4 files changed, 196 insertions, 0 deletions

diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index 1d4fb214bbc4..44105bd44aa1 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-y += pmc.o
+obj-y += clk-main.o
diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c
new file mode 100644
index 000000000000..8e9e8cc0412d
--- /dev/null
+++ b/drivers/clk/at91/clk-main.c
@@ -0,0 +1,187 @@
+/*
+ *  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/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#include "pmc.h"
+
+#define SLOW_CLOCK_FREQ         32768
+#define MAINF_DIV               16
+#define MAINFRDY_TIMEOUT        (((MAINF_DIV + 1) * USEC_PER_SEC) / \
+                                 SLOW_CLOCK_FREQ)
+#define MAINF_LOOP_MIN_WAIT     (USEC_PER_SEC / SLOW_CLOCK_FREQ)
+#define MAINF_LOOP_MAX_WAIT     MAINFRDY_TIMEOUT
+
+struct clk_main {
+        struct clk_hw hw;
+        struct at91_pmc *pmc;
+        unsigned long rate;
+        unsigned int irq;
+        wait_queue_head_t wait;
+};
+
+#define to_clk_main(hw) container_of(hw, struct clk_main, hw)
+
+static irqreturn_t clk_main_irq_handler(int irq, void *dev_id)
+{
+        struct clk_main *clkmain = (struct clk_main *)dev_id;
+
+        wake_up(&clkmain->wait);
+        disable_irq_nosync(clkmain->irq);
+
+        return IRQ_HANDLED;
+}
+
+static int clk_main_prepare(struct clk_hw *hw)
+{
+        struct clk_main *clkmain = to_clk_main(hw);
+        struct at91_pmc *pmc = clkmain->pmc;
+        unsigned long halt_time, timeout;
+        u32 tmp;
+
+        while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS)) {
+                enable_irq(clkmain->irq);
+                wait_event(clkmain->wait,
+                           pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS);
+        }
+
+        if (clkmain->rate)
+                return 0;
+
+        timeout = jiffies + usecs_to_jiffies(MAINFRDY_TIMEOUT);
+        do {
+                halt_time = jiffies;
+                tmp = pmc_read(pmc, AT91_CKGR_MCFR);
+                if (tmp & AT91_PMC_MAINRDY)
+                        return 0;
+                usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT);
+        } while (time_before(halt_time, timeout));
+
+        return 0;
+}
+
+static int clk_main_is_prepared(struct clk_hw *hw)
+{
+        struct clk_main *clkmain = to_clk_main(hw);
+
+        return !!(pmc_read(clkmain->pmc, AT91_PMC_SR) & AT91_PMC_MOSCS);
+}
+
+static unsigned long clk_main_recalc_rate(struct clk_hw *hw,
+                                          unsigned long parent_rate)
+{
+        u32 tmp;
+        struct clk_main *clkmain = to_clk_main(hw);
+        struct at91_pmc *pmc = clkmain->pmc;
+
+        if (clkmain->rate)
+                return clkmain->rate;
+
+        tmp = pmc_read(pmc, AT91_CKGR_MCFR) & AT91_PMC_MAINF;
+        clkmain->rate = (tmp * parent_rate) / MAINF_DIV;
+
+        return clkmain->rate;
+}
+
+static const struct clk_ops main_ops = {
+        .prepare = clk_main_prepare,
+        .is_prepared = clk_main_is_prepared,
+        .recalc_rate = clk_main_recalc_rate,
+};
+
+static struct clk * __init
+at91_clk_register_main(struct at91_pmc *pmc,
+                       unsigned int irq,
+                       const char *name,
+                       const char *parent_name,
+                       unsigned long rate)
+{
+        int ret;
+        struct clk_main *clkmain;
+        struct clk *clk = NULL;
+        struct clk_init_data init;
+
+        if (!pmc || !irq || !name)
+                return ERR_PTR(-EINVAL);
+
+        if (!rate && !parent_name)
+                return ERR_PTR(-EINVAL);
+
+        clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
+        if (!clkmain)
+                return ERR_PTR(-ENOMEM);
+
+        init.name = name;
+        init.ops = &main_ops;
+        init.parent_names = parent_name ? &parent_name : NULL;
+        init.num_parents = parent_name ? 1 : 0;
+        init.flags = parent_name ? 0 : CLK_IS_ROOT;
+
+        clkmain->hw.init = &init;
+        clkmain->rate = rate;
+        clkmain->pmc = pmc;
+        clkmain->irq = irq;
+        init_waitqueue_head(&clkmain->wait);
+        irq_set_status_flags(clkmain->irq, IRQ_NOAUTOEN);
+        ret = request_irq(clkmain->irq, clk_main_irq_handler,
+                          IRQF_TRIGGER_HIGH, "clk-main", clkmain);
+        if (ret)
+                return ERR_PTR(ret);
+
+        clk = clk_register(NULL, &clkmain->hw);
+        if (IS_ERR(clk)) {
+                free_irq(clkmain->irq, clkmain);
+                kfree(clkmain);
+        }
+
+        return clk;
+}
+
+
+
+static void __init
+of_at91_clk_main_setup(struct device_node *np, struct at91_pmc *pmc)
+{
+        struct clk *clk;
+        unsigned int irq;
+        const char *parent_name;
+        const char *name = np->name;
+        u32 rate = 0;
+
+        parent_name = of_clk_get_parent_name(np, 0);
+        of_property_read_string(np, "clock-output-names", &name);
+        of_property_read_u32(np, "clock-frequency", &rate);
+        irq = irq_of_parse_and_map(np, 0);
+        if (!irq)
+                return;
+
+        clk = at91_clk_register_main(pmc, irq, name, parent_name, rate);
+        if (IS_ERR(clk))
+                return;
+
+        of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+void __init of_at91rm9200_clk_main_setup(struct device_node *np,
+                                         struct at91_pmc *pmc)
+{
+        of_at91_clk_main_setup(np, pmc);
+}
diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index 69c116a6ba4f..3d35b7313868 100644
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -229,6 +229,11 @@ out_free_pmc:
 }
 
 static const struct of_device_id pmc_clk_ids[] __initdata = {
+        /* Main clock */
+        {
+                .compatible = "atmel,at91rm9200-clk-main",
+                .data = of_at91rm9200_clk_main_setup,
+        },
         { /*sentinel*/ }
 };
 
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index d92b946cdc9e..729aa46c7289 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -58,4 +58,7 @@ static inline void pmc_write(struct at91_pmc *pmc, int offset, u32 value)
 int of_at91_get_clk_range(struct device_node *np, const char *propname,
                           struct clk_range *range);
 
+extern void __init of_at91rm9200_clk_main_setup(struct device_node *np,
+                                                struct at91_pmc *pmc);
+
 #endif /* __PMC_H_ */