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Message-Id: <1374068732-13894-1-git-send-email-b.brezillon@overkiz.com>
Date: Wed, 17 Jul 2013 15:45:31 +0200
From: Boris BREZILLON <b.brezillon@...rkiz.com>
To: Nicolas Ferre <nicolas.ferre@...el.com>,
Ludovic Desroches <ludovic.desroches@...el.com>,
Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>,
Mike Turquette <mturquette@...aro.org>
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
Boris BREZILLON <b.brezillon@...rkiz.com>
Subject: [PATCH v2 05/42] ARM: at91: add PMC system clocks
This is the at91 system clock implementation using common clk framework.
Some peripheral needs to enable a "system" clock in order to work properly.
Each system clock is given an id which is the bit offset used in SCER/SCDR
registers.
Signed-off-by: Boris BREZILLON <b.brezillon@...rkiz.com>
---
drivers/clk/at91/Makefile | 1 +
drivers/clk/at91/clk-system.c | 184 +++++++++++++++++++++++++++++++++++++++++
include/linux/clk/at91.h | 3 +
3 files changed, 188 insertions(+)
create mode 100644 drivers/clk/at91/clk-system.c
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index d41f616..13e5714 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -3,3 +3,4 @@
#
obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o
+obj-y += clk-system.o
diff --git a/drivers/clk/at91/clk-system.c b/drivers/clk/at91/clk-system.c
new file mode 100644
index 0000000..17e092a
--- /dev/null
+++ b/drivers/clk/at91/clk-system.c
@@ -0,0 +1,184 @@
+/*
+ * drivers/clk/at91/clk-system.c
+ *
+ * Copyright (C) 2013 Boris BREZILLON <b.brezillon@...rkiz.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/at91.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+
+#define SYSTEM_MAX 32
+
+#define to_clk_system(hw) container_of(hw, struct clk_system, hw)
+struct clk_system {
+ struct clk_hw hw;
+ u8 id;
+};
+
+static int clk_system_enable(struct clk_hw *hw)
+{
+ struct clk_system *sys = to_clk_system(hw);
+ at91_pmc_write(AT91_PMC_SCER, 1 << sys->id);
+ return 0;
+}
+
+static void clk_system_disable(struct clk_hw *hw)
+{
+ struct clk_system *sys = to_clk_system(hw);
+ at91_pmc_write(AT91_PMC_SCDR, 1 << sys->id);
+}
+
+static int clk_system_is_enabled(struct clk_hw *hw)
+{
+ struct clk_system *sys = to_clk_system(hw);
+ return !!(at91_pmc_read(AT91_PMC_SCSR) & (1 << sys->id));
+}
+
+static const struct clk_ops system_ops = {
+ .enable = clk_system_enable,
+ .disable = clk_system_disable,
+ .is_enabled = clk_system_is_enabled,
+};
+
+struct clk * __init
+at91_clk_register_system(const char *name, u8 id)
+{
+ struct clk_system *sys;
+ struct clk *clk = NULL;
+ struct clk_init_data init;
+
+ id &= 31;
+
+ sys = kzalloc(sizeof(*sys), GFP_KERNEL);
+ if (!sys)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &system_ops;
+ init.parent_names = NULL;
+ init.num_parents = 0;
+ /*
+ * CLK_IGNORE_UNUSED is used to avoid ddrck switch off.
+ * TODO : we should implement a driver supporting at91 ddr controller
+ * (see drivers/memory) which would request and enable the ddrck clock.
+ * When this is done we will be able to remove CLK_IGNORE_UNUSED flag.
+ */
+ init.flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED;
+
+ sys->id = id;
+ sys->hw.init = &init;
+
+ clk = clk_register(NULL, &sys->hw);
+
+ if (IS_ERR(clk))
+ kfree(sys);
+
+ return clk;
+}
+
+#if defined(CONFIG_OF)
+struct clk_system_data {
+ struct clk **clks;
+ u8 *ids;
+ unsigned int clk_num;
+};
+
+static struct clk * __init
+of_clk_src_system_get(struct of_phandle_args *clkspec, void *data)
+{
+ struct clk_system_data *clk_data = data;
+ unsigned int id = clkspec->args[0];
+ int i;
+
+ if (id >= SYSTEM_MAX)
+ goto err;
+
+ for (i = 0; i < clk_data->clk_num; i++) {
+ if (clk_data->ids[i] == id)
+ return clk_data->clks[i];
+ }
+
+err:
+ pr_err("%s: invalid clock id %d\n", __func__, id);
+ return ERR_PTR(-EINVAL);
+}
+
+static void __init
+of_at91_clk_sys_setup(struct device_node *np)
+{
+ int i;
+ int num;
+ u32 id;
+ struct clk *clk;
+ u8 *ids;
+ struct clk **clks;
+ struct clk_system_data *clktab;
+ const char *name;
+ struct device_node *sysclknp;
+
+ num = of_get_child_count(np);
+ if (num > SYSTEM_MAX)
+ return;
+
+ clktab = kzalloc(sizeof(*clktab), GFP_KERNEL);
+ if (!clktab)
+ return;
+
+ ids = kzalloc(num * sizeof(*ids), GFP_KERNEL);
+ if (!ids)
+ goto out_free_clktab;
+
+ clks = kzalloc(num * sizeof(*clks), GFP_KERNEL);
+ if (!clks)
+ goto out_free_ids;
+
+ i = 0;
+ for_each_child_of_node(np, sysclknp) {
+ name = sysclknp->name;
+
+ if (of_property_read_u32(sysclknp, "id", &id))
+ goto out_free_clks;
+ if (id >= SYSTEM_MAX)
+ goto out_free_clks;
+
+ clk = at91_clk_register_system(name, id);
+ if (IS_ERR(clk))
+ goto out_free_clks;
+
+ clks[i] = clk;
+ ids[i] = id;
+
+ i++;
+ }
+
+ clktab->clk_num = num;
+ clktab->clks = clks;
+ clktab->ids = ids;
+ of_clk_add_provider(np, of_clk_src_system_get, clktab);
+ return;
+
+out_free_clks:
+ kfree(clks);
+out_free_ids:
+ kfree(ids);
+out_free_clktab:
+ kfree(clktab);
+}
+
+static void __init of_at91rm9200_clk_sys_setup(struct device_node *np)
+{
+ of_at91_clk_sys_setup(np);
+}
+CLK_OF_DECLARE(at91rm9200_clk_sys, "atmel,at91rm9200-clk-system",
+ of_at91rm9200_clk_sys_setup);
+#endif
diff --git a/include/linux/clk/at91.h b/include/linux/clk/at91.h
index 324134c..518a568 100644
--- a/include/linux/clk/at91.h
+++ b/include/linux/clk/at91.h
@@ -259,4 +259,7 @@ at91_clk_register_master(const char *name, int num_parents,
struct clk_master_characteristics *characteristics);
+struct clk * __init
+at91_clk_register_system(const char *name, u8 id);
+
#endif
--
1.7.9.5
--
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