linux-kernel - [RFC PATCH v1 2/6] spi: rockchip: Preset cs-high and clk polarity in setup progress

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Message-Id: <20220211034938.25097-3-jon.lin@rock-chips.com>
Date:   Fri, 11 Feb 2022 11:49:34 +0800
From:   Jon Lin <jon.lin@...k-chips.com>
To:     broonie@...nel.org
Cc:     heiko@...ech.de, linux-spi@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-rockchip@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Jon Lin <jon.lin@...k-chips.com>
Subject: [RFC PATCH v1 2/6] spi: rockchip: Preset cs-high and clk polarity in setup progress

After power up, the cs and clock is in default status, and the cs-high
and clock polarity dts property configuration will take no effect until
the calling of rockchip_spi_config in the first transmission.
So preset them to make sure a correct voltage before the first
transmission coming.

Signed-off-by: Jon Lin <jon.lin@...k-chips.com>
---

 drivers/spi/spi-rockchip.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index 7ac07569e103..1738a2611a2b 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -711,6 +711,26 @@ static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
 	return xfer->len / bytes_per_word >= rs->fifo_len;
 }
 
+static int rockchip_spi_setup(struct spi_device *spi)
+{
+	struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
+	u32 cr0;
+
+	pm_runtime_get_sync(rs->dev);
+
+	cr0 = readl_relaxed(rs->regs + ROCKCHIP_SPI_CTRLR0);
+
+	cr0 |= ((spi->mode & 0x3) << CR0_SCPH_OFFSET);
+	if (spi->mode & SPI_CS_HIGH)
+		cr0 |= BIT(spi->chip_select) << CR0_SOI_OFFSET;
+
+	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
+
+	pm_runtime_put(rs->dev);
+
+	return 0;
+}
+
 static int rockchip_spi_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -837,6 +857,7 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 	ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
 	ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
 
+	ctlr->setup = rockchip_spi_setup;
 	ctlr->set_cs = rockchip_spi_set_cs;
 	ctlr->transfer_one = rockchip_spi_transfer_one;
 	ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
-- 
2.17.1