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

   1 From 2fc7dd0f48d9c2096d76562a1960b78b064701f7 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 27/81] 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 --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
  24 +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
  25 @@ -412,6 +412,20 @@ static bool pwrap_is_fsm_vldclr(struct p
  26         return PWRAP_GET_WACS_FSM(val) == PWRAP_WACS_FSM_WFVLDCLR;
  27  }
  28
  29 +/*
  30 + * Timeout issue sometimes caused by the last read command
  31 + * failed because pmic wrap could not got the FSM_VLDCLR
  32 + * in time after finishing WACS2_CMD. It made state machine
  33 + * still on FSM_VLDCLR and timeout next time.
  34 + * Check the status of FSM and clear the vldclr to recovery the
  35 + * error.
  36 + */
  37 +static inline void pwrap_leave_fsm_vldclr(struct pmic_wrapper *wrp)
  38 +{
  39 +       if (pwrap_is_fsm_vldclr(wrp))
  40 +               pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
  41 +}
  42 +
  43  static bool pwrap_is_sync_idle(struct pmic_wrapper *wrp)
  44  {
  45         return pwrap_readl(wrp, PWRAP_WACS2_RDATA) & PWRAP_STATE_SYNC_IDLE0;
  46 @@ -445,8 +459,10 @@ static int pwrap_write(struct pmic_wrapp
  47         int ret;
  48
  49         ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
  50 -       if (ret)
  51 +       if (ret) {
  52 +               pwrap_leave_fsm_vldclr(wrp);
  53                 return ret;
  54 +       }
  55
  56         pwrap_writel(wrp, (1 << 31) | ((adr >> 1) << 16) | wdata,
  57                         PWRAP_WACS2_CMD);
  58 @@ -459,8 +475,10 @@ static int pwrap_read(struct pmic_wrappe
  59         int ret;
  60
  61         ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
  62 -       if (ret)
  63 +       if (ret) {
  64 +               pwrap_leave_fsm_vldclr(wrp);
  65                 return ret;
  66 +       }
  67
  68         pwrap_writel(wrp, (adr >> 1) << 16, PWRAP_WACS2_CMD);
  69