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Commit 4fb4c558 authored by Grant Likely's avatar Grant Likely
Browse files

[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: default avatarGrant Likely <grant.likely@secretlab.ca>
Acked-by: default avatarDragos Carp <dragos.carp@toptica.com>
parent c8004a28

drivers/spi/mpc52xx_psc_spi.c

+2 −75
Original line number Diff line number Diff line
@@ -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;

}