android_kernel_xiaomi_sm8350/drivers/pnp/support.c
Bjorn Helgaas 25eb846189 PNP: add pnp_eisa_id_to_string()
Converting the EISA ID to a string is messy and error-prone, and
we might as well use the same code for ISAPNP and PNPBIOS.

PNPACPI uses the conversion done by the ACPI core with
acpi_ex_eisa_id_to_string().

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2008-04-29 03:22:16 -04:00

54 lines
1.5 KiB
C

/*
* support.c - standard functions for the use of pnp protocol drivers
*
* Copyright 2003 Adam Belay <ambx1@neo.rr.com>
*/
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/pnp.h>
#include "base.h"
/**
* pnp_is_active - Determines if a device is active based on its current
* resources
* @dev: pointer to the desired PnP device
*/
int pnp_is_active(struct pnp_dev *dev)
{
if (!pnp_port_start(dev, 0) && pnp_port_len(dev, 0) <= 1 &&
!pnp_mem_start(dev, 0) && pnp_mem_len(dev, 0) <= 1 &&
pnp_irq(dev, 0) == -1 && pnp_dma(dev, 0) == -1)
return 0;
else
return 1;
}
EXPORT_SYMBOL(pnp_is_active);
/*
* Functionally similar to acpi_ex_eisa_id_to_string(), but that's
* buried in the ACPI CA, and we can't depend on it being present.
*/
void pnp_eisa_id_to_string(u32 id, char *str)
{
id = be32_to_cpu(id);
/*
* According to the specs, the first three characters are five-bit
* compressed ASCII, and the left-over high order bit should be zero.
* However, the Linux ISAPNP code historically used six bits for the
* first character, and there seem to be IDs that depend on that,
* e.g., "nEC8241" in the Linux 8250_pnp serial driver and the
* FreeBSD sys/pc98/cbus/sio_cbus.c driver.
*/
str[0] = 'A' + ((id >> 26) & 0x3f) - 1;
str[1] = 'A' + ((id >> 21) & 0x1f) - 1;
str[2] = 'A' + ((id >> 16) & 0x1f) - 1;
str[3] = hex_asc((id >> 12) & 0xf);
str[4] = hex_asc((id >> 8) & 0xf);
str[5] = hex_asc((id >> 4) & 0xf);
str[6] = hex_asc((id >> 0) & 0xf);
str[7] = '\0';
}