clk: at91: add PMC usb clock

This patch adds new at91 usb clock implementation using common clk framework.
This clock is used to clock usb ports (ohci, ehci and udc).

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, 434 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 6ad37daca971..b76dc4c62af9 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -3,6 +3,9 @@ if ARCH_AT91
 config HAVE_AT91_UTMI
         bool
 
+config HAVE_AT91_USB_CLK
+        bool
+
 config HAVE_AT91_DBGU0
         bool
 
@@ -82,6 +85,7 @@ config SOC_SAMA5D3
         select HAVE_AT91_DBGU1
         select AT91_USE_OLD_CLK
         select HAVE_AT91_UTMI
+        select HAVE_AT91_USB_CLK
         help
           Select this if you are using one of Atmel's SAMA5D3 family SoC.
           This support covers SAMA5D31, SAMA5D33, SAMA5D34, SAMA5D35.
@@ -96,12 +100,14 @@ config SOC_AT91RM9200
         select MULTI_IRQ_HANDLER
         select SPARSE_IRQ
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_USB_CLK
 
 config SOC_AT91SAM9260
         bool "AT91SAM9260, AT91SAM9XE or AT91SAM9G20"
         select HAVE_AT91_DBGU0
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_USB_CLK
         help
           Select this if you are using one of Atmel's AT91SAM9260, AT91SAM9XE
           or AT91SAM9G20 SoC.
@@ -112,6 +118,7 @@ config SOC_AT91SAM9261
         select HAVE_FB_ATMEL
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_USB_CLK
         help
           Select this if you are using one of Atmel's AT91SAM9261 or AT91SAM9G10 SoC.
 
@@ -121,6 +128,7 @@ config SOC_AT91SAM9263
         select HAVE_FB_ATMEL
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_USB_CLK
 
 config SOC_AT91SAM9RL
         bool "AT91SAM9RL"
@@ -137,6 +145,7 @@ config SOC_AT91SAM9G45
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
         select HAVE_AT91_UTMI
+        select HAVE_AT91_USB_CLK
         help
           Select this if you are using one of Atmel's AT91SAM9G45 family SoC.
           This support covers AT91SAM9G45, AT91SAM9G46, AT91SAM9M10 and AT91SAM9M11.
@@ -148,6 +157,7 @@ config SOC_AT91SAM9X5
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
         select HAVE_AT91_UTMI
+        select HAVE_AT91_USB_CLK
         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
@@ -161,6 +171,7 @@ config SOC_AT91SAM9N12
         select HAVE_FB_ATMEL
         select SOC_AT91SAM9
         select AT91_USE_OLD_CLK
+        select HAVE_AT91_USB_CLK
         help
           Select this if you are using Atmel's AT91SAM9N12 SoC.
 
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index a82488323ea4..61db058be0c0 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -8,3 +8,4 @@ obj-y += clk-system.o clk-peripheral.o
 
 obj-$(CONFIG_AT91_PROGRAMMABLE_CLOCKS)  += clk-programmable.o
 obj-$(CONFIG_HAVE_AT91_UTMI)            += clk-utmi.o
+obj-$(CONFIG_HAVE_AT91_USB_CLK)         += clk-usb.o
diff --git a/drivers/clk/at91/clk-usb.c b/drivers/clk/at91/clk-usb.c
new file mode 100644
index 000000000000..7d1d26a4bd04
--- /dev/null
+++ b/drivers/clk/at91/clk-usb.c
@@ -0,0 +1,398 @@
+/*
+ *  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 "pmc.h"
+
+#define USB_SOURCE_MAX          2
+
+#define SAM9X5_USB_DIV_SHIFT    8
+#define SAM9X5_USB_MAX_DIV      0xf
+
+#define RM9200_USB_DIV_SHIFT    28
+#define RM9200_USB_DIV_TAB_SIZE 4
+
+struct at91sam9x5_clk_usb {
+        struct clk_hw hw;
+        struct at91_pmc *pmc;
+};
+
+#define to_at91sam9x5_clk_usb(hw) \
+        container_of(hw, struct at91sam9x5_clk_usb, hw)
+
+struct at91rm9200_clk_usb {
+        struct clk_hw hw;
+        struct at91_pmc *pmc;
+        u32 divisors[4];
+};
+
+#define to_at91rm9200_clk_usb(hw) \
+        container_of(hw, struct at91rm9200_clk_usb, hw)
+
+static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
+                                                    unsigned long parent_rate)
+{
+        u32 tmp;
+        u8 usbdiv;
+        struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
+        struct at91_pmc *pmc = usb->pmc;
+
+        tmp = pmc_read(pmc, AT91_PMC_USB);
+        usbdiv = (tmp & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
+        return parent_rate / (usbdiv + 1);
+}
+
+static long at91sam9x5_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
+                                          unsigned long *parent_rate)
+{
+        unsigned long div;
+        unsigned long bestrate;
+        unsigned long tmp;
+
+        if (rate >= *parent_rate)
+                return *parent_rate;
+
+        div = *parent_rate / rate;
+        if (div >= SAM9X5_USB_MAX_DIV)
+                return *parent_rate / (SAM9X5_USB_MAX_DIV + 1);
+
+        bestrate = *parent_rate / div;
+        tmp = *parent_rate / (div + 1);
+        if (bestrate - rate > rate - tmp)
+                bestrate = tmp;
+
+        return bestrate;
+}
+
+static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
+{
+        u32 tmp;
+        struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
+        struct at91_pmc *pmc = usb->pmc;
+