (C) 2015 Renesas Electronics Corp.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#include "rcar-cpg-lib.h"
+
+spinlock_t cpg_lock;
+
+void cpg_reg_modify(void __iomem *reg, u32 clear, u32 set)
+{
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&cpg_lock, flags);
+ val = readl(reg);
+ val &= ~clear;
+ val |= set;
+ writel(val, reg);
+ spin_unlock_irqrestore(&cpg_lock, flags);
+};
+
+static int cpg_simple_notifier_call(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct cpg_simple_notifier *csn =
+ container_of(nb, struct cpg_simple_notifier, nb);
+
+ switch (action) {
+ case PM_EVENT_SUSPEND:
+ csn->saved = readl(csn->reg);
+ return NOTIFY_OK;
+
+ case PM_EVENT_RESUME:
+ writel(csn->saved, csn->reg);
+ return NOTIFY_OK;
+ }
+ return NOTIFY_DONE;
+}
+
+void cpg_simple_notifier_register(struct raw_notifier_head *notifiers,
+ struct cpg_simple_notifier *csn)
+{
+ csn->nb.notifier_call = cpg_simple_notifier_call;
+ raw_notifier_chain_register(notifiers, &csn->nb);
+}
+
+/*
+ * SDn Clock
+ */
+#define CPG_SD_STP_HCK BIT(9)
+#define CPG_SD_STP_CK BIT(8)
+
+#define CPG_SD_STP_MASK (CPG_SD_STP_HCK | CPG_SD_STP_CK)
+#define CPG_SD_FC_MASK (0x7 << 2 | 0x3 << 0)
+
+#define CPG_SD_DIV_TABLE_DATA(stp_hck, sd_srcfc, sd_fc, sd_div) \
+{ \
+ .val = ((stp_hck) ? CPG_SD_STP_HCK : 0) | \
+ ((sd_srcfc) << 2) | \
+ ((sd_fc) << 0), \
+ .div = (sd_div), \
+}
+
+struct sd_div_table {
+ u32 val;
+ unsigned int div;
+};
+
+struct sd_clock {
+ struct clk_hw hw;
+ const struct sd_div_table *div_table;
+ struct cpg_simple_notifier csn;
+ unsigned int div_num;
+ unsigned int cur_div_idx;
+};
+
+/* SDn divider
+ * sd_srcfc sd_fc div
+ * stp_hck (div) (div) = sd_srcfc x sd_fc
+ *---------------------------------------------------------
+ * 0 0 (1) 1 (4) 4 : SDR104 / HS200 / HS400 (8 TAP)
+ * 0 1 (2) 1 (4) 8 : SDR50
+ * 1 2 (4) 1 (4) 16 : HS / SDR25
+ * 1 3 (8) 1 (4) 32 : NS / SDR12
+ * 1 4 (16) 1 (4) 64
+ * 0 0 (1) 0 (2) 2
+ * 0 1 (2) 0 (2) 4 : SDR104 / HS200 / HS400 (4 TAP)
+ * 1 2 (4) 0 (2) 8
+ * 1 3 (8) 0 (2) 16
+ * 1 4 (16) 0 (2) 32
+ *
+ * NOTE: There is a quirk option to ignore the first row of the dividers
+ * table when searching for suitable settings. This is because HS400 on
+ * early ES versions of H3 and M3-W requires a specific setting to work.
