target/linux/at91/patches-5.10/235-clk-at91-pmc-execute-suspend-resume-only-for-backup-.patch

   1 From 63a0c32028148e91ea91cfbf95841c4ecd69d21b Mon Sep 17 00:00:00 2001
   2 From: Claudiu Beznea <claudiu.beznea@microchip.com>
   3 Date: Mon, 11 Oct 2021 14:27:06 +0300
   4 Subject: [PATCH 235/247] clk: at91: pmc: execute suspend/resume only for
   5  backup mode
   6
   7 Before going to backup mode architecture specific PM code sets the first
   8 word in securam (file arch/arm/mach-at91/pm.c, function at91_pm_begin()).
   9 Thus take this into account when suspending/resuming clocks. This will
  10 avoid executing unnecessary instructions when suspending to non backup
  11 modes.
  12
  13 Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
  14 Link: https://lore.kernel.org/r/20211011112719.3951784-3-claudiu.beznea@microchip.com
  15 Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
  16 Signed-off-by: Stephen Boyd <sboyd@kernel.org>
  17 ---
  18  drivers/clk/at91/pmc.c | 39 +++++++++++++++++++++++++++++++++++++++
  19  1 file changed, 39 insertions(+)
  20
  21 diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
  22 index b2806946a77a..517973062719 100644
  23 --- a/drivers/clk/at91/pmc.c
  24 +++ b/drivers/clk/at91/pmc.c
  25 @@ -8,6 +8,7 @@
  26  #include <linux/clkdev.h>
  27  #include <linux/clk/at91_pmc.h>
  28  #include <linux/of.h>
  29 +#include <linux/of_address.h>
  30  #include <linux/mfd/syscon.h>
  31  #include <linux/platform_device.h>
  32  #include <linux/regmap.h>
  33 @@ -110,13 +111,35 @@ struct pmc_data *pmc_data_allocate(unsigned int ncore, unsigned int nsystem,
  34  }
  35
  36  #ifdef CONFIG_PM
  37 +
  38 +/* Address in SECURAM that say if we suspend to backup mode. */
  39 +static void __iomem *at91_pmc_backup_suspend;
  40 +
  41  static int at91_pmc_suspend(void)
  42  {
  43 +       unsigned int backup;
  44 +
  45 +       if (!at91_pmc_backup_suspend)
  46 +               return 0;
  47 +
  48 +       backup = readl_relaxed(at91_pmc_backup_suspend);
  49 +       if (!backup)
  50 +               return 0;
  51 +
  52         return clk_save_context();
  53  }
  54
  55  static void at91_pmc_resume(void)
  56  {
  57 +       unsigned int backup;
  58 +
  59 +       if (!at91_pmc_backup_suspend)
  60 +               return;
  61 +
  62 +       backup = readl_relaxed(at91_pmc_backup_suspend);
  63 +       if (!backup)
  64 +               return;
  65 +
  66         clk_restore_context();
  67  }
  68
  69 @@ -144,6 +167,22 @@ static int __init pmc_register_ops(void)
  70         }
  71         of_node_put(np);
  72
  73 +       np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam");
  74 +       if (!np)
  75 +               return -ENODEV;
  76 +
  77 +       if (!of_device_is_available(np)) {
  78 +               of_node_put(np);
  79 +               return -ENODEV;
  80 +       }
  81 +       of_node_put(np);
  82 +
  83 +       at91_pmc_backup_suspend = of_iomap(np, 0);
  84 +       if (!at91_pmc_backup_suspend) {
  85 +               pr_warn("%s(): unable to map securam\n", __func__);
  86 +               return -ENOMEM;
  87 +       }
  88 +
  89         register_syscore_ops(&pmc_syscore_ops);
  90
  91         return 0;
  92 --
  93 2.32.0
  94