Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <1552282840-12778-1-git-send-email-qii.wang@mediatek.com> <1552282840-12778-6-git-send-email-qii.wang@mediatek.com>
In-Reply-To: <1552282840-12778-6-git-send-email-qii.wang@mediatek.com>
From:   Nicolas Boichat <drinkcat@chromium.org>
Date:   Mon, 11 Mar 2019 16:34:54 +0800
Message-ID: <CANMq1KDcb108cn4DnEu-=4BHrJjxfKkbCXamtbEsz8Emqv0PSQ@mail.gmail.com>
Subject: Re: [PATCH v6 5/6] i2c: mediatek: Add i2c support for MediaTek MT8183
To:     Qii Wang <qii.wang@mediatek.com>
Cc:     wsa@the-dreams.de, linux-i2c@vger.kernel.org,
        devicetree@vger.kernel.org,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        lkml <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        srv_heupstream <srv_heupstream@mediatek.com>,
        Leilk Liu <leilk.liu@mediatek.com>, xinping.qian@mediatek.com,
        liguo.zhang@mediatek.com, Rob Herring <robh@kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, Mar 11, 2019 at 1:41 PM Qii Wang <qii.wang@mediatek.com> wrote:
>
> Add i2c compatible for MT8183. Compare to MT2712 i2c controller,
> MT8183 has different register offsets. Ltiming_reg is added to
> adjust low width of SCL. Arb clock and dma_sync are needed.
>
> Signed-off-by: Qii Wang <qii.wang@mediatek.com>

LTIMING support could be split as yet-another-subpatch, but otherwise LGTM.

Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

> ---
>  drivers/i2c/busses/i2c-mt65xx.c |   62 +++++++++++++++++++++++++++++++++++++--
>  1 file changed, 60 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> index 6137ad7..745b0d0 100644
> --- a/drivers/i2c/busses/i2c-mt65xx.c
> +++ b/drivers/i2c/busses/i2c-mt65xx.c
> @@ -133,6 +133,7 @@ enum I2C_REGS_OFFSET {
>         OFFSET_DEBUGCTRL,
>         OFFSET_TRANSFER_LEN_AUX,
>         OFFSET_CLOCK_DIV,
> +       OFFSET_LTIMING,
>  };
>
>  static const u16 mt_i2c_regs_v1[] = {
> @@ -162,6 +163,32 @@ enum I2C_REGS_OFFSET {
>         [OFFSET_CLOCK_DIV] = 0x70,
>  };
>
> +static const u16 mt_i2c_regs_v2[] = {
> +       [OFFSET_DATA_PORT] = 0x0,
> +       [OFFSET_SLAVE_ADDR] = 0x4,
> +       [OFFSET_INTR_MASK] = 0x8,
> +       [OFFSET_INTR_STAT] = 0xc,
> +       [OFFSET_CONTROL] = 0x10,
> +       [OFFSET_TRANSFER_LEN] = 0x14,
> +       [OFFSET_TRANSAC_LEN] = 0x18,
> +       [OFFSET_DELAY_LEN] = 0x1c,
> +       [OFFSET_TIMING] = 0x20,
> +       [OFFSET_START] = 0x24,
> +       [OFFSET_EXT_CONF] = 0x28,
> +       [OFFSET_LTIMING] = 0x2c,
> +       [OFFSET_HS] = 0x30,
> +       [OFFSET_IO_CONFIG] = 0x34,
> +       [OFFSET_FIFO_ADDR_CLR] = 0x38,
> +       [OFFSET_TRANSFER_LEN_AUX] = 0x44,
> +       [OFFSET_CLOCK_DIV] = 0x48,
> +       [OFFSET_SOFTRESET] = 0x50,
> +       [OFFSET_DEBUGSTAT] = 0xe0,
> +       [OFFSET_DEBUGCTRL] = 0xe8,
> +       [OFFSET_FIFO_STAT] = 0xf4,
> +       [OFFSET_FIFO_THRESH] = 0xf8,
> +       [OFFSET_DCM_EN] = 0xf88,
> +};
> +
>  struct mtk_i2c_compatible {
>         const struct i2c_adapter_quirks *quirks;
>         const u16 *regs;
> @@ -172,6 +199,7 @@ struct mtk_i2c_compatible {
>         unsigned char support_33bits: 1;
>         unsigned char timing_adjust: 1;
>         unsigned char dma_sync: 1;
> +       unsigned char ltiming_adjust: 1;
>  };
>
>  struct mtk_i2c {
> @@ -195,6 +223,7 @@ struct mtk_i2c {
>         enum mtk_trans_op op;
>         u16 timing_reg;
>         u16 high_speed_reg;
> +       u16 ltiming_reg;
>         unsigned char auto_restart;
>         bool ignore_restart_irq;
>         const struct mtk_i2c_compatible *dev_comp;
> @@ -222,6 +251,7 @@ struct mtk_i2c {
>         .support_33bits = 1,
>         .timing_adjust = 1,
>         .dma_sync = 0,
> +       .ltiming_adjust = 0,
>  };
>
>  static const struct mtk_i2c_compatible mt6577_compat = {
> @@ -234,6 +264,7 @@ struct mtk_i2c {
>         .support_33bits = 0,
>         .timing_adjust = 0,
>         .dma_sync = 0,
> +       .ltiming_adjust = 0,
>  };
>
>  static const struct mtk_i2c_compatible mt6589_compat = {
> @@ -246,6 +277,7 @@ struct mtk_i2c {
>         .support_33bits = 0,
>         .timing_adjust = 0,
>         .dma_sync = 0,
> +       .ltiming_adjust = 0,
>  };
>
>  static const struct mtk_i2c_compatible mt7622_compat = {
> @@ -258,6 +290,7 @@ struct mtk_i2c {
>         .support_33bits = 0,
>         .timing_adjust = 0,
>         .dma_sync = 0,
> +       .ltiming_adjust = 0,
>  };
>
>  static const struct mtk_i2c_compatible mt8173_compat = {
> @@ -269,6 +302,19 @@ struct mtk_i2c {
>         .support_33bits = 1,
>         .timing_adjust = 0,
>         .dma_sync = 0,
> +       .ltiming_adjust = 0,
> +};
> +
> +static const struct mtk_i2c_compatible mt8183_compat = {
> +       .regs = mt_i2c_regs_v2,
> +       .pmic_i2c = 0,
> +       .dcm = 0,
> +       .auto_restart = 1,
> +       .aux_len_reg = 1,
> +       .support_33bits = 1,
> +       .timing_adjust = 1,
> +       .dma_sync = 1,
> +       .ltiming_adjust = 1,
>  };
>
>  static const struct of_device_id mtk_i2c_of_match[] = {
> @@ -277,6 +323,7 @@ struct mtk_i2c {
>         { .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat },
>         { .compatible = "mediatek,mt7622-i2c", .data = &mt7622_compat },
>         { .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat },
> +       { .compatible = "mediatek,mt8183-i2c", .data = &mt8183_compat },
>         {}
>  };
>  MODULE_DEVICE_TABLE(of, mtk_i2c_of_match);
> @@ -361,6 +408,8 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
>
>         mtk_i2c_writew(i2c, i2c->timing_reg, OFFSET_TIMING);
>         mtk_i2c_writew(i2c, i2c->high_speed_reg, OFFSET_HS);
> +       if (i2c->dev_comp->ltiming_adjust)
> +               mtk_i2c_writew(i2c, i2c->ltiming_reg, OFFSET_LTIMING);
>
>         /* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
>         if (i2c->have_pmic)
> @@ -460,6 +509,8 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
>         unsigned int clk_src;
>         unsigned int step_cnt;
>         unsigned int sample_cnt;
> +       unsigned int l_step_cnt;
> +       unsigned int l_sample_cnt;
>         unsigned int target_speed;
>         int ret;
>
> @@ -469,11 +520,11 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
>         if (target_speed > MAX_FS_MODE_SPEED) {
>                 /* Set master code speed register */
>                 ret = mtk_i2c_calculate_speed(i2c, clk_src, MAX_FS_MODE_SPEED,
> -                                             &step_cnt, &sample_cnt);
> +                                             &l_step_cnt, &l_sample_cnt);
>                 if (ret < 0)
>                         return ret;
>
> -               i2c->timing_reg = (sample_cnt << 8) | step_cnt;
> +               i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt;
>
>                 /* Set the high speed mode register */
>                 ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
> @@ -483,6 +534,10 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
>
>                 i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
>                         (sample_cnt << 12) | (step_cnt << 8);
> +
> +               if (i2c->dev_comp->ltiming_adjust)
> +                       i2c->ltiming_reg = (l_sample_cnt << 6) | l_step_cnt |
> +                                          (sample_cnt << 12) | (step_cnt << 9);
>         } else {
>                 ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
>                                               &step_cnt, &sample_cnt);
> @@ -493,6 +548,9 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
>
>                 /* Disable the high speed transaction */
>                 i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
> +
> +               if (i2c->dev_comp->ltiming_adjust)
> +                       i2c->ltiming_reg = (sample_cnt << 6) | step_cnt;
>         }
>
>         return 0;
> --
> 1.7.9.5
>