diff options
Diffstat (limited to 'drivers/clk/at91/pmc.c')
| -rw-r--r-- | drivers/clk/at91/pmc.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c new file mode 100644 index 000000000..1fa27f4ea --- /dev/null +++ b/drivers/clk/at91/pmc.c @@ -0,0 +1,215 @@ +/* + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/of.h> +#include <linux/mfd/syscon.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/syscore_ops.h> + +#include <asm/proc-fns.h> + +#include "pmc.h" + +#define PMC_MAX_IDS 128 +#define PMC_MAX_PCKS 8 + +int of_at91_get_clk_range(struct device_node *np, const char *propname, + struct clk_range *range) +{ + u32 min, max; + int ret; + + ret = of_property_read_u32_index(np, propname, 0, &min); + if (ret) + return ret; + + ret = of_property_read_u32_index(np, propname, 1, &max); + if (ret) + return ret; + + if (range) { + range->min = min; + range->max = max; + } + + return 0; +} +EXPORT_SYMBOL_GPL(of_at91_get_clk_range); + +#ifdef CONFIG_PM +static struct regmap *pmcreg; + +static u8 registered_ids[PMC_MAX_IDS]; +static u8 registered_pcks[PMC_MAX_PCKS]; + +static struct +{ + u32 scsr; + u32 pcsr0; + u32 uckr; + u32 mor; + u32 mcfr; + u32 pllar; + u32 mckr; + u32 usb; + u32 imr; + u32 pcsr1; + u32 pcr[PMC_MAX_IDS]; + u32 audio_pll0; + u32 audio_pll1; + u32 pckr[PMC_MAX_PCKS]; +} pmc_cache; + +/* + * As Peripheral ID 0 is invalid on AT91 chips, the identifier is stored + * without alteration in the table, and 0 is for unused clocks. + */ +void pmc_register_id(u8 id) +{ + int i; + + for (i = 0; i < PMC_MAX_IDS; i++) { + if (registered_ids[i] == 0) { + registered_ids[i] = id; + break; + } + if (registered_ids[i] == id) + break; + } +} + +/* + * As Programmable Clock 0 is valid on AT91 chips, there is an offset + * of 1 between the stored value and the real clock ID. + */ +void pmc_register_pck(u8 pck) +{ + int i; + + for (i = 0; i < PMC_MAX_PCKS; i++) { + if (registered_pcks[i] == 0) { + registered_pcks[i] = pck + 1; + break; + } + if (registered_pcks[i] == (pck + 1)) + break; + } +} + +static int pmc_suspend(void) +{ + int i; + u8 num; + + regmap_read(pmcreg, AT91_PMC_SCSR, &pmc_cache.scsr); + regmap_read(pmcreg, AT91_PMC_PCSR, &pmc_cache.pcsr0); + regmap_read(pmcreg, AT91_CKGR_UCKR, &pmc_cache.uckr); + regmap_read(pmcreg, AT91_CKGR_MOR, &pmc_cache.mor); + regmap_read(pmcreg, AT91_CKGR_MCFR, &pmc_cache.mcfr); + regmap_read(pmcreg, AT91_CKGR_PLLAR, &pmc_cache.pllar); + regmap_read(pmcreg, AT91_PMC_MCKR, &pmc_cache.mckr); + regmap_read(pmcreg, AT91_PMC_USB, &pmc_cache.usb); + regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.imr); + regmap_read(pmcreg, AT91_PMC_PCSR1, &pmc_cache.pcsr1); + + for (i = 0; registered_ids[i]; i++) { + regmap_write(pmcreg, AT91_PMC_PCR, + (registered_ids[i] & AT91_PMC_PCR_PID_MASK)); + regmap_read(pmcreg, AT91_PMC_PCR, + &pmc_cache.pcr[registered_ids[i]]); + } + for (i = 0; registered_pcks[i]; i++) { + num = registered_pcks[i] - 1; + regmap_read(pmcreg, AT91_PMC_PCKR(num), &pmc_cache.pckr[num]); + } + + return 0; +} + +static bool pmc_ready(unsigned int mask) +{ + unsigned int status; + + regmap_read(pmcreg, AT91_PMC_SR, &status); + + return ((status & mask) == mask) ? 1 : 0; +} + +static void pmc_resume(void) +{ + int i; + u8 num; + u32 tmp; + u32 mask = AT91_PMC_MCKRDY | AT91_PMC_LOCKA; + + regmap_read(pmcreg, AT91_PMC_MCKR, &tmp); + if (pmc_cache.mckr != tmp) + pr_warn("MCKR was not configured properly by the firmware\n"); + regmap_read(pmcreg, AT91_CKGR_PLLAR, &tmp); + if (pmc_cache.pllar != tmp) + pr_warn("PLLAR was not configured properly by the firmware\n"); + + regmap_write(pmcreg, AT91_PMC_SCER, pmc_cache.scsr); + regmap_write(pmcreg, AT91_PMC_PCER, pmc_cache.pcsr0); + regmap_write(pmcreg, AT91_CKGR_UCKR, pmc_cache.uckr); + regmap_write(pmcreg, AT91_CKGR_MOR, pmc_cache.mor); + regmap_write(pmcreg, AT91_CKGR_MCFR, pmc_cache.mcfr); + regmap_write(pmcreg, AT91_PMC_USB, pmc_cache.usb); + regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.imr); + regmap_write(pmcreg, AT91_PMC_PCER1, pmc_cache.pcsr1); + + for (i = 0; registered_ids[i]; i++) { + regmap_write(pmcreg, AT91_PMC_PCR, + pmc_cache.pcr[registered_ids[i]] | + AT91_PMC_PCR_CMD); + } + for (i = 0; registered_pcks[i]; i++) { + num = registered_pcks[i] - 1; + regmap_write(pmcreg, AT91_PMC_PCKR(num), pmc_cache.pckr[num]); + } + + if (pmc_cache.uckr & AT91_PMC_UPLLEN) + mask |= AT91_PMC_LOCKU; + + while (!pmc_ready(mask)) + cpu_relax(); +} + +static struct syscore_ops pmc_syscore_ops = { + .suspend = pmc_suspend, + .resume = pmc_resume, +}; + +static const struct of_device_id sama5d2_pmc_dt_ids[] = { + { .compatible = "atmel,sama5d2-pmc" }, + { /* sentinel */ } +}; + +static int __init pmc_register_ops(void) +{ + struct device_node *np; + + np = of_find_matching_node(NULL, sama5d2_pmc_dt_ids); + + pmcreg = syscon_node_to_regmap(np); + if (IS_ERR(pmcreg)) + return PTR_ERR(pmcreg); + + register_syscore_ops(&pmc_syscore_ops); + + return 0; +} +/* This has to happen before arch_initcall because of the tcb_clksrc driver */ +postcore_initcall(pmc_register_ops); +#endif |