git.openwrt.org Git - openwrt/staging/ldir.git/blob

   1 From 95e4dfbf33dc0a0843ba20db811f7ea271235e1e Mon Sep 17 00:00:00 2001
   2 From: Kewei Xu <kewei.xu@mediatek.com>
   3 Date: Sun, 10 Oct 2021 15:05:12 +0800
   4 Subject: [PATCH 01/16] i2c: mediatek: Reset the handshake signal between i2c
   5  and dma
   6
   7 Due to changes in the hardware design of the handshaking signal
   8 between i2c and dma, it is necessary to reset the handshaking
   9 signal before each transfer to ensure that the multi-msgs can
  10 be transferred correctly.
  11
  12 Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
  13 Reviewed-by: Qii Wang <qii.wang@mediatek.com>
  14 Signed-off-by: Wolfram Sang <wsa@kernel.org>
  15 ---
  16  drivers/i2c/busses/i2c-mt65xx.c | 26 ++++++++++++++++++++++++++
  17  1 file changed, 26 insertions(+)
  18
  19 --- a/drivers/i2c/busses/i2c-mt65xx.c
  20 +++ b/drivers/i2c/busses/i2c-mt65xx.c
  21 @@ -15,6 +15,7 @@
  22  #include <linux/init.h>
  23  #include <linux/interrupt.h>
  24  #include <linux/io.h>
  25 +#include <linux/iopoll.h>
  26  #include <linux/kernel.h>
  27  #include <linux/mm.h>
  28  #include <linux/module.h>
  29 @@ -49,6 +50,8 @@
  30  #define I2C_RD_TRANAC_VALUE            0x0001
  31  #define I2C_SCL_MIS_COMP_VALUE         0x0000
  32  #define I2C_CHN_CLR_FLAG               0x0000
  33 +#define I2C_RELIABILITY                0x0010
  34 +#define I2C_DMAACK_ENABLE              0x0008
  35
  36  #define I2C_DMA_CON_TX                 0x0000
  37  #define I2C_DMA_CON_RX                 0x0001
  38 @@ -851,6 +854,7 @@ static int mtk_i2c_do_transfer(struct mt
  39         u16 restart_flag = 0;
  40         u16 dma_sync = 0;
  41         u32 reg_4g_mode;
  42 +       u32 reg_dma_reset;
  43         u8 *dma_rd_buf = NULL;
  44         u8 *dma_wr_buf = NULL;
  45         dma_addr_t rpaddr = 0;
  46 @@ -864,6 +868,28 @@ static int mtk_i2c_do_transfer(struct mt
  47
  48         reinit_completion(&i2c->msg_complete);
  49
  50 +       if (i2c->dev_comp->apdma_sync &&
  51 +           i2c->op != I2C_MASTER_WRRD && num > 1) {
  52 +               mtk_i2c_writew(i2c, 0x00, OFFSET_DEBUGCTRL);
  53 +               writel(I2C_DMA_HANDSHAKE_RST | I2C_DMA_WARM_RST,
  54 +                      i2c->pdmabase + OFFSET_RST);
  55 +
  56 +               ret = readw_poll_timeout(i2c->pdmabase + OFFSET_RST,
  57 +                                        reg_dma_reset,
  58 +                                        !(reg_dma_reset & I2C_DMA_WARM_RST),
  59 +                                        0, 100);
  60 +               if (ret) {
  61 +                       dev_err(i2c->dev, "DMA warm reset timeout\n");
  62 +                       return -ETIMEDOUT;
  63 +               }
  64 +
  65 +               writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
  66 +               mtk_i2c_writew(i2c, I2C_HANDSHAKE_RST, OFFSET_SOFTRESET);
  67 +               mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_SOFTRESET);
  68 +               mtk_i2c_writew(i2c, I2C_RELIABILITY | I2C_DMAACK_ENABLE,
  69 +                              OFFSET_DEBUGCTRL);
  70 +       }
  71 +
  72         control_reg = mtk_i2c_readw(i2c, OFFSET_CONTROL) &
  73                         ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
  74         if ((i2c->speed_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) || (left_num >= 1))