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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/sh/kernel/cpu/sh4/clock-sh4-202.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/sh/kernel/cpu/sh4/clock-sh4-202.c')
-rw-r--r--arch/sh/kernel/cpu/sh4/clock-sh4-202.c174
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/sh4/clock-sh4-202.c b/arch/sh/kernel/cpu/sh4/clock-sh4-202.c
new file mode 100644
index 000000000..c1cdef763
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/clock-sh4-202.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/sh/kernel/cpu/sh4/clock-sh4-202.c
+ *
+ * Additional SH4-202 support for the clock framework
+ *
+ * Copyright (C) 2005 Paul Mundt
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clkdev.h>
+#include <asm/clock.h>
+#include <asm/freq.h>
+
+#define CPG2_FRQCR3 0xfe0a0018
+
+static int frqcr3_divisors[] = { 1, 2, 3, 4, 6, 8, 16 };
+static int frqcr3_values[] = { 0, 1, 2, 3, 4, 5, 6 };
+
+static unsigned long emi_clk_recalc(struct clk *clk)
+{
+ int idx = __raw_readl(CPG2_FRQCR3) & 0x0007;
+ return clk->parent->rate / frqcr3_divisors[idx];
+}
+
+static inline int frqcr3_lookup(struct clk *clk, unsigned long rate)
+{
+ int divisor = clk->parent->rate / rate;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(frqcr3_divisors); i++)
+ if (frqcr3_divisors[i] == divisor)
+ return frqcr3_values[i];
+
+ /* Safe fallback */
+ return 5;
+}
+
+static struct sh_clk_ops sh4202_emi_clk_ops = {
+ .recalc = emi_clk_recalc,
+};
+
+static struct clk sh4202_emi_clk = {
+ .flags = CLK_ENABLE_ON_INIT,
+ .ops = &sh4202_emi_clk_ops,
+};
+
+static unsigned long femi_clk_recalc(struct clk *clk)
+{
+ int idx = (__raw_readl(CPG2_FRQCR3) >> 3) & 0x0007;
+ return clk->parent->rate / frqcr3_divisors[idx];
+}
+
+static struct sh_clk_ops sh4202_femi_clk_ops = {
+ .recalc = femi_clk_recalc,
+};
+
+static struct clk sh4202_femi_clk = {
+ .flags = CLK_ENABLE_ON_INIT,
+ .ops = &sh4202_femi_clk_ops,
+};
+
+static void shoc_clk_init(struct clk *clk)
+{
+ int i;
+
+ /*
+ * For some reason, the shoc_clk seems to be set to some really
+ * insane value at boot (values outside of the allowable frequency
+ * range for instance). We deal with this by scaling it back down
+ * to something sensible just in case.
+ *
+ * Start scaling from the high end down until we find something
+ * that passes rate verification..
+ */
+ for (i = 0; i < ARRAY_SIZE(frqcr3_divisors); i++) {
+ int divisor = frqcr3_divisors[i];
+
+ if (clk->ops->set_rate(clk, clk->parent->rate / divisor) == 0)
+ break;
+ }
+
+ WARN_ON(i == ARRAY_SIZE(frqcr3_divisors)); /* Undefined clock */
+}
+
+static unsigned long shoc_clk_recalc(struct clk *clk)
+{
+ int idx = (__raw_readl(CPG2_FRQCR3) >> 6) & 0x0007;
+ return clk->parent->rate / frqcr3_divisors[idx];
+}
+
+static int shoc_clk_verify_rate(struct clk *clk, unsigned long rate)
+{
+ struct clk *bclk = clk_get(NULL, "bus_clk");
+ unsigned long bclk_rate = clk_get_rate(bclk);
+
+ clk_put(bclk);
+
+ if (rate > bclk_rate)
+ return 1;
+ if (rate > 66000000)
+ return 1;
+
+ return 0;
+}
+
+static int shoc_clk_set_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned long frqcr3;
+ unsigned int tmp;
+
+ /* Make sure we have something sensible to switch to */
+ if (shoc_clk_verify_rate(clk, rate) != 0)
+ return -EINVAL;
+
+ tmp = frqcr3_lookup(clk, rate);
+
+ frqcr3 = __raw_readl(CPG2_FRQCR3);
+ frqcr3 &= ~(0x0007 << 6);
+ frqcr3 |= tmp << 6;
+ __raw_writel(frqcr3, CPG2_FRQCR3);
+
+ clk->rate = clk->parent->rate / frqcr3_divisors[tmp];
+
+ return 0;
+}
+
+static struct sh_clk_ops sh4202_shoc_clk_ops = {
+ .init = shoc_clk_init,
+ .recalc = shoc_clk_recalc,
+ .set_rate = shoc_clk_set_rate,
+};
+
+static struct clk sh4202_shoc_clk = {
+ .flags = CLK_ENABLE_ON_INIT,
+ .ops = &sh4202_shoc_clk_ops,
+};
+
+static struct clk *sh4202_onchip_clocks[] = {
+ &sh4202_emi_clk,
+ &sh4202_femi_clk,
+ &sh4202_shoc_clk,
+};
+
+static struct clk_lookup lookups[] = {
+ /* main clocks */
+ CLKDEV_CON_ID("emi_clk", &sh4202_emi_clk),
+ CLKDEV_CON_ID("femi_clk", &sh4202_femi_clk),
+ CLKDEV_CON_ID("shoc_clk", &sh4202_shoc_clk),
+};
+
+int __init arch_clk_init(void)
+{
+ struct clk *clk;
+ int i, ret = 0;
+
+ cpg_clk_init();
+
+ clk = clk_get(NULL, "master_clk");
+ for (i = 0; i < ARRAY_SIZE(sh4202_onchip_clocks); i++) {
+ struct clk *clkp = sh4202_onchip_clocks[i];
+
+ clkp->parent = clk;
+ ret |= clk_register(clkp);
+ }
+
+ clk_put(clk);
+
+ clkdev_add_table(lookups, ARRAY_SIZE(lookups));
+
+ return ret;
+}