diff options
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/52xx/mpc52xx_common.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_common.c b/arch/powerpc/platforms/52xx/mpc52xx_common.c index a46bad0c2339..6e905314ad5d 100644 --- a/arch/powerpc/platforms/52xx/mpc52xx_common.c +++ b/arch/powerpc/platforms/52xx/mpc52xx_common.c @@ -12,9 +12,11 @@ #undef DEBUG +#include <linux/gpio.h> #include <linux/kernel.h> #include <linux/spinlock.h> #include <linux/of_platform.h> +#include <linux/of_gpio.h> #include <asm/io.h> #include <asm/prom.h> #include <asm/mpc52xx.h> @@ -82,6 +84,14 @@ mpc5200_setup_xlb_arbiter(void) iounmap(xlb); } +/* + * This variable is mapped in mpc52xx_map_common_devices and + * used in mpc5200_psc_ac97_gpio_reset(). + */ +static DEFINE_SPINLOCK(gpio_lock); +struct mpc52xx_gpio __iomem *simple_gpio; +struct mpc52xx_gpio_wkup __iomem *wkup_gpio; + /** * mpc52xx_declare_of_platform_devices: register internal devices and children * of the localplus bus to the of_platform @@ -109,6 +119,15 @@ static struct of_device_id mpc52xx_cdm_ids[] __initdata = { { .compatible = "mpc5200-cdm", }, /* old */ {} }; +static const struct of_device_id mpc52xx_gpio_simple[] = { + { .compatible = "fsl,mpc5200-gpio", }, + {} +}; +static const struct of_device_id mpc52xx_gpio_wkup[] = { + { .compatible = "fsl,mpc5200-gpio-wkup", }, + {} +}; + /** * mpc52xx_map_common_devices: iomap devices required by common code @@ -135,6 +154,16 @@ mpc52xx_map_common_devices(void) np = of_find_matching_node(NULL, mpc52xx_cdm_ids); mpc52xx_cdm = of_iomap(np, 0); of_node_put(np); + + /* simple_gpio registers */ + np = of_find_matching_node(NULL, mpc52xx_gpio_simple); + simple_gpio = of_iomap(np, 0); + of_node_put(np); + + /* wkup_gpio registers */ + np = of_find_matching_node(NULL, mpc52xx_gpio_wkup); + wkup_gpio = of_iomap(np, 0); + of_node_put(np); } /** @@ -233,3 +262,80 @@ mpc52xx_restart(char *cmd) while (1); } + +#define PSC1_RESET 0x1 +#define PSC1_SYNC 0x4 +#define PSC1_SDATA_OUT 0x1 +#define PSC2_RESET 0x2 +#define PSC2_SYNC (0x4<<4) +#define PSC2_SDATA_OUT (0x1<<4) +#define MPC52xx_GPIO_PSC1_MASK 0x7 +#define MPC52xx_GPIO_PSC2_MASK (0x7<<4) + +/** + * mpc5200_psc_ac97_gpio_reset: Use gpio pins to reset the ac97 bus + * + * @psc: psc number to reset (only psc 1 and 2 support ac97) + */ +int mpc5200_psc_ac97_gpio_reset(int psc_number) +{ + unsigned long flags; + u32 gpio; + u32 mux; + int out; + int reset; + int sync; + + if ((!simple_gpio) || (!wkup_gpio)) + return -ENODEV; + + switch (psc_number) { + case 0: + reset = PSC1_RESET; /* AC97_1_RES */ + sync = PSC1_SYNC; /* AC97_1_SYNC */ + out = PSC1_SDATA_OUT; /* AC97_1_SDATA_OUT */ + gpio = MPC52xx_GPIO_PSC1_MASK; + break; + case 1: + reset = PSC2_RESET; /* AC97_2_RES */ + sync = PSC2_SYNC; /* AC97_2_SYNC */ + out = PSC2_SDATA_OUT; /* AC97_2_SDATA_OUT */ + gpio = MPC52xx_GPIO_PSC2_MASK; + break; + default: + pr_err(__FILE__ ": Unable to determine PSC, no ac97 " + "cold-reset will be performed\n"); + return -ENODEV; + } + + spin_lock_irqsave(&gpio_lock, flags); + + /* Reconfiure pin-muxing to gpio */ + mux = in_be32(&simple_gpio->port_config); + out_be32(&simple_gpio->port_config, mux & (~gpio)); + + /* enable gpio pins for output */ + setbits8(&wkup_gpio->wkup_gpioe, reset); + setbits32(&simple_gpio->simple_gpioe, sync | out); + + setbits8(&wkup_gpio->wkup_ddr, reset); + setbits32(&simple_gpio->simple_ddr, sync | out); + + /* Assert cold reset */ + clrbits32(&simple_gpio->simple_dvo, sync | out); + clrbits8(&wkup_gpio->wkup_dvo, reset); + + /* wait at lease 1 us */ + udelay(2); + + /* Deassert reset */ + setbits8(&wkup_gpio->wkup_dvo, reset); + + /* Restore pin-muxing */ + out_be32(&simple_gpio->port_config, mux); + + spin_unlock_irqrestore(&gpio_lock, flags); + + return 0; +} +EXPORT_SYMBOL(mpc5200_psc_ac97_gpio_reset); |