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authorPawel Moll <pawel.moll@arm.com>2012-09-18 15:17:48 +0100
committerMike Turquette <mturquette@linaro.org>2012-10-29 11:08:03 -0700
commitbcd6f569e87471d7f104bd9497f0b516a3b12e32 (patch)
treeb15f2f2b9a78232c1f70689d3d5ca35d1ed64168 /drivers/clk/versatile
parented27ff1db869cc81a92bed6defb7d107f5a156ff (diff)
downloadvexpress-lsk-bcd6f569e87471d7f104bd9497f0b516a3b12e32.tar.gz
clk: Common clocks implementation for Versatile Express
This patch adds a DT and non-DT based implementation of the common clock infrastructure for Versatile Express platform. It registers (statically or using DT) all required fixed clocks, initialises motherboard's SP810 cell (that provides clocks for SP804 timers) and explicitly registers VE "osc" driver, to make the clock generators available early. Signed-off-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/versatile')
-rw-r--r--drivers/clk/versatile/Makefile1
-rw-r--r--drivers/clk/versatile/clk-vexpress.c142
2 files changed, 143 insertions, 0 deletions
diff --git a/drivers/clk/versatile/Makefile b/drivers/clk/versatile/Makefile
index 1e49a7afcf4..c776053e5bb 100644
--- a/drivers/clk/versatile/Makefile
+++ b/drivers/clk/versatile/Makefile
@@ -2,4 +2,5 @@
obj-$(CONFIG_ICST) += clk-icst.o
obj-$(CONFIG_ARCH_INTEGRATOR) += clk-integrator.o
obj-$(CONFIG_ARCH_REALVIEW) += clk-realview.o
+obj-$(CONFIG_ARCH_VEXPRESS) += clk-vexpress.o
obj-$(CONFIG_VEXPRESS_CONFIG) += clk-vexpress-osc.o
diff --git a/drivers/clk/versatile/clk-vexpress.c b/drivers/clk/versatile/clk-vexpress.c
new file mode 100644
index 00000000000..c742ac7c60b
--- /dev/null
+++ b/drivers/clk/versatile/clk-vexpress.c
@@ -0,0 +1,142 @@
+/*
+ * 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 program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/vexpress.h>
+
+#include <asm/hardware/sp810.h>
+
+static struct clk *vexpress_sp810_timerclken[4];
+static DEFINE_SPINLOCK(vexpress_sp810_lock);
+
+static void __init vexpress_sp810_init(void __iomem *base)
+{
+ int i;
+
+ if (WARN_ON(!base))
+ return;
+
+ for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++) {
+ char name[12];
+ const char *parents[] = {
+ "v2m:refclk32khz", /* REFCLK */
+ "v2m:refclk1mhz" /* TIMCLK */
+ };
+
+ snprintf(name, ARRAY_SIZE(name), "timerclken%d", i);
+
+ vexpress_sp810_timerclken[i] = clk_register_mux(NULL, name,
+ parents, 2, 0, base + SCCTRL,
+ SCCTRL_TIMERENnSEL_SHIFT(i), 1,
+ 0, &vexpress_sp810_lock);
+
+ if (WARN_ON(IS_ERR(vexpress_sp810_timerclken[i])))
+ break;
+ }
+}
+
+
+static const char * const vexpress_clk_24mhz_periphs[] __initconst = {
+ "mb:uart0", "mb:uart1", "mb:uart2", "mb:uart3",
+ "mb:mmci", "mb:kmi0", "mb:kmi1"
+};
+
+void __init vexpress_clk_init(void __iomem *sp810_base)
+{
+ struct clk *clk;
+ int i;
+
+ clk = clk_register_fixed_rate(NULL, "dummy_apb_pclk", NULL,
+ CLK_IS_ROOT, 0);
+ WARN_ON(clk_register_clkdev(clk, "apb_pclk", NULL));
+
+ clk = clk_register_fixed_rate(NULL, "v2m:clk_24mhz", NULL,
+ CLK_IS_ROOT, 24000000);
+ for (i = 0; i < ARRAY_SIZE(vexpress_clk_24mhz_periphs); i++)
+ WARN_ON(clk_register_clkdev(clk, NULL,
+ vexpress_clk_24mhz_periphs[i]));
+
+ clk = clk_register_fixed_rate(NULL, "v2m:refclk32khz", NULL,
+ CLK_IS_ROOT, 32768);
+ WARN_ON(clk_register_clkdev(clk, NULL, "v2m:wdt"));
+
+ clk = clk_register_fixed_rate(NULL, "v2m:refclk1mhz", NULL,
+ CLK_IS_ROOT, 1000000);
+
+ vexpress_sp810_init(sp810_base);
+
+ for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
+ WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i], clk));
+
+ WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
+ "v2m-timer0", "sp804"));
+ WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
+ "v2m-timer1", "sp804"));
+}
+
+#if defined(CONFIG_OF)
+
+struct clk *vexpress_sp810_of_get(struct of_phandle_args *clkspec, void *data)
+{
+ if (WARN_ON(clkspec->args_count != 1 || clkspec->args[0] >
+ ARRAY_SIZE(vexpress_sp810_timerclken)))
+ return NULL;
+
+ return vexpress_sp810_timerclken[clkspec->args[0]];
+}
+
+static const __initconst struct of_device_id vexpress_fixed_clk_match[] = {
+ { .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
+ { .compatible = "arm,vexpress-osc", .data = vexpress_osc_of_setup, },
+ {}
+};
+
+void __init vexpress_clk_of_init(void)
+{
+ struct device_node *node;
+ struct clk *clk;
+ struct clk *refclk, *timclk;
+
+ of_clk_init(vexpress_fixed_clk_match);
+
+ node = of_find_compatible_node(NULL, NULL, "arm,sp810");
+ vexpress_sp810_init(of_iomap(node, 0));
+ of_clk_add_provider(node, vexpress_sp810_of_get, NULL);
+
+ /* Select "better" (faster) parent for SP804 timers */
+ refclk = of_clk_get_by_name(node, "refclk");
+ timclk = of_clk_get_by_name(node, "timclk");
+ if (!WARN_ON(IS_ERR(refclk) || IS_ERR(timclk))) {
+ int i = 0;
+
+ if (clk_get_rate(refclk) > clk_get_rate(timclk))
+ clk = refclk;
+ else
+ clk = timclk;
+
+ for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
+ WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i],
+ clk));
+ }
+
+ WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
+ "v2m-timer0", "sp804"));
+ WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
+ "v2m-timer1", "sp804"));
+}
+
+#endif