u-boot/drivers/misc/fsl_pmic.c
Wolfgang Denk 54841ab50c Make sure that argv[] argument pointers are not modified.
The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands.  Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".

This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:

int main (int argc, char **argv)
{
	while (--argc > 0 && **++argv == '-') {
/* ====> */	while (*++*argv) {
			switch (**argv) {
			case 'd':
				debug++;
				break;
			...
			default:
				usage ();
			}
		}
	}
	...
}

The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell.  With the modification, the compiler will prevent this with
an
	error: increment of read-only location '*argv'

N.B.: The code above can be trivially rewritten like this:

	while (--argc > 0 && **++argv == '-') {
		char *arg = *argv;
		while (*++arg) {
			switch (*arg) {
			...

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2010-07-04 23:55:42 +02:00

200 lines
3.7 KiB
C

/*
* (C) Copyright 2008-2009 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <config.h>
#include <common.h>
#include <spi.h>
#include <asm/errno.h>
#include <linux/types.h>
#include <fsl_pmic.h>
static struct spi_slave *slave;
struct spi_slave *pmic_spi_probe(void)
{
return spi_setup_slave(CONFIG_FSL_PMIC_BUS,
CONFIG_FSL_PMIC_CS,
CONFIG_FSL_PMIC_CLK,
CONFIG_FSL_PMIC_MODE);
}
void pmic_spi_free(struct spi_slave *slave)
{
if (slave)
spi_free_slave(slave);
}
u32 pmic_reg(u32 reg, u32 val, u32 write)
{
u32 pmic_tx, pmic_rx;
if (!slave) {
slave = pmic_spi_probe();
if (!slave)
return -1;
}
if (reg > 63 || write > 1) {
printf("<reg num> = %d is invalid. Should be less then 63\n",
reg);
return -1;
}
if (spi_claim_bus(slave))
return -1;
pmic_tx = (write << 31) | (reg << 25) | (val & 0x00FFFFFF);
if (spi_xfer(slave, 4 << 3, &pmic_tx, &pmic_rx,
SPI_XFER_BEGIN | SPI_XFER_END)) {
spi_release_bus(slave);
return -1;
}
if (write) {
pmic_tx &= ~(1 << 31);
if (spi_xfer(slave, 4 << 3, &pmic_tx, &pmic_rx,
SPI_XFER_BEGIN | SPI_XFER_END)) {
spi_release_bus(slave);
return -1;
}
}
spi_release_bus(slave);
return pmic_rx;
}
void pmic_reg_write(u32 reg, u32 value)
{
pmic_reg(reg, value, 1);
}
u32 pmic_reg_read(u32 reg)
{
return pmic_reg(reg, 0, 0);
}
void pmic_show_pmic_info(void)
{
u32 rev_id;
rev_id = pmic_reg_read(REG_IDENTIFICATION);
printf("PMIC ID: 0x%08x [Rev: ", rev_id);
switch (rev_id & 0x1F) {
case 0x1:
puts("1.0");
break;
case 0x9:
puts("1.1");
break;
case 0xA:
puts("1.2");
break;
case 0x10:
puts("2.0");
break;
case 0x11:
puts("2.1");
break;
case 0x18:
puts("3.0");
break;
case 0x19:
puts("3.1");
break;
case 0x1A:
puts("3.2");
break;
case 0x2:
puts("3.2A");
break;
case 0x1B:
puts("3.3");
break;
case 0x1D:
puts("3.5");
break;
default:
puts("unknown");
break;
}
puts("]\n");
}
static void pmic_dump(int numregs)
{
u32 val;
int i;
pmic_show_pmic_info();
for (i = 0; i < numregs; i++) {
val = pmic_reg_read(i);
if (!(i % 8))
printf ("\n0x%02x: ", i);
printf("%08x ", val);
}
puts("\n");
}
int do_pmic(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
char *cmd;
int nregs;
u32 val;
/* at least two arguments please */
if (argc < 2) {
cmd_usage(cmdtp);
return 1;
}
cmd = argv[1];
if (strcmp(cmd, "dump") == 0) {
if (argc < 3) {
cmd_usage(cmdtp);
return 1;
}
nregs = simple_strtoul(argv[2], NULL, 16);
pmic_dump(nregs);
return 0;
}
if (strcmp(cmd, "write") == 0) {
if (argc < 4) {
cmd_usage(cmdtp);
return 1;
}
nregs = simple_strtoul(argv[2], NULL, 16);
val = simple_strtoul(argv[3], NULL, 16);
pmic_reg_write(nregs, val);
return 0;
}
/* No subcommand found */
return 1;
}
U_BOOT_CMD(
pmic, CONFIG_SYS_MAXARGS, 1, do_pmic,
"Freescale PMIC (Atlas)",
"dump [numregs] dump registers\n"
"pmic write <reg> <value> - write register"
);