summaryrefslogtreecommitdiffstats
path: root/drivers/clk/at91/clk-utmi.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/at91/clk-utmi.c')
-rw-r--r--drivers/clk/at91/clk-utmi.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-utmi.c b/drivers/clk/at91/clk-utmi.c
new file mode 100644
index 00000000000..ae3263bc147
--- /dev/null
+++ b/drivers/clk/at91/clk-utmi.c
@@ -0,0 +1,159 @@
+/*
+ * 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/interrupt.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#include "pmc.h"
+
+#define UTMI_FIXED_MUL 40
+
+struct clk_utmi {
+ struct clk_hw hw;
+ struct at91_pmc *pmc;
+ unsigned int irq;
+ wait_queue_head_t wait;
+};
+
+#define to_clk_utmi(hw) container_of(hw, struct clk_utmi, hw)
+
+static irqreturn_t clk_utmi_irq_handler(int irq, void *dev_id)
+{
+ struct clk_utmi *utmi = (struct clk_utmi *)dev_id;
+
+ wake_up(&utmi->wait);
+ disable_irq_nosync(utmi->irq);
+
+ return IRQ_HANDLED;
+}
+
+static int clk_utmi_prepare(struct clk_hw *hw)
+{
+ struct clk_utmi *utmi = to_clk_utmi(hw);
+ struct at91_pmc *pmc = utmi->pmc;
+ u32 tmp = at91_pmc_read(AT91_CKGR_UCKR) | AT91_PMC_UPLLEN |
+ AT91_PMC_UPLLCOUNT | AT91_PMC_BIASEN;
+
+ pmc_write(pmc, AT91_CKGR_UCKR, tmp);
+
+ while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_LOCKU)) {
+ enable_irq(utmi->irq);
+ wait_event(utmi->wait,
+ pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_LOCKU);
+ }
+
+ return 0;
+}
+
+static int clk_utmi_is_prepared(struct clk_hw *hw)
+{
+ struct clk_utmi *utmi = to_clk_utmi(hw);
+ struct at91_pmc *pmc = utmi->pmc;
+
+ return !!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_LOCKU);
+}
+
+static void clk_utmi_unprepare(struct clk_hw *hw)
+{
+ struct clk_utmi *utmi = to_clk_utmi(hw);
+ struct at91_pmc *pmc = utmi->pmc;
+ u32 tmp = at91_pmc_read(AT91_CKGR_UCKR) & ~AT91_PMC_UPLLEN;
+
+ pmc_write(pmc, AT91_CKGR_UCKR, tmp);
+}
+
+static unsigned long clk_utmi_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ /* UTMI clk is a fixed clk multiplier */
+ return parent_rate * UTMI_FIXED_MUL;
+}
+
+static const struct clk_ops utmi_ops = {
+ .prepare = clk_utmi_prepare,
+ .unprepare = clk_utmi_unprepare,
+ .is_prepared = clk_utmi_is_prepared,
+ .recalc_rate = clk_utmi_recalc_rate,
+};
+
+static struct clk * __init
+at91_clk_register_utmi(struct at91_pmc *pmc, unsigned int irq,
+ const char *name, const char *parent_name)
+{
+ int ret;
+ struct clk_utmi *utmi;
+ struct clk *clk = NULL;
+ struct clk_init_data init;
+
+ utmi = kzalloc(sizeof(*utmi), GFP_KERNEL);
+ if (!utmi)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &utmi_ops;
+ init.parent_names = parent_name ? &parent_name : NULL;
+ init.num_parents = parent_name ? 1 : 0;
+ init.flags = CLK_SET_RATE_GATE;
+
+ utmi->hw.init = &init;
+ utmi->pmc = pmc;
+ utmi->irq = irq;
+ init_waitqueue_head(&utmi->wait);
+ irq_set_status_flags(utmi->irq, IRQ_NOAUTOEN);
+ ret = request_irq(utmi->irq, clk_utmi_irq_handler,
+ IRQF_TRIGGER_HIGH, "clk-utmi", utmi);
+ if (ret)
+ return ERR_PTR(ret);
+
+ clk = clk_register(NULL, &utmi->hw);
+ if (IS_ERR(clk))
+ kfree(utmi);
+
+ return clk;
+}
+
+static void __init
+of_at91_clk_utmi_setup(struct device_node *np, struct at91_pmc *pmc)
+{
+ unsigned int irq;
+ struct clk *clk;
+ const char *parent_name;
+ const char *name = np->name;
+
+ parent_name = of_clk_get_parent_name(np, 0);
+
+ of_property_read_string(np, "clock-output-names", &name);
+
+ irq = irq_of_parse_and_map(np, 0);
+ if (!irq)
+ return;
+
+ clk = at91_clk_register_utmi(pmc, irq, name, parent_name);
+ if (IS_ERR(clk))
+ return;
+
+ of_clk_add_provider(np, of_clk_src_simple_get, clk);
+ return;
+}
+
+void __init of_at91sam9x5_clk_utmi_setup(struct device_node *np,
+ struct at91_pmc *pmc)
+{
+ of_at91_clk_utmi_setup(np, pmc);
+}