MIPS: Add support for Texas Instruments AR7 System-on-a-Chip

This patch adds support for the Texas Instruments AR7 System-on-a-Chip.
It supports the TNETD7100, 7200 and 7300 versions of the SoC.

Signed-off-by: Matteo Croce <matteo@openwrt.org>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Eugene Konev <ejka@openwrt.org>
Signed-off-by: Nicolas Thill <nico@openwrt.org>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 440 insertions, 0 deletions

diff --git a/arch/mips/ar7/clock.c b/arch/mips/ar7/clock.c
new file mode 100644
index 000000000000..27dc6663f2fa
--- /dev/null
+++ b/arch/mips/ar7/clock.c
@@ -0,0 +1,440 @@
+/*
+ * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/gcd.h>
+#include <linux/io.h>
+
+#include <asm/addrspace.h>
+#include <asm/mach-ar7/ar7.h>
+
+#define BOOT_PLL_SOURCE_MASK	0x3
+#define CPU_PLL_SOURCE_SHIFT	16
+#define BUS_PLL_SOURCE_SHIFT	14
+#define USB_PLL_SOURCE_SHIFT	18
+#define DSP_PLL_SOURCE_SHIFT	22
+#define BOOT_PLL_SOURCE_AFE	0
+#define BOOT_PLL_SOURCE_BUS	0
+#define BOOT_PLL_SOURCE_REF	1
+#define BOOT_PLL_SOURCE_XTAL	2
+#define BOOT_PLL_SOURCE_CPU	3
+#define BOOT_PLL_BYPASS		0x00000020
+#define BOOT_PLL_ASYNC_MODE	0x02000000
+#define BOOT_PLL_2TO1_MODE	0x00008000
+
+#define TNETD7200_CLOCK_ID_CPU	0
+#define TNETD7200_CLOCK_ID_DSP	1
+#define TNETD7200_CLOCK_ID_USB	2
+
+#define TNETD7200_DEF_CPU_CLK	211000000
+#define TNETD7200_DEF_DSP_CLK	125000000
+#define TNETD7200_DEF_USB_CLK	48000000
+
+struct tnetd7300_clock {
+	u32 ctrl;
+#define PREDIV_MASK	0x001f0000
+#define PREDIV_SHIFT	16
+#define POSTDIV_MASK	0x0000001f
+	u32 unused1[3];
+	u32 pll;
+#define MUL_MASK	0x0000f000
+#define MUL_SHIFT	12
+#define PLL_MODE_MASK	0x00000001
+#define PLL_NDIV	0x00000800
+#define PLL_DIV		0x00000002
+#define PLL_STATUS	0x00000001
+	u32 unused2[3];
+};
+
+struct tnetd7300_clocks {
+	struct tnetd7300_clock bus;
+	struct tnetd7300_clock cpu;
+	struct tnetd7300_clock usb;
+	struct tnetd7300_clock dsp;
+};
+
+struct tnetd7200_clock {
+	u32 ctrl;
+	u32 unused1[3];
+#define DIVISOR_ENABLE_MASK 0x00008000
+	u32 mul;
+	u32 prediv;
+	u32 postdiv;
+	u32 postdiv2;
+	u32 unused2[6];
+	u32 cmd;
+	u32 status;
+	u32 cmden;
+	u32 padding[15];
+};
+
+struct tnetd7200_clocks {
+	struct tnetd7200_clock cpu;
+	struct tnetd7200_clock dsp;
+	struct tnetd7200_clock usb;
+};
+
+int ar7_cpu_clock = 150000000;
+EXPORT_SYMBOL(ar7_cpu_clock);
+int ar7_bus_clock = 125000000;
+EXPORT_SYMBOL(ar7_bus_clock);
+int ar7_dsp_clock;
+EXPORT_SYMBOL(ar7_dsp_clock);
+
+static void approximate(int base, int target, int *prediv,
+			int *postdiv, int *mul)
+{
+	int i, j, k, freq, res = target;
+	for (i = 1; i <= 16; i++)
+		for (j = 1; j <= 32; j++)
+			for (k = 1; k <= 32; k++) {
+				freq = abs(base / j * i / k - target);
+				if (freq < res) {
+					res = freq;
+					*mul = i;
+					*prediv = j;
+					*postdiv = k;
+				}
+			}
+}
+
+static void calculate(int base, int target, int *prediv, int *postdiv,
+	int *mul)
+{
+	int tmp_gcd, tmp_base, tmp_freq;
+
+	for (*prediv = 1; *prediv <= 32; (*prediv)++) {
+		tmp_base = base / *prediv;
+		tmp_gcd = gcd(target, tmp_base);
+		*mul = target / tmp_gcd;
+		*postdiv = tmp_base / tmp_gcd;
+		if ((*mul < 1) || (*mul >= 16))
+			continue;
+		if ((*postdiv > 0) & (*postdiv <= 32))
+			break;
+	}
+
+	if (base / *prediv * *mul / *postdiv != target) {
+		approximate(base, target, prediv, postdiv, mul);
+		tmp_freq = base / *prediv * *mul / *postdiv;
+		printk(KERN_WARNING
+		       "Adjusted requested frequency %d to %d\n",
+		       target, tmp_freq);
+	}
+
+	printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
+	       *prediv, *postdiv, *mul);
+}
+
+static int tnetd7300_dsp_clock(void)
+{
+	u32 didr1, didr2;
+	u8 rev = ar7_chip_rev();
+	didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
+	didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
+	if (didr2 & (1 << 23))
+		return 0;
+	if ((rev >= 0x23) && (rev != 0x57))
