clk: at91: add PMC utmi clock

This adds new at91 utmi clock implementation using common clk framework.

This clock is a pll with a fixed factor (x40).
It is used as a source for usb clock.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

5 files changed, 179 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 85b53a441459..6ad37daca971 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -1,5 +1,8 @@
 if ARCH_AT91
 
+config HAVE_AT91_UTMI
+        bool
+
 config HAVE_AT91_DBGU0
         bool
 
@@ -78,6 +81,7 @@ config SOC_SAMA5D3
         select HAVE_FB_ATMEL
         select HAVE_AT91_DBGU1
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_UTMI
         help
           Select this if you are using one of Atmel's SAMA5D3 family SoC.
           This support covers SAMA5D31, SAMA5D33, SAMA5D34, SAMA5D35.
@@ -124,6 +128,7 @@ config SOC_AT91SAM9RL
         select HAVE_FB_ATMEL
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_UTMI
 
 config SOC_AT91SAM9G45
         bool "AT91SAM9G45 or AT91SAM9M10 families"
@@ -131,6 +136,7 @@ config SOC_AT91SAM9G45
         select HAVE_FB_ATMEL
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_UTMI
         help
           Select this if you are using one of Atmel's AT91SAM9G45 family SoC.
           This support covers AT91SAM9G45, AT91SAM9G46, AT91SAM9M10 and AT91SAM9M11.
@@ -141,6 +147,7 @@ config SOC_AT91SAM9X5
         select HAVE_FB_ATMEL
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_UTMI
         help
           Select this if you are using one of Atmel's AT91SAM9x5 family SoC.
           This means that your SAM9 name finishes with a '5' (except if it is
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index 3873b621768f..a82488323ea4 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -7,3 +7,4 @@ obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o
 obj-y += clk-system.o clk-peripheral.o
 
 obj-$(CONFIG_AT91_PROGRAMMABLE_CLOCKS)  += clk-programmable.o
+obj-$(CONFIG_HAVE_AT91_UTMI)            += clk-utmi.o
diff --git a/drivers/clk/at91/clk-utmi.c b/drivers/clk/at91/clk-utmi.c
new file mode 100644
index 000000000000..ae3263bc1476
--- /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;
+}