target/linux/mediatek/patches-4.4/0027-soc-mediatek-PMIC-wrap-Clear-the-vldclr-if-state-mac.patch

   1 From af4a99b856b584b2426757e905e9b6f39906ce05 Mon Sep 17 00:00:00 2001
   2 From: Henry Chen <henryc.chen@mediatek.com>
   3 Date: Mon, 4 Jan 2016 20:02:52 +0800
   4 Subject: [PATCH 27/53] soc: mediatek: PMIC wrap: Clear the vldclr if state
   5  machine stay on FSM_VLDCLR state.
   6
   7 Sometimes PMIC is too busy to send data in time to cause pmic wrap timeout,
   8 because pmic wrap is waiting for FSM_VLDCLR after finishing WACS2_CMD. It
   9 just return error when issue happened, so the state machine will stay on
  10 FSM_VLDCLR state when data send back later by PMIC and timeout again in next
  11 time because pmic wrap waiting for FSM_IDLE state at the beginning of the
  12 read/write function.
  13
  14 Clear the vldclr when timeout if state machine stay on FSM_VLDCLR.
  15
  16 Signed-off-by: Henry Chen <henryc.chen@mediatek.com>
  17 Tested-by: Ricky Liang <jcliang@chromium.org>
  18 Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
  19 ---
  20  drivers/soc/mediatek/mtk-pmic-wrap.c |   22 ++++++++++++++++++++--
  21  1 file changed, 20 insertions(+), 2 deletions(-)
  22
  23 diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
  24 index 105597a..696071b 100644
  25 --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
  26 +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
  27 @@ -412,6 +412,20 @@ static bool pwrap_is_fsm_vldclr(struct pmic_wrapper *wrp)
  28         return PWRAP_GET_WACS_FSM(val) == PWRAP_WACS_FSM_WFVLDCLR;
  29  }
  30
  31 +/*
  32 + * Timeout issue sometimes caused by the last read command
  33 + * failed because pmic wrap could not got the FSM_VLDCLR
  34 + * in time after finishing WACS2_CMD. It made state machine
  35 + * still on FSM_VLDCLR and timeout next time.
  36 + * Check the status of FSM and clear the vldclr to recovery the
  37 + * error.
  38 + */
  39 +static inline void pwrap_leave_fsm_vldclr(struct pmic_wrapper *wrp)
  40 +{
  41 +       if (pwrap_is_fsm_vldclr(wrp))
  42 +               pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
  43 +}
  44 +
  45  static bool pwrap_is_sync_idle(struct pmic_wrapper *wrp)
  46  {
  47         return pwrap_readl(wrp, PWRAP_WACS2_RDATA) & PWRAP_STATE_SYNC_IDLE0;
  48 @@ -445,8 +459,10 @@ static int pwrap_write(struct pmic_wrapper *wrp, u32 adr, u32 wdata)
  49         int ret;
  50
  51         ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
  52 -       if (ret)
  53 +       if (ret) {
  54 +               pwrap_leave_fsm_vldclr(wrp);
  55                 return ret;
  56 +       }
  57
  58         pwrap_writel(wrp, (1 << 31) | ((adr >> 1) << 16) | wdata,
  59                         PWRAP_WACS2_CMD);
  60 @@ -459,8 +475,10 @@ static int pwrap_read(struct pmic_wrapper *wrp, u32 adr, u32 *rdata)
  61         int ret;
  62
  63         ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
  64 -       if (ret)
  65 +       if (ret) {
  66 +               pwrap_leave_fsm_vldclr(wrp);
  67                 return ret;
  68 +       }
  69
  70         pwrap_writel(wrp, (adr >> 1) << 16, PWRAP_WACS2_CMD);
  71
  72 --
  73 1.7.10.4
  74