diff options
author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2017-06-08 02:36:47 +0200 |
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committer | Stephen Boyd <sboyd@codeaurora.org> | 2017-06-29 18:47:35 -0700 |
commit | b3b02eac33eddda88992962d920b46348bb086da (patch) | |
tree | 7f905d035b2db5a24d60de9b0d72a5be819164b3 /drivers/clk/at91/pmc.c | |
parent | 682430e87734799ff2d71311d29f04e86f10f2cc (diff) | |
download | linux-b3b02eac33eddda88992962d920b46348bb086da.tar.bz2 |
clk: at91: Add sama5d2 suspend/resume
On sama5d2, VDD core maybe be cut while in suspend. This means registers
will be lost. Ensure they are saved and restored properly.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk/at91/pmc.c')
-rw-r--r-- | drivers/clk/at91/pmc.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c index 526df5ba042d..775af473fe11 100644 --- a/drivers/clk/at91/pmc.c +++ b/drivers/clk/at91/pmc.c @@ -13,12 +13,16 @@ #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 + int of_at91_get_clk_range(struct device_node *np, const char *propname, struct clk_range *range) { @@ -41,3 +45,128 @@ int of_at91_get_clk_range(struct device_node *np, const char *propname, 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 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; +} pmc_cache; + +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; + } +} + +static int pmc_suspend(void) +{ + int i; + + regmap_read(pmcreg, AT91_PMC_IMR, &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]]); + } + + return 0; +} + +static void pmc_resume(void) +{ + int i, ret = 0; + u32 tmp; + + 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_IMR, 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); + } + + if (pmc_cache.uckr & AT91_PMC_UPLLEN) { + ret = regmap_read_poll_timeout(pmcreg, AT91_PMC_SR, tmp, + !(tmp & AT91_PMC_LOCKU), + 10, 5000); + if (ret) + pr_crit("USB PLL didn't lock when resuming\n"); + } +} + +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 |