+		return 250000000;
+	if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
+	    > 4208000)
+		return 250000000;
+	return 0;
+}
+
+static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
+	u32 *bootcr, u32 bus_clock)
+{
+	int product;
+	int base_clock = AR7_REF_CLOCK;
+	u32 ctrl = readl(&clock->ctrl);
+	u32 pll = readl(&clock->pll);
+	int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
+	int postdiv = (ctrl & POSTDIV_MASK) + 1;
+	int divisor = prediv * postdiv;
+	int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
+
+	switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
+	case BOOT_PLL_SOURCE_BUS:
+		base_clock = bus_clock;
+		break;
+	case BOOT_PLL_SOURCE_REF:
+		base_clock = AR7_REF_CLOCK;
+		break;
+	case BOOT_PLL_SOURCE_XTAL:
+		base_clock = AR7_XTAL_CLOCK;
+		break;
+	case BOOT_PLL_SOURCE_CPU:
+		base_clock = ar7_cpu_clock;
+		break;
+	}
+
+	if (*bootcr & BOOT_PLL_BYPASS)
+		return base_clock / divisor;
+
+	if ((pll & PLL_MODE_MASK) == 0)
+		return (base_clock >> (mul / 16 + 1)) / divisor;
+
+	if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
+		product = (mul & 1) ?
+			(base_clock * mul) >> 1 :
+			(base_clock * (mul - 1)) >> 2;
+		return product / divisor;
+	}
+
+	if (mul == 16)
+		return base_clock / divisor;
+
+	return base_clock * mul / divisor;
+}
+
+static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
+	u32 *bootcr, u32 frequency)
+{
+	int prediv, postdiv, mul;
+	int base_clock = ar7_bus_clock;
+
+	switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
+	case BOOT_PLL_SOURCE_BUS:
+		base_clock = ar7_bus_clock;
+		break;
+	case BOOT_PLL_SOURCE_REF:
+		base_clock = AR7_REF_CLOCK;
+		break;
+	case BOOT_PLL_SOURCE_XTAL:
+		base_clock = AR7_XTAL_CLOCK;
+		break;
+	case BOOT_PLL_SOURCE_CPU:
+		base_clock = ar7_cpu_clock;
+		break;
+	}
+
+	calculate(base_clock, frequency, &prediv, &postdiv, &mul);
+
+	writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
+	msleep(1);
+	writel(4, &clock->pll);
+	while (readl(&clock->pll) & PLL_STATUS)
+		;
+	writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
+	msleep(75);
+}
+
+static void __init tnetd7300_init_clocks(void)
+{
+	u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
+	struct tnetd7300_clocks *clocks =
+					ioremap_nocache(UR8_REGS_CLOCKS,
+					sizeof(struct tnetd7300_clocks));
+
+	ar7_bus_clock = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
+		&clocks->bus, bootcr, AR7_AFE_CLOCK);
+
+	if (*bootcr & BOOT_PLL_ASYNC_MODE)
+		ar7_cpu_clock = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
+			&clocks->cpu, bootcr, AR7_AFE_CLOCK);
+	else
+		ar7_cpu_clock = ar7_bus_clock;
+
+	if (ar7_dsp_clock == 250000000)
+		tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
+			bootcr, ar7_dsp_clock);
+
+	iounmap(clocks);
+	iounmap(bootcr);
+}
+
+static int tnetd7200_get_clock(int base, struct tnetd7200_clock *clock,
+	u32 *bootcr, u32 bus_clock)
+{
+	int divisor = ((readl(&clock->prediv) & 0x1f) + 1) *
+		((readl(&clock->postdiv) & 0x1f) + 1);
+
+	if (*bootcr & BOOT_PLL_BYPASS)
+		return base / divisor;
+
+	return base * ((readl(&clock->mul) & 0xf) + 1) / divisor;
+}
+
+
+static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
+	int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
+{
+	printk(KERN_INFO
+		"Clocks: base = %d, frequency = %u, prediv = %d, "
+		"postdiv = %d, postdiv2 = %d, mul = %d\n",
+		base, frequency, prediv, postdiv, postdiv2, mul);
+
+	writel(0, &clock->ctrl);
+	writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
+	writel((mul - 1) & 0xF, &clock->mul);
+
+	while (readl(&clock->status) & 0x1)
+		; /* nop */
+
+	writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
+
+	writel(readl(&clock->cmden) | 1, &clock->cmden);
+	writel(readl(&clock->cmd) | 1, &clock->cmd);
+
+	while (readl(&clock->status) & 0x1)
+		; /* nop */
+
+	writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
+
