linux/arch/arm/mach-ixp4xx/common.c

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/*
* arch/arm/mach-ixp4xx/common.c
*
* Generic code shared across all IXP4XX platforms
*
* Maintainer: Deepak Saxena <dsaxena@plexity.net>
*
* Copyright 2002 (c) Intel Corporation
* Copyright 2003-2004 (c) MontaVista, Software, Inc.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/serial.h>
#include <linux/tty.h>
#include <linux/platform_device.h>
#include <linux/serial_core.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/export.h>
#include <linux/cpu.h>
#include <linux/pci.h>
#include <linux/sched_clock.h>
#include <linux/bitops.h>
#include <linux/irqchip/irq-ixp4xx.h>
#include <linux/platform_data/timer-ixp4xx.h>
#include <mach/udc.h>
#include <mach/hardware.h>
#include <mach/io.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/exception.h>
#include <asm/irq.h>
#include <asm/system_misc.h>
#include <asm/mach/map.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#include "irqs.h"
#define IXP4XX_TIMER_FREQ 66666000
ARM: ixp4xx: fix timer latch calculation In commit f0402f9b4711 ("ARM: ixp4xx: stop using <mach/timex.h>") I didn't intend to implement a functional change, but as Olof noticed I failed---at least a bit. Before this commit the following was used to determine the latch value used: #define IXP4XX_TIMER_FREQ 66666000 #define CLOCK_TICK_RATE \ (((IXP4XX_TIMER_FREQ / HZ & ~IXP4XX_OST_RELOAD_MASK) + 1) * HZ) #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) The complicated calculation was done "b/c the timer register ignores the bottom 2 bits of the LATCH value." With HZ=100 CLOCK_TICK_RATE used to calculate to 66666100 and so LATCH to 666661. In ixp4xx_set_mode the term LATCH & ~IXP4XX_OST_RELOAD_MASK was used to write to the relevant register (with IXP4XX_OST_RELOAD_MASK being 3) and so effectively 666660 was used. In commit f0402f9b4711 I translated that to: #define IXP4XX_TIMER_FREQ 66666000 #define IXP4XX_LATCH DIV_ROUND_CLOSEST(IXP4XX_TIMER_FREQ, HZ) which results in the same register writes, but still doesn't bear in mind that the two least significant bits cannot be specified (which is relevant only when HZ or IXP4XX_TIMER_FREQ are changed). Instead of reverting back to the old approach use a more obvious and also more correct way to calculate LATCH. (Regarding the more correct claim: With IXP4XX_TIMER_FREQ == 66665999, the old code resulted in LATCH = 666657 corresponding to a cycle time of 0.009999940149400597 seconds (error: -6.0e-8 s) while the new approach results in LATCH = 666660 and so a cycle time of 0.010000000150001503 seconds (error: 1.5e-10 s).) Fixes: f0402f9b4711 ("ARM: ixp4xx: stop using <mach/timex.h>") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2014-02-03 18:31:19 +08:00
/*************************************************************************
* IXP4xx chipset I/O mapping
*************************************************************************/
static struct map_desc ixp4xx_io_desc[] __initdata = {
{ /* UART, Interrupt ctrl, GPIO, timers, NPEs, MACs, USB .... */
.virtual = (unsigned long)IXP4XX_PERIPHERAL_BASE_VIRT,
.pfn = __phys_to_pfn(IXP4XX_PERIPHERAL_BASE_PHYS),
.length = IXP4XX_PERIPHERAL_REGION_SIZE,
.type = MT_DEVICE
}, { /* Expansion Bus Config Registers */
.virtual = (unsigned long)IXP4XX_EXP_CFG_BASE_VIRT,
.pfn = __phys_to_pfn(IXP4XX_EXP_CFG_BASE_PHYS),
.length = IXP4XX_EXP_CFG_REGION_SIZE,
.type = MT_DEVICE
}, { /* PCI Registers */
.virtual = (unsigned long)IXP4XX_PCI_CFG_BASE_VIRT,
.pfn = __phys_to_pfn(IXP4XX_PCI_CFG_BASE_PHYS),
.length = IXP4XX_PCI_CFG_REGION_SIZE,
.type = MT_DEVICE
}, { /* Queue Manager */
.virtual = (unsigned long)IXP4XX_QMGR_BASE_VIRT,
.pfn = __phys_to_pfn(IXP4XX_QMGR_BASE_PHYS),
.length = IXP4XX_QMGR_REGION_SIZE,
.type = MT_DEVICE
},
};
void __init ixp4xx_map_io(void)
{
iotable_init(ixp4xx_io_desc, ARRAY_SIZE(ixp4xx_io_desc));
}
void __init ixp4xx_init_irq(void)
{
/*
* ixp4xx does not implement the XScale PWRMODE register
* so it must not call cpu_do_idle().
