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[POWERPC] mpc52xx_psc_spi device driver must not touch port_config and cdm 

It is dangerous for an mpc52xx device driver to modify the port_config
register.  If the driver is probed incorrectly, it will change the pin
IO configuration in ways which may not be compatible with the board.
port_config should be set up by the bootloader, or failing that, in
the platform setup code in arch/powerpc/platforms/52xx.

Also, modifying CDM registers directly can cause a race condition with
other drivers.  Instead call a common routine to modify CDM settings.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Dragos Carp <dragos.carp@toptica.com>
This commit is contained in:
Grant Likely 2008-01-24 22:25:31 -07:00
parent c8004a2818
commit 4fb4c55824
1 changed files with 2 additions and 75 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
drivers/spi/mpc52xx_psc_spi.c
View File

@ -330,80 +330,13 @@ static void mpc52xx_psc_spi_cleanup(struct spi_device *spi)
static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
{
struct device_node *np;
struct mpc52xx_cdm __iomem *cdm;
struct mpc52xx_gpio __iomem *gpio;
struct mpc52xx_psc __iomem *psc = mps->psc;
u32 ul;
u32 mclken_div;
int ret = 0;
#if defined(CONFIG_PPC_MERGE)
np = of_find_compatible_node(NULL, NULL, "mpc5200-cdm");
cdm = of_iomap(np, 0);
of_node_put(np);
np = of_find_compatible_node(NULL, NULL, "mpc5200-gpio");
gpio = of_iomap(np, 0);
of_node_put(np);
#else
cdm = ioremap(MPC52xx_PA(MPC52xx_CDM_OFFSET), MPC52xx_CDM_SIZE);
gpio = ioremap(MPC52xx_PA(MPC52xx_GPIO_OFFSET), MPC52xx_GPIO_SIZE);
#endif
if (!cdm || !gpio) {
printk(KERN_ERR "Error mapping CDM/GPIO\n");
ret = -EFAULT;
goto unmap_regs;
}
/* default sysclk is 512MHz */
mclken_div = 0x8000 |
(((mps->sysclk ? mps->sysclk : 512000000) / MCLK) & 0x1FF);
switch (psc_id) {
case 1:
ul = in_be32(&gpio->port_config);
ul &= 0xFFFFFFF8;
ul |= 0x00000006;
out_be32(&gpio->port_config, ul);
out_be16(&cdm->mclken_div_psc1, mclken_div);
ul = in_be32(&cdm->clk_enables);
ul |= 0x00000020;
out_be32(&cdm->clk_enables, ul);
break;
case 2:
ul = in_be32(&gpio->port_config);
ul &= 0xFFFFFF8F;
ul |= 0x00000060;
out_be32(&gpio->port_config, ul);
out_be16(&cdm->mclken_div_psc2, mclken_div);
ul = in_be32(&cdm->clk_enables);
ul |= 0x00000040;
out_be32(&cdm->clk_enables, ul);
break;
case 3:
ul = in_be32(&gpio->port_config);
ul &= 0xFFFFF0FF;
ul |= 0x00000600;
out_be32(&gpio->port_config, ul);
out_be16(&cdm->mclken_div_psc3, mclken_div);
ul = in_be32(&cdm->clk_enables);
ul |= 0x00000080;
out_be32(&cdm->clk_enables, ul);
break;
case 6:
ul = in_be32(&gpio->port_config);
ul &= 0xFF8FFFFF;
ul |= 0x00700000;
out_be32(&gpio->port_config, ul);
out_be16(&cdm->mclken_div_psc6, mclken_div);
ul = in_be32(&cdm->clk_enables);
ul |= 0x00000010;
out_be32(&cdm->clk_enables, ul);
break;
default:
ret = -EINVAL;
goto unmap_regs;
}
mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
/* Reset the PSC into a known state */
out_8(&psc->command, MPC52xx_PSC_RST_RX);
@ -427,12 +360,6 @@ static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
mps->bits_per_word = 8;
unmap_regs:
if (cdm)
iounmap(cdm);
if (gpio)
iounmap(gpio);
return ret;
}