legacy_serial.c

来自「LINUX 2.6.17.4的源码」· C语言 代码 · 共 554 行 · 第 1/2 页

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <linux/serial_core.h>
#include <linux/console.h>
#include <linux/pci.h>
#include <asm/io.h>
#include <asm/mmu.h>
#include <asm/prom.h>
#include <asm/serial.h>
#include <asm/udbg.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>

#undef DEBUG

#ifdef DEBUG
#define DBG(fmt...) do { printk(fmt); } while(0)
#else
#define DBG(fmt...) do { } while(0)
#endif

#define MAX_LEGACY_SERIAL_PORTS	8

static struct plat_serial8250_port
legacy_serial_ports[MAX_LEGACY_SERIAL_PORTS+1];
static struct legacy_serial_info {
	struct device_node		*np;
	unsigned int			speed;
	unsigned int			clock;
	phys_addr_t			taddr;
} legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
static unsigned int legacy_serial_count;
static int legacy_serial_console = -1;

static int __init add_legacy_port(struct device_node *np, int want_index,
				  int iotype, phys_addr_t base,
				  phys_addr_t taddr, unsigned long irq,
				  upf_t flags)
{
	u32 *clk, *spd, clock = BASE_BAUD * 16;
	int index;

	/* get clock freq. if present */
	clk = (u32 *)get_property(np, "clock-frequency", NULL);
	if (clk && *clk)
		clock = *clk;

	/* get default speed if present */
	spd = (u32 *)get_property(np, "current-speed", NULL);

	/* If we have a location index, then try to use it */
	if (want_index >= 0 && want_index < MAX_LEGACY_SERIAL_PORTS)
		index = want_index;
	else
		index = legacy_serial_count;

	/* if our index is still out of range, that mean that
	 * array is full, we could scan for a free slot but that
	 * make little sense to bother, just skip the port
	 */
	if (index >= MAX_LEGACY_SERIAL_PORTS)
		return -1;
	if (index >= legacy_serial_count)
		legacy_serial_count = index + 1;

	/* Check if there is a port who already claimed our slot */
	if (legacy_serial_infos[index].np != 0) {
		/* if we still have some room, move it, else override */
		if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
			printk(KERN_INFO "Moved legacy port %d -> %d\n",
			       index, legacy_serial_count);
			legacy_serial_ports[legacy_serial_count] =
				legacy_serial_ports[index];
			legacy_serial_infos[legacy_serial_count] =
				legacy_serial_infos[index];
			legacy_serial_count++;
		} else {
			printk(KERN_INFO "Replacing legacy port %d\n", index);
		}
	}

	/* Now fill the entry */
	memset(&legacy_serial_ports[index], 0,
	       sizeof(struct plat_serial8250_port));
	if (iotype == UPIO_PORT)
		legacy_serial_ports[index].iobase = base;
	else
		legacy_serial_ports[index].mapbase = base;
	legacy_serial_ports[index].iotype = iotype;
	legacy_serial_ports[index].uartclk = clock;
	legacy_serial_ports[index].irq = irq;
	legacy_serial_ports[index].flags = flags;
	legacy_serial_infos[index].taddr = taddr;
	legacy_serial_infos[index].np = of_node_get(np);
	legacy_serial_infos[index].clock = clock;
	legacy_serial_infos[index].speed = spd ? *spd : 0;

	printk(KERN_INFO "Found legacy serial port %d for %s\n",
	       index, np->full_name);
	printk(KERN_INFO "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
	       (iotype == UPIO_PORT) ? "port" : "mem",
	       (unsigned long long)base, (unsigned long long)taddr, irq,
	       legacy_serial_ports[index].uartclk,
	       legacy_serial_infos[index].speed);

	return index;
}

static int __init add_legacy_soc_port(struct device_node *np,
				      struct device_node *soc_dev)
{
	phys_addr_t addr;
	u32 *addrp;
	upf_t flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ;

	/* We only support ports that have a clock frequency properly
	 * encoded in the device-tree.
	 */
	if (get_property(np, "clock-frequency", NULL) == NULL)
		return -1;

	/* Get the address */
	addrp = of_get_address(soc_dev, 0, NULL, NULL);
	if (addrp == NULL)
		return -1;

	addr = of_translate_address(soc_dev, addrp);

	/* Add port, irq will be dealt with later. We passed a translated
	 * IO port value. It will be fixed up later along with the irq
	 */
	return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags);
}

static int __init add_legacy_isa_port(struct device_node *np,
				      struct device_node *isa_brg)
{
	u32 *reg;
	char *typep;
	int index = -1;
	phys_addr_t taddr;

