diff options
| author | Claudiu Beznea <claudiu.beznea@microchip.com> | 2021-10-11 14:27:05 +0300 |
|---|---|---|
| committer | Stephen Boyd <sboyd@kernel.org> | 2021-10-27 04:27:41 +0300 |
| commit | 36971566ea7a519bcde1830f39b6aa37c34e0fb4 (patch) | |
| tree | 5e2bc834ef97c1b35b5ecce1cf7a01bc4c377cba /drivers/clk/at91/clk-usb.c | |
| parent | c405f5c15e9f6094f2fa1658e73e56f3058e2122 (diff) | |
| download | linux-36971566ea7a519bcde1830f39b6aa37c34e0fb4.tar.xz | |
clk: at91: re-factor clocks suspend/resume
SAMA5D2 and SAMA7G5 have a special power saving mode (backup mode) where
most of the SoC's components are powered off (including PMC). Resuming
from this mode is done with the help of bootloader. Peripherals are not
aware of the power saving mode thus most of them are disabling clocks in
proper suspend API and re-enable them in resume API without taking into
account the previously setup rate. Moreover some of the peripherals are
acting as wakeup sources and are not disabling the clocks in this
scenario, when suspending. Since backup mode cuts the power for
peripherals, in resume part these clocks needs to be re-configured.
The initial PMC suspend/resume code was designed only for SAMA5D2's PMC
(as it was the only one supporting backup mode). SAMA7G supports also
backup mode and its PMC is different (few new functionalities, different
registers offsets, different offsets in registers for each
functionalities). To address both SAMA5D2 and SAMA7G5 PMC add
.save_context()/.resume_context() support to each clocks driver and call
this from PMC driver.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20211011112719.3951784-2-claudiu.beznea@microchip.com
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/at91/clk-usb.c')
| -rw-r--r-- | drivers/clk/at91/clk-usb.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-usb.c b/drivers/clk/at91/clk-usb.c index 31d5c45e30d7..b0696a928aa9 100644 --- a/drivers/clk/at91/clk-usb.c +++ b/drivers/clk/at91/clk-usb.c @@ -24,6 +24,7 @@ struct at91sam9x5_clk_usb { struct clk_hw hw; struct regmap *regmap; + struct at91_clk_pms pms; u32 usbs_mask; u8 num_parents; }; @@ -148,12 +149,38 @@ static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate, return 0; } +static int at91sam9x5_usb_save_context(struct clk_hw *hw) +{ + struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw); + struct clk_hw *parent_hw = clk_hw_get_parent(hw); + + usb->pms.parent = at91sam9x5_clk_usb_get_parent(hw); + usb->pms.parent_rate = clk_hw_get_rate(parent_hw); + usb->pms.rate = at91sam9x5_clk_usb_recalc_rate(hw, usb->pms.parent_rate); + + return 0; +} + +static void at91sam9x5_usb_restore_context(struct clk_hw *hw) +{ + struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw); + int ret; + + ret = at91sam9x5_clk_usb_set_parent(hw, usb->pms.parent); + if (ret) + return; + + at91sam9x5_clk_usb_set_rate(hw, usb->pms.rate, usb->pms.parent_rate); +} + static const struct clk_ops at91sam9x5_usb_ops = { .recalc_rate = at91sam9x5_clk_usb_recalc_rate, .determine_rate = at91sam9x5_clk_usb_determine_rate, .get_parent = at91sam9x5_clk_usb_get_parent, .set_parent = at91sam9x5_clk_usb_set_parent, .set_rate = at91sam9x5_clk_usb_set_rate, + .save_context = at91sam9x5_usb_save_context, + .restore_context = at91sam9x5_usb_restore_context, }; static int at91sam9n12_clk_usb_enable(struct clk_hw *hw) |