+ */
+static const struct sd_div_table cpg_sd_div_table[] = {
+/* CPG_SD_DIV_TABLE_DATA(stp_hck, sd_srcfc, sd_fc, sd_div) */
+ CPG_SD_DIV_TABLE_DATA(0, 0, 1, 4),
+ CPG_SD_DIV_TABLE_DATA(0, 1, 1, 8),
+ CPG_SD_DIV_TABLE_DATA(1, 2, 1, 16),
+ CPG_SD_DIV_TABLE_DATA(1, 3, 1, 32),
+ CPG_SD_DIV_TABLE_DATA(1, 4, 1, 64),
+ CPG_SD_DIV_TABLE_DATA(0, 0, 0, 2),
+ CPG_SD_DIV_TABLE_DATA(0, 1, 0, 4),
+ CPG_SD_DIV_TABLE_DATA(1, 2, 0, 8),
+ CPG_SD_DIV_TABLE_DATA(1, 3, 0, 16),
+ CPG_SD_DIV_TABLE_DATA(1, 4, 0, 32),
+};
+
+#define to_sd_clock(_hw) container_of(_hw, struct sd_clock, hw)
+
+static int cpg_sd_clock_enable(struct clk_hw *hw)
+{
+ struct sd_clock *clock = to_sd_clock(hw);
+
+ cpg_reg_modify(clock->csn.reg, CPG_SD_STP_MASK,
+ clock->div_table[clock->cur_div_idx].val &
+ CPG_SD_STP_MASK);
+
+ return 0;
+}
+
+static void cpg_sd_clock_disable(struct clk_hw *hw)
+{
+ struct sd_clock *clock = to_sd_clock(hw);
+
+ cpg_reg_modify(clock->csn.reg, 0, CPG_SD_STP_MASK);
+}
+
+static int cpg_sd_clock_is_enabled(struct clk_hw *hw)
+{
+ struct sd_clock *clock = to_sd_clock(hw);
+
+ return !(readl(clock->csn.reg) & CPG_SD_STP_MASK);
+}
+
+static unsigned long cpg_sd_clock_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct sd_clock *clock = to_sd_clock(hw);
+
+ return DIV_ROUND_CLOSEST(parent_rate,
+ clock->div_table[clock->cur_div_idx].div);
+}
+
+static int cpg_sd_clock_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ unsigned long best_rate = ULONG_MAX, diff_min = ULONG_MAX;
+ struct sd_clock *clock = to_sd_clock(hw);
+ unsigned long calc_rate, diff;
+ unsigned int i;
+
+ for (i = 0; i < clock->div_num; i++) {
+ calc_rate = DIV_ROUND_CLOSEST(req->best_parent_rate,
+ clock->div_table[i].div);
+ if (calc_rate < req->min_rate || calc_rate > req->max_rate)
+ continue;
+
+ diff = calc_rate > req->rate ? calc_rate - req->rate
+ : req->rate - calc_rate;
+ if (diff < diff_min) {
+ best_rate = calc_rate;
+ diff_min = diff;
+ }
+ }
+
+ if (best_rate == ULONG_MAX)
+ return -EINVAL;
+
+ req->rate = best_rate;
+ return 0;
+}
+
+static int cpg_sd_clock_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct sd_clock *clock = to_sd_clock(hw);
+ unsigned int i;
+
+ for (i = 0; i < clock->div_num; i++)
+ if (rate == DIV_ROUND_CLOSEST(parent_rate,
+ clock->div_table[i].div))
+ break;
+
+ if (i >= clock->div_num)
+ return -EINVAL;
+
+ clock->cur_div_idx = i;
+
+ cpg_reg_modify(clock->csn.reg, CPG_SD_STP_MASK | CPG_SD_FC_MASK,
+ clock->div_table[i].val &
+ (CPG_SD_STP_MASK | CPG_SD_FC_MASK));
+
+ return 0;
+}
+
+static const struct clk_ops cpg_sd_clock_ops = {
+ .enable = cpg_sd_clock_enable,
+ .disable = cpg_sd_clock_disable,
+ .is_enabled = cpg_sd_clock_is_enabled,
+ .recalc_rate = cpg_sd_clock_recalc_rate,
+ .determine_rate = cpg_sd_clock_determine_rate,
+ .set_rate = cpg_sd_clock_set_rate,
+};
+
+struct clk * __init cpg_sd_clk_register(const char *name,
+ void __iomem *base, unsigned int offset, const char *parent_name,
+ struct raw_notifier_head *notifiers, bool skip_first)
+{
+ struct clk_init_data init;
+ struct sd_clock *clock;
+ struct clk *clk;
+ u32 val;
+
+ clock = kzalloc(sizeof(*clock), GFP_KERNEL);
+ if (!clock)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &cpg_sd_clock_ops;
+ init.flags = CLK_SET_RATE_PARENT;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ clock->csn.reg = base + offset;
+ clock->hw.init = &init;
+ clock->div_table = cpg_sd_div_table;
+ clock->div_num = ARRAY_SIZE(cpg_sd_div_table);
+
+ if (skip_first) {
+ clock->div_table++;
+ clock->div_num--;
+ }
+
+ val = readl(clock->csn.reg) & ~CPG_SD_FC_MASK;
+ val |= CPG_SD_STP_MASK | (clock->div_table[0].val & CPG_SD_FC_MASK);
+ writel(val, clock->csn.reg);
+
+ clk = clk_register(NULL, &clock->hw);
+ if (IS_ERR(clk))
+ goto free_clock;
+
+ cpg_simple_notifier_register(notifiers, &clock->csn);
+ return clk;
+
+free_clock:
+ kfree(clock);
+ return clk;
+}
+
+
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-04 10:49:02 +0300