MIPS: lantiq: implement support for clkdev api

This patch unifies all clock generation and gating code into one file.
All drivers will now be able to request their clocks via their device.
This patch also adds support for the clockout feature, which allows
clock generation on external pins.

Support for COMMON_CLK will be provided in the next series.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3804/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 151 insertions, 0 deletions

diff --git a/arch/mips/lantiq/xway/clk.c b/arch/mips/lantiq/xway/clk.c
new file mode 100644
index 000000000000..9aa17f79a742
--- /dev/null
+++ b/arch/mips/lantiq/xway/clk.c
@@ -0,0 +1,151 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/io.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+
+#include <asm/time.h>
+#include <asm/irq.h>
+#include <asm/div64.h>
+
+#include <lantiq_soc.h>
+
+#include "../clk.h"
+
+static unsigned int ram_clocks[] = {
+	CLOCK_167M, CLOCK_133M, CLOCK_111M, CLOCK_83M };
+#define DDR_HZ ram_clocks[ltq_cgu_r32(CGU_SYS) & 0x3]
+
+/* legacy xway clock */
+#define CGU_SYS			0x10
+
+/* vr9 clock */
+#define CGU_SYS_VR9		0x0c
+#define CGU_IF_CLK_VR9		0x24
+
+unsigned long ltq_danube_fpi_hz(void)
+{
+	unsigned long ddr_clock = DDR_HZ;
+
+	if (ltq_cgu_r32(CGU_SYS) & 0x40)
+		return ddr_clock >> 1;
+	return ddr_clock;
+}
+
+unsigned long ltq_danube_cpu_hz(void)
+{
+	switch (ltq_cgu_r32(CGU_SYS) & 0xc) {
+	case 0:
+		return CLOCK_333M;
+	case 4:
+		return DDR_HZ;
+	case 8:
+		return DDR_HZ << 1;
+	default:
+		return DDR_HZ >> 1;
+	}
+}
+
+unsigned long ltq_ar9_sys_hz(void)
+{
+	if (((ltq_cgu_r32(CGU_SYS) >> 3) & 0x3) == 0x2)
+		return CLOCK_393M;
+	return CLOCK_333M;
+}
+
+unsigned long ltq_ar9_fpi_hz(void)
+{
+	unsigned long sys = ltq_ar9_sys_hz();
+
+	if (ltq_cgu_r32(CGU_SYS) & BIT(0))
+		return sys;
+	return sys >> 1;
+}
+
+unsigned long ltq_ar9_cpu_hz(void)
+{
+	if (ltq_cgu_r32(CGU_SYS) & BIT(2))
+		return ltq_ar9_fpi_hz();
+	else
+		return ltq_ar9_sys_hz();
+}
+
+unsigned long ltq_vr9_cpu_hz(void)
+{
+	unsigned int cpu_sel;
+	unsigned long clk;
+
+	cpu_sel = (ltq_cgu_r32(CGU_SYS_VR9) >> 4) & 0xf;
+
+	switch (cpu_sel) {
+	case 0:
+		clk = CLOCK_600M;
+		break;
+	case 1:
+		clk = CLOCK_500M;
+		break;
+	case 2:
+		clk = CLOCK_393M;
+		break;
+	case 3:
+		clk = CLOCK_333M;
+		break;
+	case 5:
+	case 6:
+		clk = CLOCK_196_608M;
+		break;
+	case 7:
+		clk = CLOCK_167M;
+		break;
+	case 4:
+	case 8:
+	case 9:
+		clk = CLOCK_125M;
+		break;
+	default:
+		clk = 0;
+		break;
+	}
+
+	return clk;
+}
+
+unsigned long ltq_vr9_fpi_hz(void)
+{
+	unsigned int ocp_sel, cpu_clk;
+	unsigned long clk;
+
+	cpu_clk = ltq_vr9_cpu_hz();
+	ocp_sel = ltq_cgu_r32(CGU_SYS_VR9) & 0x3;
+
+	switch (ocp_sel) {
+	case 0:
+		/* OCP ratio 1 */
+		clk = cpu_clk;
+		break;
+	case 2:
+		/* OCP ratio 2 */
+		clk = cpu_clk / 2;
+		break;
+	case 3:
+		/* OCP ratio 2.5 */
+		clk = (cpu_clk * 2) / 5;
+		break;
+	case 4:
+		/* OCP ratio 3 */
+		clk = cpu_clk / 3;
+		break;
+	default:
+		clk = 0;
+		break;
+	}
+
+	return clk;
+}