	/* Get the ISA port number */
	reg = (u32 *)get_property(np, "reg", NULL);
	if (reg == NULL)
		return -1;

	/* Verify it's an IO port, we don't support anything else */
	if (!(reg[0] & 0x00000001))
		return -1;

	/* Now look for an "ibm,aix-loc" property that gives us ordering
	 * if any...
	 */
	typep = (char *)get_property(np, "ibm,aix-loc", NULL);

	/* If we have a location index, then use it */
	if (typep && *typep == 'S')
		index = simple_strtol(typep+1, NULL, 0) - 1;

	/* Translate ISA address */
	taddr = of_translate_address(np, reg);

	/* Add port, irq will be dealt with later */
	return add_legacy_port(np, index, UPIO_PORT, reg[1], taddr, NO_IRQ, UPF_BOOT_AUTOCONF);

}

#ifdef CONFIG_PCI
static int __init add_legacy_pci_port(struct device_node *np,
				      struct device_node *pci_dev)
{
	phys_addr_t addr, base;
	u32 *addrp;
	unsigned int flags;
	int iotype, index = -1, lindex = 0;

	/* We only support ports that have a clock frequency properly
	 * encoded in the device-tree (that is have an fcode). Anything
	 * else can't be used that early and will be normally probed by
	 * the generic 8250_pci driver later on. The reason is that 8250
	 * compatible UARTs on PCI need all sort of quirks (port offsets
	 * etc...) that this code doesn't know about
	 */
	if (get_property(np, "clock-frequency", NULL) == NULL)
		return -1;

	/* Get the PCI address. Assume BAR 0 */
	addrp = of_get_pci_address(pci_dev, 0, NULL, &flags);
	if (addrp == NULL)
		return -1;

	/* We only support BAR 0 for now */
	iotype = (flags & IORESOURCE_MEM) ? UPIO_MEM : UPIO_PORT;
	addr = of_translate_address(pci_dev, addrp);

	/* Set the IO base to the same as the translated address for MMIO,
	 * or to the domain local IO base for PIO (it will be fixed up later)
	 */
	if (iotype == UPIO_MEM)
		base = addr;
	else
		base = addrp[2];

	/* Try to guess an index... If we have subdevices of the pci dev,
	 * we get to their "reg" property
	 */
	if (np != pci_dev) {
		u32 *reg = (u32 *)get_property(np, "reg", NULL);
		if (reg && (*reg < 4))
			index = lindex = *reg;
	}

	/* Local index means it's the Nth port in the PCI chip. Unfortunately
	 * the offset to add here is device specific. We know about those
	 * EXAR ports and we default to the most common case. If your UART
	 * doesn't work for these settings, you'll have to add your own special
	 * cases here
	 */
	if (device_is_compatible(pci_dev, "pci13a8,152") ||
	    device_is_compatible(pci_dev, "pci13a8,154") ||
	    device_is_compatible(pci_dev, "pci13a8,158")) {
		addr += 0x200 * lindex;
		base += 0x200 * lindex;
	} else {
		addr += 8 * lindex;
		base += 8 * lindex;
	}

	/* Add port, irq will be dealt with later. We passed a translated
	 * IO port value. It will be fixed up later along with the irq
	 */
	return add_legacy_port(np, index, iotype, base, addr, NO_IRQ, UPF_BOOT_AUTOCONF);
}
#endif

static void __init setup_legacy_serial_console(int console)
{
	struct legacy_serial_info *info =
		&legacy_serial_infos[console];
	void __iomem *addr;

	if (info->taddr == 0)
		return;
	addr = ioremap(info->taddr, 0x1000);
	if (addr == NULL)
		return;
	if (info->speed == 0)
		info->speed = udbg_probe_uart_speed(addr, info->clock);
	DBG("default console speed = %d\n", info->speed);
	udbg_init_uart(addr, info->speed, info->clock);
}

/*
 * This is called very early, as part of setup_system() or eventually
 * setup_arch(), basically before anything else in this file. This function
 * will try to build a list of all the available 8250-compatible serial ports
 * in the machine using the Open Firmware device-tree. It currently only deals
 * with ISA and PCI busses but could be extended. It allows a very early boot
 * console to be initialized, that list is also used later to provide 8250 with
 * the machine non-PCI ports and to properly pick the default console port
 */
void __init find_legacy_serial_ports(void)
{
	struct device_node *np, *stdout = NULL;
	char *path;
	int index;

	DBG(" -> find_legacy_serial_port()\n");

	/* Now find out if one of these is out firmware console */
	path = (char *)get_property(of_chosen, "linux,stdout-path", NULL);
	if (path != NULL) {
		stdout = of_find_node_by_path(path);
		if (stdout)