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authorGrant Likely <grant.likely@secretlab.ca>2008-01-24 22:25:31 -0700
committerGrant Likely <grant.likely@secretlab.ca>2008-01-26 15:32:19 -0700
commit4fb4c5582475452d3bf7c5072ef2d15ee06f7723 (patch)
tree9e75d2795deafb6601fb31c858874ebd554a4135 /drivers/spi
parentc8004a28186110657aa3e75135a6b96ebfa3e8f0 (diff)
downloadlinux-4fb4c5582475452d3bf7c5072ef2d15ee06f7723.tar.bz2
[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>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/mpc52xx_psc_spi.c77
1 files changed, 2 insertions, 75 deletions
diff --git a/drivers/spi/mpc52xx_psc_spi.c b/drivers/spi/mpc52xx_psc_spi.c
index a3ebc632a477..253ed5682a6d 100644
--- a/drivers/spi/mpc52xx_psc_spi.c
+++ b/drivers/spi/mpc52xx_psc_spi.c
@@ -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;
}