Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / clk / at91 / clk-system.c

diff --git a/kernel/drivers/clk/at91/clk-system.c b/kernel/drivers/clk/at91/clk-system.c
new file mode 100644 (file)
index 0000000..a76d03f
--- /dev/null
+++ b/kernel/drivers/clk/at91/clk-system.c
@@ -0,0 +1,183 @@
+/*
+ *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.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_pmc.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of_irq.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+
+#include "pmc.h"
+
+#define SYSTEM_MAX_ID          31
+
+#define SYSTEM_MAX_NAME_SZ     32
+
+#define to_clk_system(hw) container_of(hw, struct clk_system, hw)
+struct clk_system {
+       struct clk_hw hw;
+       struct at91_pmc *pmc;
+       unsigned int irq;
+       wait_queue_head_t wait;
+       u8 id;
+};
+
+static inline int is_pck(int id)
+{
+       return (id >= 8) && (id <= 15);
+}
+static irqreturn_t clk_system_irq_handler(int irq, void *dev_id)
+{
+       struct clk_system *sys = (struct clk_system *)dev_id;
+
+       wake_up(&sys->wait);
+       disable_irq_nosync(sys->irq);
+
+       return IRQ_HANDLED;
+}
+
+static int clk_system_prepare(struct clk_hw *hw)
+{
+       struct clk_system *sys = to_clk_system(hw);
+       struct at91_pmc *pmc = sys->pmc;
+       u32 mask = 1 << sys->id;
+
+       pmc_write(pmc, AT91_PMC_SCER, mask);
+
+       if (!is_pck(sys->id))
+               return 0;
+
+       while (!(pmc_read(pmc, AT91_PMC_SR) & mask)) {
+               if (sys->irq) {
+                       enable_irq(sys->irq);
+                       wait_event(sys->wait,
+                                  pmc_read(pmc, AT91_PMC_SR) & mask);
+               } else
+                       cpu_relax();
+       }
+       return 0;
+}
+
+static void clk_system_unprepare(struct clk_hw *hw)
+{
+       struct clk_system *sys = to_clk_system(hw);
+       struct at91_pmc *pmc = sys->pmc;
+
+       pmc_write(pmc, AT91_PMC_SCDR, 1 << sys->id);
+}
+
+static int clk_system_is_prepared(struct clk_hw *hw)
+{
+       struct clk_system *sys = to_clk_system(hw);
+       struct at91_pmc *pmc = sys->pmc;
+
+       if (!(pmc_read(pmc, AT91_PMC_SCSR) & (1 << sys->id)))
+               return 0;
+
+       if (!is_pck(sys->id))
+               return 1;
+
+       return !!(pmc_read(pmc, AT91_PMC_SR) & (1 << sys->id));
+}
+
+static const struct clk_ops system_ops = {
+       .prepare = clk_system_prepare,
+       .unprepare = clk_system_unprepare,
+       .is_prepared = clk_system_is_prepared,
+};
+
+static struct clk * __init
+at91_clk_register_system(struct at91_pmc *pmc, const char *name,
+                        const char *parent_name, u8 id, int irq)
+{
+       struct clk_system *sys;
+       struct clk *clk = NULL;
+       struct clk_init_data init;
+       int ret;
+
+       if (!parent_name || id > SYSTEM_MAX_ID)
+               return ERR_PTR(-EINVAL);
+
+       sys = kzalloc(sizeof(*sys), GFP_KERNEL);
+       if (!sys)
+               return ERR_PTR(-ENOMEM);
+
+       init.name = name;
+       init.ops = &system_ops;
+       init.parent_names = &parent_name;
+       init.num_parents = 1;
+       init.flags = CLK_SET_RATE_PARENT;
+
+       sys->id = id;
+       sys->hw.init = &init;
+       sys->pmc = pmc;
+       sys->irq = irq;
+       if (irq) {
+               init_waitqueue_head(&sys->wait);
+               irq_set_status_flags(sys->irq, IRQ_NOAUTOEN);
+               ret = request_irq(sys->irq, clk_system_irq_handler,
+                               IRQF_TRIGGER_HIGH, name, sys);
+               if (ret)
+                       return ERR_PTR(ret);
+       }
+
+       clk = clk_register(NULL, &sys->hw);
+       if (IS_ERR(clk))
+               kfree(sys);
+
+       return clk;
+}
+
+static void __init
+of_at91_clk_sys_setup(struct device_node *np, struct at91_pmc *pmc)
+{
+       int num;
+       int irq = 0;
+       u32 id;
+       struct clk *clk;
+       const char *name;
+       struct device_node *sysclknp;
+       const char *parent_name;
+
+       num = of_get_child_count(np);
+       if (num > (SYSTEM_MAX_ID + 1))
+               return;
+
+       for_each_child_of_node(np, sysclknp) {
+               if (of_property_read_u32(sysclknp, "reg", &id))
+                       continue;
+
+               if (of_property_read_string(np, "clock-output-names", &name))
+                       name = sysclknp->name;
+
+               if (is_pck(id))
+                       irq = irq_of_parse_and_map(sysclknp, 0);
+
+               parent_name = of_clk_get_parent_name(sysclknp, 0);
+
+               clk = at91_clk_register_system(pmc, name, parent_name, id, irq);
+               if (IS_ERR(clk))
+                       continue;
+
+               of_clk_add_provider(sysclknp, of_clk_src_simple_get, clk);
+       }
+}
+
+void __init of_at91rm9200_clk_sys_setup(struct device_node *np,
+                                       struct at91_pmc *pmc)
+{
+       of_at91_clk_sys_setup(np, pmc);
+}