[openwrt/openwrt] mediatek: mt7623: import patch to fix spi

[LEDE Commits]

dangole pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/90db922f8818edb1faf9b9c9ba71f73119fb6068

commit 90db922f8818edb1faf9b9c9ba71f73119fb6068
Author: Nick Hainke <vincent at systemli.org>
AuthorDate: Sat Jul 24 12:55:20 2021 +0200

    mediatek: mt7623: import patch to fix spi
    
    The patch fixes the fifo rx mode for the mt7623. It is already accepted
    upstream for Linux Kernel 5.15.
    
    To test the spi we can change the dts file to
    
    &spi0 {
            pinctrl-names = "default";
            pinctrl-0 = <&spi0_pins_a>;
            status = "okay";
            spidev: spidev at 0 {
                    compatible = "linux,spidev";
                    spi-max-frequency = <1000000>;
                    reg = <0>;
            };
    };
    
    Afterwards we should see a spidev device under /dev/.
    To test it we can further use spidev-test.
    
    Signed-off-by: Nick Hainke <vincent at systemli.org>
---
 .../mediatek/patches-5.10/000-spi-fix-fifo.patch   | 54 ++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/target/linux/mediatek/patches-5.10/000-spi-fix-fifo.patch b/target/linux/mediatek/patches-5.10/000-spi-fix-fifo.patch
new file mode 100644
index 0000000000..a7ac93a208
--- /dev/null
+++ b/target/linux/mediatek/patches-5.10/000-spi-fix-fifo.patch
@@ -0,0 +1,54 @@
+From 3a70dd2d050331ee4cf5ad9d5c0a32d83ead9a43 Mon Sep 17 00:00:00 2001
+From: Peter Hess <peter.hess at ph-home.de>
+Date: Tue, 6 Jul 2021 14:16:09 +0200
+Subject: spi: mediatek: fix fifo rx mode
+
+In FIFO mode were two problems:
+- RX mode was never handled and
+- in this case the tx_buf pointer was NULL and caused an exception
+
+fix this by handling RX mode in mtk_spi_fifo_transfer
+
+Fixes: a568231f4632 ("spi: mediatek: Add spi bus for Mediatek MT8173")
+Signed-off-by: Peter Hess <peter.hess at ph-home.de>
+Signed-off-by: Frank Wunderlich <frank-w at public-files.de>
+Link: https://lore.kernel.org/r/20210706121609.680534-1-linux@fw-web.de
+Signed-off-by: Mark Brown <broonie at kernel.org>
+---
+ drivers/spi/spi-mt65xx.c | 16 +++++++++++++---
+ 1 file changed, 13 insertions(+), 3 deletions(-)
+
+diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
+index 976f73b9e2998..8d5fa7f1e5069 100644
+--- a/drivers/spi/spi-mt65xx.c
++++ b/drivers/spi/spi-mt65xx.c
+@@ -427,13 +427,23 @@ static int mtk_spi_fifo_transfer(struct spi_master *master,
+ 	mtk_spi_setup_packet(master);
+ 
+ 	cnt = xfer->len / 4;
+-	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
++	if (xfer->tx_buf)
++		iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
++
++	if (xfer->rx_buf)
++		ioread32_rep(mdata->base + SPI_RX_DATA_REG, xfer->rx_buf, cnt);
+ 
+ 	remainder = xfer->len % 4;
+ 	if (remainder > 0) {
+ 		reg_val = 0;
+-		memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
+-		writel(reg_val, mdata->base + SPI_TX_DATA_REG);
++		if (xfer->tx_buf) {
++			memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
++			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
++		}
++		if (xfer->rx_buf) {
++			reg_val = readl(mdata->base + SPI_RX_DATA_REG);
++			memcpy(xfer->rx_buf + (cnt * 4), &reg_val, remainder);
++		}
+ 	}
+ 
+ 	mtk_spi_enable_transfer(master);
+-- 
+cgit 1.2.3-1.el7
+