From: Neil Armstrong <narmstrong@baylibre.com>
To: Sunny Luo <sunny.luo@amlogic.com>, Mark Brown <broonie@kernel.org>
Cc: Yixun Lan <yixun.lan@amlogic.com>,
Jerome Brunet <jbrunet@baylibre.com>,
Kevin Hilman <khilman@baylibre.com>,
Carlo Caione <carlo@caione.org>,
Jianxin Pan <jianxin.pan@amlogic.com>,
Xingyu Chen <xingyu.chen@amlogic.com>,
linux-spi@vger.kernel.org, linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/3] spi: meson-axg: enhance output enable feature
Date: Thu, 13 Dec 2018 09:53:00 +0100 [thread overview]
Message-ID: <6ba11b0a-3629-5378-61c7-3cc364237f5c@baylibre.com> (raw)
In-Reply-To: <1544690354-16409-3-git-send-email-sunny.luo@amlogic.com>
Hi Sunny,
On 13/12/2018 09:39, Sunny Luo wrote:
> The SPICC controller in Meson-AXG is capable of driving the CLK/MOSI/SS
> signal lines through the idle state (between two transmission operation),
> which avoid the signals floating in unexpected state.
This is welcome, because it's really missing on GX...
I tried implementing it with pinctrl at [1], but it's complex.
Can you provide more info on how we should implement in on GX to be on par ?
[1] https://github.com/superna9999/linux/commit/9c3a95659dd532d186556c1570c54d79ea5a4d45
>
> Signed-off-by: Sunny Luo <sunny.luo@amlogic.com>
> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
> ---
> drivers/spi/spi-meson-spicc.c | 28 ++++++++++++++++++++++++++--
> 1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c
> index b56249d..0384c28 100644
> --- a/drivers/spi/spi-meson-spicc.c
> +++ b/drivers/spi/spi-meson-spicc.c
> @@ -115,6 +115,13 @@
>
> #define SPICC_DWADDR 0x24 /* Write Address of DMA */
>
> +#define SPICC_ENH_CTL0 0x38 /* Enhanced Feature */
> +#define SPICC_ENH_MOSI_OEN BIT(25)
> +#define SPICC_ENH_CLK_OEN BIT(26)
> +#define SPICC_ENH_CS_OEN BIT(27)
> +#define SPICC_ENH_CLK_CS_DELAY_EN BIT(28)
> +#define SPICC_ENH_MAIN_CLK_AO BIT(29)
> +
> #define writel_bits_relaxed(mask, val, addr) \
> writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr)
>
> @@ -123,6 +130,7 @@
>
> struct meson_spicc_data {
> unsigned int max_speed_hz;
> + bool has_oen;
> };
>
> struct meson_spicc_device {
> @@ -145,6 +153,19 @@ struct meson_spicc_device {
> bool is_last_burst;
> };
>
> +static void meson_spicc_oen_enable(struct meson_spicc_device *spicc)
> +{
> + u32 conf;
> +
> + if (!spicc->data->has_oen)
> + return;
> +
> + conf = readl_relaxed(spicc->base + SPICC_ENH_CTL0) |
> + SPICC_ENH_MOSI_OEN | SPICC_ENH_CLK_OEN | SPICC_ENH_CS_OEN;
> +
> + writel_relaxed(conf, spicc->base + SPICC_ENH_CTL0);
> +}
> +
> static inline bool meson_spicc_txfull(struct meson_spicc_device *spicc)
> {
> return !!FIELD_GET(SPICC_TF,
> @@ -453,6 +474,8 @@ static int meson_spicc_prepare_message(struct spi_master *master,
>
> writel_bits_relaxed(BIT(24), BIT(24), spicc->base + SPICC_TESTREG);
>
> + meson_spicc_oen_enable(spicc);
> +
> return 0;
> }
>
> @@ -610,11 +633,12 @@ static int meson_spicc_remove(struct platform_device *pdev)
> }
>
> static const struct meson_spicc_data meson_spicc_gx_data = {
> - .max_speed_hz = 30000000,
> + .max_speed_hz = 30000000,
Nitpick, but I would have kept the indentation here ...
> };
>
> static const struct meson_spicc_data meson_spicc_axg_data = {
> - .max_speed_hz = 80000000,
> + .max_speed_hz = 80000000,
> + .has_oen = true,
same here
> };
>
> static const struct of_device_id meson_spicc_of_match[] = {
>
Anywy it's nitpick,
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
next prev parent reply other threads:[~2018-12-13 8:53 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-13 8:39 [PATCH v2 0/3] spi: meson-axg: add few enhanced features Sunny Luo
2018-12-13 8:39 ` [PATCH v2 1/3] spi: meson-axg: support MAX 80M clock Sunny Luo
2018-12-13 8:49 ` Neil Armstrong
2018-12-13 11:55 ` Sunny Luo
2018-12-13 8:39 ` [PATCH v2 2/3] spi: meson-axg: enhance output enable feature Sunny Luo
2018-12-13 8:53 ` Neil Armstrong [this message]
2018-12-13 13:12 ` Sunny Luo
2018-12-13 9:04 ` Jerome Brunet
2018-12-13 11:53 ` Mark Brown
2018-12-13 12:50 ` Sunny Luo
2018-12-13 13:31 ` Sunny Luo
2018-12-13 8:39 ` [PATCH v2 3/3] spi: meson-axg: add a linear clock divider support Sunny Luo
2018-12-13 8:55 ` Neil Armstrong
2018-12-13 9:28 ` Jerome Brunet
2018-12-13 14:37 ` Sunny Luo
2018-12-13 15:01 ` Jerome Brunet
2018-12-13 13:25 ` Sunny Luo
2018-12-15 18:31 ` kbuild test robot
2020-02-19 8:17 ` [PATCH v2 0/3] spi: meson-axg: add few enhanced features Neil Armstrong
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