diff options
Diffstat (limited to 'arch/powerpc/platforms/52xx/mpc52xx_common.c')
| -rw-r--r-- | arch/powerpc/platforms/52xx/mpc52xx_common.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_common.c b/arch/powerpc/platforms/52xx/mpc52xx_common.c new file mode 100644 index 000000000..b4938e344 --- /dev/null +++ b/arch/powerpc/platforms/52xx/mpc52xx_common.c @@ -0,0 +1,306 @@ +/* + * + * Utility functions for the Freescale MPC52xx. + * + * Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com> + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + * + */ + +#undef DEBUG + +#include <linux/gpio.h> +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.h> +#include <linux/export.h> +#include <asm/io.h> +#include <asm/mpc52xx.h> + +/* MPC5200 device tree match tables */ +static const struct of_device_id mpc52xx_xlb_ids[] __initconst = { + { .compatible = "fsl,mpc5200-xlb", }, + { .compatible = "mpc5200-xlb", }, + {} +}; +static const struct of_device_id mpc52xx_bus_ids[] __initconst = { + { .compatible = "fsl,mpc5200-immr", }, + { .compatible = "fsl,mpc5200b-immr", }, + { .compatible = "simple-bus", }, + + /* depreciated matches; shouldn't be used in new device trees */ + { .compatible = "fsl,lpb", }, + { .type = "builtin", .compatible = "mpc5200", }, /* efika */ + { .type = "soc", .compatible = "mpc5200", }, /* lite5200 */ + {} +}; + +/* + * This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart(). + * Permanent mapping is required because mpc52xx_restart() can be called + * from interrupt context while node mapping (which calls ioremap()) + * cannot be used at such point. + */ +static DEFINE_SPINLOCK(mpc52xx_lock); +static struct mpc52xx_gpt __iomem *mpc52xx_wdt; +static struct mpc52xx_cdm __iomem *mpc52xx_cdm; + +/* + * Configure the XLB arbiter settings to match what Linux expects. + */ +void __init +mpc5200_setup_xlb_arbiter(void) +{ + struct device_node *np; + struct mpc52xx_xlb __iomem *xlb; + + np = of_find_matching_node(NULL, mpc52xx_xlb_ids); + xlb = of_iomap(np, 0); + of_node_put(np); + if (!xlb) { + printk(KERN_ERR __FILE__ ": " + "Error mapping XLB in mpc52xx_setup_cpu(). " + "Expect some abnormal behavior\n"); + return; + } + + /* Configure the XLB Arbiter priorities */ + out_be32(&xlb->master_pri_enable, 0xff); + out_be32(&xlb->master_priority, 0x11111111); + + /* + * Disable XLB pipelining + * (cfr errate 292. We could do this only just before ATA PIO + * transaction and re-enable it afterwards ...) + * Not needed on MPC5200B. + */ + if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR) + out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS); + + 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 + * bus. + */ +void __init mpc52xx_declare_of_platform_devices(void) +{ + /* Find all the 'platform' devices and register them. */ + if (of_platform_populate(NULL, mpc52xx_bus_ids, NULL, NULL)) + pr_err(__FILE__ ": Error while populating devices from DT\n"); +} + +/* + * match tables used by mpc52xx_map_common_devices() + */ +static const struct of_device_id mpc52xx_gpt_ids[] __initconst = { + { .compatible = "fsl,mpc5200-gpt", }, + { .compatible = "mpc5200-gpt", }, /* old */ + {} +}; +static const struct of_device_id mpc52xx_cdm_ids[] __initconst = { + { .compatible = "fsl,mpc5200-cdm", }, + { .compatible = "mpc5200-cdm", }, /* old */ + {} +}; +static const struct of_device_id mpc52xx_gpio_simple[] __initconst = { + { .compatible = "fsl,mpc5200-gpio", }, + {} +}; +static const struct of_device_id mpc52xx_gpio_wkup[] __initconst = { + { .compatible = "fsl,mpc5200-gpio-wkup", }, + {} +}; + + +/** + * mpc52xx_map_common_devices: iomap devices required by common code + */ +void __init +mpc52xx_map_common_devices(void) +{ + struct device_node *np; + + /* mpc52xx_wdt is mapped here and used in mpc52xx_restart, + * possibly from a interrupt context. wdt is only implement + * on a gpt0, so check has-wdt property before mapping. + */ + for_each_matching_node(np, mpc52xx_gpt_ids) { + if (of_property_read_bool(np, "fsl,has-wdt") || + of_property_read_bool(np, "has-wdt")) { + mpc52xx_wdt = of_iomap(np, 0); + of_node_put(np); + break; + } + } + + /* Clock Distribution Module, used by PSC clock setting function */ + 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); +} + +/** + * mpc52xx_set_psc_clkdiv: Set clock divider in the CDM for PSC ports + * + * @psc_id: id of psc port; must be 1,2,3 or 6 + * @clkdiv: clock divider value to put into CDM PSC register. + */ +int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv) +{ + unsigned long flags; + u16 __iomem *reg; + u32 val; + u32 mask; + u32 mclken_div; + + if (!mpc52xx_cdm) + return -ENODEV; + + mclken_div = 0x8000 | (clkdiv & 0x1FF); + switch (psc_id) { + case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break; + case 2: reg = &mpc52xx_cdm->mclken_div_psc2; mask = 0x40; break; + case 3: reg = &mpc52xx_cdm->mclken_div_psc3; mask = 0x80; break; + case 6: reg = &mpc52xx_cdm->mclken_div_psc6; mask = 0x10; break; + default: + return -ENODEV; + } + + /* Set the rate and enable the clock */ + spin_lock_irqsave(&mpc52xx_lock, flags); + out_be16(reg, mclken_div); + val = in_be32(&mpc52xx_cdm->clk_enables); + out_be32(&mpc52xx_cdm->clk_enables, val | mask); + spin_unlock_irqrestore(&mpc52xx_lock, flags); + + return 0; +} +EXPORT_SYMBOL(mpc52xx_set_psc_clkdiv); + +/** + * mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer + */ +void __noreturn mpc52xx_restart(char *cmd) +{ + local_irq_disable(); + + /* Turn on the watchdog and wait for it to expire. + * It effectively does a reset. */ + if (mpc52xx_wdt) { + out_be32(&mpc52xx_wdt->mode, 0x00000000); + out_be32(&mpc52xx_wdt->count, 0x000000ff); + out_be32(&mpc52xx_wdt->mode, 0x00009004); + } else + printk(KERN_ERR __FILE__ ": " + "mpc52xx_restart: Can't access wdt. " + "Restart impossible, system halted.\n"); + + 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); + + /* Reconfigure 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 for 1 us */ + udelay(1); + + /* Deassert reset */ + setbits8(&wkup_gpio->wkup_dvo, reset); + + /* wait at least 200ns */ + /* 7 ~= (200ns * timebase) / ns2sec */ + __delay(7); + + /* 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); |