+	writel(readl(&clock->cmden) | 1, &clock->cmden);
+	writel(readl(&clock->cmd) | 1, &clock->cmd);
+
+	while (readl(&clock->status) & 0x1)
+		; /* nop */
+
+	writel(readl(&clock->ctrl) | 1, &clock->ctrl);
+}
+
+static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
+{
+	if (*bootcr & BOOT_PLL_ASYNC_MODE)
+		/* Async */
+		switch (clock_id) {
+		case TNETD7200_CLOCK_ID_DSP:
+			return AR7_REF_CLOCK;
+		default:
+			return AR7_AFE_CLOCK;
+		}
+	else
+		/* Sync */
+		if (*bootcr & BOOT_PLL_2TO1_MODE)
+			/* 2:1 */
+			switch (clock_id) {
+			case TNETD7200_CLOCK_ID_DSP:
+				return AR7_REF_CLOCK;
+			default:
+				return AR7_AFE_CLOCK;
+			}
+		else
+			/* 1:1 */
+			return AR7_REF_CLOCK;
+}
+
+
+static void __init tnetd7200_init_clocks(void)
+{
+	u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
+	struct tnetd7200_clocks *clocks =
+					ioremap_nocache(AR7_REGS_CLOCKS,
+					sizeof(struct tnetd7200_clocks));
+	int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
+	int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
+	int usb_base, usb_mul, usb_prediv, usb_postdiv;
+
+	cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
+	dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
+
+	if (*bootcr & BOOT_PLL_ASYNC_MODE) {
+		printk(KERN_INFO "Clocks: Async mode\n");
+
+		printk(KERN_INFO "Clocks: Setting DSP clock\n");
+		calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
+			&dsp_prediv, &dsp_postdiv, &dsp_mul);
+		ar7_bus_clock =
+			((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
+		tnetd7200_set_clock(dsp_base, &clocks->dsp,
+			dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
+			ar7_bus_clock);
+
+		printk(KERN_INFO "Clocks: Setting CPU clock\n");
+		calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
+			&cpu_postdiv, &cpu_mul);
+		ar7_cpu_clock =
+			((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
+		tnetd7200_set_clock(cpu_base, &clocks->cpu,
+			cpu_prediv, cpu_postdiv, -1, cpu_mul,
+			ar7_cpu_clock);
+
+	} else
+		if (*bootcr & BOOT_PLL_2TO1_MODE) {
+			printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
+
+			printk(KERN_INFO "Clocks: Setting CPU clock\n");
+			calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
+				&cpu_postdiv, &cpu_mul);
+			ar7_cpu_clock = ((cpu_base / cpu_prediv) * cpu_mul)
+								/ cpu_postdiv;
+			tnetd7200_set_clock(cpu_base, &clocks->cpu,
+				cpu_prediv, cpu_postdiv, -1, cpu_mul,
+				ar7_cpu_clock);
+
+			printk(KERN_INFO "Clocks: Setting DSP clock\n");
+			calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
+				&dsp_postdiv, &dsp_mul);
+			ar7_bus_clock = ar7_cpu_clock / 2;
+			tnetd7200_set_clock(dsp_base, &clocks->dsp,
+				dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
+				dsp_mul * 2, ar7_bus_clock);
+		} else {
+			printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
+
+			printk(KERN_INFO "Clocks: Setting DSP clock\n");
+			calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
+				&dsp_postdiv, &dsp_mul);
+			ar7_bus_clock = ((dsp_base / dsp_prediv) * dsp_mul)
+								/ dsp_postdiv;
+			tnetd7200_set_clock(dsp_base, &clocks->dsp,
+				dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
+				dsp_mul * 2, ar7_bus_clock);
+
+			ar7_cpu_clock = ar7_bus_clock;
+		}
+
+	printk(KERN_INFO "Clocks: Setting USB clock\n");
+	usb_base = ar7_bus_clock;
+	calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
+		&usb_postdiv, &usb_mul);
+	tnetd7200_set_clock(usb_base, &clocks->usb,
+		usb_prediv, usb_postdiv, -1, usb_mul,
+		TNETD7200_DEF_USB_CLK);
+
+	ar7_dsp_clock = ar7_cpu_clock;
+
+	iounmap(clocks);
+	iounmap(bootcr);
+}
+
+int __init ar7_init_clocks(void)
+{
+	switch (ar7_chip_id()) {
+	case AR7_CHIP_7100:
+	case AR7_CHIP_7200:
+		tnetd7200_init_clocks();
+		break;
+	case AR7_CHIP_7300:
+		ar7_dsp_clock = tnetd7300_dsp_clock();
+		tnetd7300_init_clocks();
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+arch_initcall(ar7_init_clocks);