target/linux/layerscape/patches-5.4/808-i2c-0012-i2c-imx-correct-code-of-errata-A-010650-for-layersca.patch

   1 From 27ea8554c8fdcdf1d7aba5ce47630d878ce96691 Mon Sep 17 00:00:00 2001
   2 From: Biwen Li <biwen.li@nxp.com>
   3 Date: Thu, 24 Oct 2019 13:14:44 +0800
   4 Subject: [PATCH] i2c: imx: correct code of errata A-010650 for layerscape
   5  platform
   6
   7 - Simplify code with helper function i2c_imx_clr_al_bit
   8 - Fix an error about clearing arbitration lost bit
   9 - Fix an error that not set I2Cx_IBCR following by
  10   the workaround of A-010650 (in step 5)
  11
  12 Reviewed-by: Clark Wang <xiaoning.wang@nxp.com>
  13 Signed-off-by: Biwen Li <biwen.li@nxp.com>
  14 ---
  15  drivers/i2c/busses/i2c-imx.c | 38 +++++++++++++++++++-------------------
  16  1 file changed, 19 insertions(+), 19 deletions(-)
  17
  18 --- a/drivers/i2c/busses/i2c-imx.c
  19 +++ b/drivers/i2c/busses/i2c-imx.c
  20 @@ -516,6 +516,14 @@ static void i2c_imx_clear_irq(struct imx
  21         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
  22  }
  23
  24 +/* Clear arbitration lost bit */
  25 +static void i2c_imx_clr_al_bit(unsigned int status, struct imx_i2c_struct *i2c_imx)
  26 +{
  27 +       status &= ~I2SR_IAL;
  28 +       status |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IAL);
  29 +       imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
  30 +}
  31 +
  32  static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
  33  {
  34         unsigned long orig_jiffies = jiffies;
  35 @@ -528,7 +536,7 @@ static int i2c_imx_bus_busy(struct imx_i
  36
  37                 /* check for arbitration lost */
  38                 if (temp & I2SR_IAL) {
  39 -                       i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
  40 +                       i2c_imx_clr_al_bit(temp, i2c_imx);
  41                         return -EAGAIN;
  42                 }
  43
  44 @@ -724,14 +732,6 @@ static void i2c_imx_clr_if_bit(unsigned
  45         imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
  46  }
  47
  48 -/* Clear arbitration lost bit */
  49 -static void i2c_imx_clr_al_bit(unsigned int status, struct imx_i2c_struct *i2c_imx)
  50 -{
  51 -       status &= ~I2SR_IAL;
  52 -       status |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IAL);
  53 -       imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
  54 -}
  55 -
  56  static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx)
  57  {
  58         unsigned int status;
  59 @@ -1080,12 +1080,14 @@ static int i2c_imx_recovery_for_layersca
  60         gpio_set_value(i2c_imx->gpio, 1);
  61
  62         /*
  63 -        * Set I2Cx_IBCR = 0h00 to generate a STOP and then
  64 -        * set I2Cx_IBCR = 0h80 to reset
  65 +        * Set I2Cx_IBCR = 0h00 to generate a STOP
  66          */
  67 -       temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
  68 -       temp &= ~(I2CR_MSTA | I2CR_MTX);
  69 -       imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
  70 +       imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
  71 +
  72 +       /*
  73 +        * Set I2Cx_IBCR = 0h80 to reset the I2Cx controller
  74 +        */
  75 +       imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode | I2CR_IEN, i2c_imx, IMX_I2C_I2CR);
  76
  77         /* Restore the saved value of the register SCFG_RCWPMUXCR0 */
  78         if (i2c_imx->need_set_pmuxcr == 1) {
  79 @@ -1099,10 +1101,9 @@ static int i2c_imx_recovery_for_layersca
  80          * I2C_IBSR[IBAL] = 1
  81          */
  82         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
  83 -       if (temp & I2SR_IAL) {
  84 -               temp &= ~I2SR_IAL;
  85 -               imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
  86 -       }
  87 +       if (temp & I2SR_IAL)
  88 +               i2c_imx_clr_al_bit(temp, i2c_imx);
  89 +
  90         return 0;
  91  }
  92