*/
cpu_idle_poll_ctrl(true);
ixp4xx_irq_init(IXP4XX_INTC_BASE_PHYS,
(cpu_is_ixp46x() || cpu_is_ixp43x()));
}
void __init ixp4xx_timer_init(void)
{
return ixp4xx_timer_setup(IXP4XX_TIMER_BASE_PHYS,
IRQ_IXP4XX_TIMER1,
IXP4XX_TIMER_FREQ);
}
static struct pxa2xx_udc_mach_info ixp4xx_udc_info;
void __init ixp4xx_set_udc_info(struct pxa2xx_udc_mach_info *info)
{
memcpy(&ixp4xx_udc_info, info, sizeof *info);
}
static struct resource ixp4xx_udc_resources[] = {
[0] = {
.start = 0xc800b000,
.end = 0xc800bfff,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = IRQ_IXP4XX_USB,
.end = IRQ_IXP4XX_USB,
.flags = IORESOURCE_IRQ,
},
};
static struct resource ixp4xx_gpio_resource[] = {
{
.start = IXP4XX_GPIO_BASE_PHYS,
.end = IXP4XX_GPIO_BASE_PHYS + 0xfff,
.flags = IORESOURCE_MEM,
},
};
static struct platform_device ixp4xx_gpio_device = {
.name = "ixp4xx-gpio",
.id = -1,
.dev = {
.coherent_dma_mask = DMA_BIT_MASK(32),
},
.resource = ixp4xx_gpio_resource,
.num_resources = ARRAY_SIZE(ixp4xx_gpio_resource),
};
/*
* USB device controller. The IXP4xx uses the same controller as PXA25X,
* so we just use the same device.
*/
static struct platform_device ixp4xx_udc_device = {
.name = "pxa25x-udc",
.id = -1,
.num_resources = 2,
.resource = ixp4xx_udc_resources,
.dev = {
.platform_data = &ixp4xx_udc_info,
},
};
static struct platform_device *ixp4xx_devices[] __initdata = {
&ixp4xx_gpio_device,
&ixp4xx_udc_device,
};
static struct resource ixp46x_i2c_resources[] = {
[0] = {
.start = 0xc8011000,
.end = 0xc801101c,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = IRQ_IXP4XX_I2C,
.end = IRQ_IXP4XX_I2C,
.flags = IORESOURCE_IRQ
}
};
/*
* I2C controller. The IXP46x uses the same block as the IOP3xx, so
* we just use the same device name.
*/
static struct platform_device ixp46x_i2c_controller = {
.name = "IOP3xx-I2C",
.id = 0,
.num_resources = 2,
.resource = ixp46x_i2c_resources
};
static struct platform_device *ixp46x_devices[] __initdata = {
&ixp46x_i2c_controller
};
unsigned long ixp4xx_exp_bus_size;
EXPORT_SYMBOL(ixp4xx_exp_bus_size);
void __init ixp4xx_sys_init(void)
{
ixp4xx_exp_bus_size = SZ_16M;
platform_add_devices(ixp4xx_devices, ARRAY_SIZE(ixp4xx_devices));
if (cpu_is_ixp46x()) {
int region;
platform_add_devices(ixp46x_devices,
ARRAY_SIZE(ixp46x_devices));
for (region = 0; region < 7; region++) {
if((*(IXP4XX_EXP_REG(0x4 * region)) & 0x200)) {
ixp4xx_exp_bus_size = SZ_32M;
break;
}
}
}
printk("IXP4xx: Using %luMiB expansion bus window size\n",
ixp4xx_exp_bus_size >> 20);
}
unsigned long ixp4xx_timer_freq = IXP4XX_TIMER_FREQ;
IXP42x HSS support for setting internal clock rate HSS usually uses external clocks, so it's not a big deal. Internal clock is used for direct DTE-DTE connections and when the DCE doesn't provide it's own clock. This also depends on the oscillator frequency. Intel seems to have calculated the clock register settings for 33.33 MHz (66.66 MHz timer base). Their settings seem quite suboptimal both in terms of average frequency (60 ppm is unacceptable for G.703 applications, their primary intended usage(?)) and jitter. Many (most?) platforms use a 33.333 MHz oscillator, a 10 ppm difference from Intel's base. Instead of creating static tables, I've created a procedure to program the HSS clock register. The register consists of 3 parts (A, B, C). The average frequency (= bit rate) is: 66.66x MHz / (A + (B + 1) / (C + 1)) The procedure aims