clk: add pxa clocks infrastructure

Add a the common code used by all PXA variants.

This is the first step in the transition from architecture defined
clocks (in arch/arm/mach-pxa) towards clock framework. The goal is to
have the same features (and not all the features) of the existing
clocks, and enable the transition of PXA to device-tree.

All PXA rely on a "CKEN" type clock, which :
 - has a gate (bit in CKEN register)
 - is generated from a PLL, generally divided
 - has an alternate low power clock

Each variant will specialize the CKEN clock :
 - pxa25x have no low power clock
 - pxa27x in low power use always the 13 MHz ring oscillator
 - pxa3xx in low power have specific dividers for each clock

The device-tree provides a list of CLK_* (ex: CLK_USB or CLK_I2C) to get
a handle on the clock. While pxa-clock.h will describe all the clocks of
all the variants, each variant will only use a subset of it.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

include/dt-bindings/clock/pxa-clock.h

@@ -0,0 +1,77 @@
+/*
+ * Inspired by original work from pxa2xx-regs.h by Nicolas Pitre
+ * Copyright (C) 2014 Robert Jarzmik
+ *
+ * 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.
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_PXA2XX_H__
+#define __DT_BINDINGS_CLOCK_PXA2XX_H__
+
+#define CLK_NONE 0
+#define CLK_1WIRE 1
+#define CLK_AC97 2
+#define CLK_AC97CONF 3
+#define CLK_ASSP 4
+#define CLK_BOOT 5
+#define CLK_BTUART 6
+#define CLK_CAMERA 7
+#define CLK_CIR 8
+#define CLK_CORE 9
+#define CLK_DMC 10
+#define CLK_FFUART 11
+#define CLK_FICP 12
+#define CLK_GPIO 13
+#define CLK_HSIO2 14
+#define CLK_HWUART 15
+#define CLK_I2C 16
+#define CLK_I2S 17
+#define CLK_IM 18
+#define CLK_INC 19
+#define CLK_ISC 20
+#define CLK_KEYPAD 21
+#define CLK_LCD 22
+#define CLK_MEMC 23
+#define CLK_MEMSTK 24
+#define CLK_MINI_IM 25
+#define CLK_MINI_LCD 26
+#define CLK_MMC 27
+#define CLK_MMC1 28
+#define CLK_MMC2 29
+#define CLK_MMC3 30
+#define CLK_MSL 31
+#define CLK_MSL0 32
+#define CLK_MVED 33
+#define CLK_NAND 34
+#define CLK_NSSP 35
+#define CLK_OSTIMER 36
+#define CLK_PWM0 37
+#define CLK_PWM1 38
+#define CLK_PWM2 39
+#define CLK_PWM3 40
+#define CLK_PWRI2C 41
+#define CLK_PXA300_GCU 42
+#define CLK_PXA320_GCU 43
+#define CLK_SMC 44
+#define CLK_SSP 45
+#define CLK_SSP1 46
+#define CLK_SSP2 47
+#define CLK_SSP3 48
+#define CLK_SSP4 49
+#define CLK_STUART 50
+#define CLK_TOUCH 51
+#define CLK_TPM 52
+#define CLK_UDC 53
+#define CLK_USB 54
+#define CLK_USB2 55
+#define CLK_USBH 56
+#define CLK_USBHOST 57
+#define CLK_USIM 58
+#define CLK_USIM1 59
+#define CLK_USMI0 60
+#define CLK_MAX 61
+
+#endif