at the closest average frequency, possibly at the cost of increased jitter. Nobody would be able to directly drive an unbufferred transmitter with a HSS anyway, and the frequency error is what it really counts. I've verified the above with an oscilloscope on IXP425. It seems IXP46x and possibly IXP43x use a bit different clock generation algorithm - it looks like the avg frequency is: (on IXP465) 66.66x MHz / (A + B / (C + 1)). Also they use much greater precomputed A and B - on IXP425 it would simply result in more jitter, but I don't know how does it work on IXP46x (perhaps 3 least significant bits aren't used?). Anyway it looks that they were aiming for exactly +60 ppm or -60 ppm, while <1 ppm is typically possible (with a synchronized clock, of course). The attached patch makes it possible to set almost any bit rate (my IXP425 533 MHz quits at > 22 Mb/s if a single port is used, and the minimum is ca. 65 Kb/s). This is independent of MVIP (multi-E1/T1 on one HSS) mode. Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-05 11:59:49 +08:00
EXPORT_SYMBOL(ixp4xx_timer_freq);
void ixp4xx_restart(enum reboot_mode mode, const char *cmd)
{
if (mode == REBOOT_SOFT) {
/* Jump into ROM at address 0 */
soft_restart(0);
} else {
/* Use on-chip reset capability */
/* set the "key" register to enable access to
* "timer" and "enable" registers
*/
*IXP4XX_OSWK = IXP4XX_WDT_KEY;
/* write 0 to the timer register for an immediate reset */
*IXP4XX_OSWT = 0;
*IXP4XX_OSWE = IXP4XX_WDT_RESET_ENABLE | IXP4XX_WDT_COUNT_ENABLE;
}
}
#ifdef CONFIG_PCI
static int ixp4xx_needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
{
return (dma_addr + size) > SZ_64M;
}
static int ixp4xx_platform_notify_remove(struct device *dev)
{
if (dev_is_pci(dev))
dmabounce_unregister_dev(dev);
return 0;
}
#endif
/*
* Setup DMA mask to 64MB on PCI devices and 4 GB on all other things.
*/
static int ixp4xx_platform_notify(struct device *dev)
{
dev->dma_mask = &dev->coherent_dma_mask;
#ifdef CONFIG_PCI
if (dev_is_pci(dev)) {
dev->coherent_dma_mask = DMA_BIT_MASK(28); /* 64 MB */
dmabounce_register_dev(dev, 2048, 4096, ixp4xx_needs_bounce);
return 0;
}
#endif
dev->coherent_dma_mask = DMA_BIT_MASK(32);
return 0;
}
int dma_set_coherent_mask(struct device *dev, u64 mask)
{
if (dev_is_pci(dev))
mask &= DMA_BIT_MASK(28); /* 64 MB */
if ((mask & DMA_BIT_MASK(28)) == DMA_BIT_MASK(28)) {
dev->coherent_dma_mask = mask;
return 0;
}
return -EIO; /* device wanted sub-64MB mask */
}
EXPORT_SYMBOL(dma_set_coherent_mask);
#ifdef CONFIG_IXP4XX_INDIRECT_PCI
/*
* In the case of using indirect PCI, we simply return the actual PCI
* address and our read/write implementation use that to drive the
* access registers. If something outside of PCI is ioremap'd, we
* fallback to the default.
*/
static void __iomem *ixp4xx_ioremap_caller(phys_addr_t addr, size_t size,
unsigned int mtype, void *caller)
{
if (!is_pci_memory(addr))
return __arm_ioremap_caller(addr, size, mtype, caller);
return (void __iomem *)addr;
}
static void ixp4xx_iounmap(volatile void __iomem *addr)
{
if (!is_pci_memory((__force u32)addr))
__iounmap(addr);
}
#endif
void __init ixp4xx_init_early(void)
{
platform_notify = ixp4xx_platform_notify;
#ifdef CONFIG_PCI
platform_notify_remove = ixp4xx_platform_notify_remove;
#endif
#ifdef CONFIG_IXP4XX_INDIRECT_PCI
arch_ioremap_caller = ixp4xx_ioremap_caller;
arch_iounmap = ixp4xx_iounmap;
#endif
}