realtek: backport spi-realtek-rtl driver from 5.12 to 5.10

This patch backports "spi-realtek-rtl" driver to Kernel 5.10 from 5.12.
"MACH_REALTEK_RTL" is used as a platform name in upstream, but "RTL838X"
is used in OpenWrt, so update the dependency by the additional patch.

Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
This commit is contained in:
INAGAKI Hiroshi 2021-05-06 19:30:58 +09:00 committed by Adrian Schmutzler
parent 1651bd9bc6
commit 0b000cbfe0
3 changed files with 322 additions and 0 deletions

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From 6acbd614c2c8d3b8de5fb7605d6e24b9b3a8a17b Mon Sep 17 00:00:00 2001
From: Bert Vermeulen <bert@biot.com>
Date: Wed, 20 Jan 2021 14:59:27 +0100
Subject: spi: Realtek RTL838x/RTL839x SPI controller
Signed-off-by: Bert Vermeulen <bert@biot.com>
Link: https://lore.kernel.org/r/20210120135928.246054-2-bert@biot.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---
.../devicetree/bindings/spi/realtek,rtl-spi.yaml | 41 ++++++++++++++++++++++
1 file changed, 41 insertions(+)
create mode 100644 Documentation/devicetree/bindings/spi/realtek,rtl-spi.yaml
diff --git a/Documentation/devicetree/bindings/spi/realtek,rtl-spi.yaml b/Documentation/devicetree/bindings/spi/realtek,rtl-spi.yaml
new file mode 100644
index 0000000000000..30a62a211984f
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/realtek,rtl-spi.yaml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/realtek,rtl-spi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Realtek RTL838x/RTL839x SPI controller
+
+maintainers:
+ - Bert Vermeulen <bert@biot.com>
+ - Birger Koblitz <mail@birger-koblitz.de>
+
+allOf:
+ - $ref: "spi-controller.yaml#"
+
+properties:
+ compatible:
+ oneOf:
+ - const: realtek,rtl8380-spi
+ - const: realtek,rtl8382-spi
+ - const: realtek,rtl8391-spi
+ - const: realtek,rtl8392-spi
+ - const: realtek,rtl8393-spi
+
+ reg:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ spi: spi@1200 {
+ compatible = "realtek,rtl8382-spi";
+ reg = <0x1200 0x100>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
--
cgit 1.2.3-1.el7

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From a8af5cc2ff1e804694629a8ef320935629dd15ba Mon Sep 17 00:00:00 2001
From: Bert Vermeulen <bert@biot.com>
Date: Wed, 20 Jan 2021 14:59:28 +0100
Subject: spi: realtek-rtl: Add support for Realtek RTL838x/RTL839x SPI
controllers
This driver likely also supports earlier (RTL8196) and later (RTL93xx)
SoCs.
The SPI hardware in these SoCs is specifically intended for connecting NOR
bootflash chips, and only used for that in dozens of examined devices.
However boiled down to basics, it's really just a half-duplex SPI
controller.
The hardware appears to have a vestigial second chip-select control, but
it hasn't been seen in the wild and is thus not supported.
Signed-off-by: Bert Vermeulen <bert@biot.com>
Link: https://lore.kernel.org/r/20210120135928.246054-3-bert@biot.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---
drivers/spi/Makefile | 1 +
drivers/spi/spi-realtek-rtl.c | 209 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 210 insertions(+)
create mode 100644 drivers/spi/spi-realtek-rtl.c
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -94,6 +94,7 @@ obj-$(CONFIG_SPI_QCOM_QSPI) += spi-qcom
obj-$(CONFIG_SPI_QUP) += spi-qup.o
obj-$(CONFIG_SPI_ROCKCHIP) += spi-rockchip.o
obj-$(CONFIG_SPI_RB4XX) += spi-rb4xx.o
+obj-$(CONFIG_MACH_REALTEK_RTL) += spi-realtek-rtl.o
obj-$(CONFIG_SPI_RPCIF) += spi-rpc-if.o
obj-$(CONFIG_SPI_RSPI) += spi-rspi.o
obj-$(CONFIG_SPI_S3C24XX) += spi-s3c24xx-hw.o
--- /dev/null
+++ b/drivers/spi/spi-realtek-rtl.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mod_devicetable.h>
+#include <linux/spi/spi.h>
+
+struct rtspi {
+ void __iomem *base;
+};
+
+/* SPI Flash Configuration Register */
+#define RTL_SPI_SFCR 0x00
+#define RTL_SPI_SFCR_RBO BIT(28)
+#define RTL_SPI_SFCR_WBO BIT(27)
+
+/* SPI Flash Control and Status Register */
+#define RTL_SPI_SFCSR 0x08
+#define RTL_SPI_SFCSR_CSB0 BIT(31)
+#define RTL_SPI_SFCSR_CSB1 BIT(30)
+#define RTL_SPI_SFCSR_RDY BIT(27)
+#define RTL_SPI_SFCSR_CS BIT(24)
+#define RTL_SPI_SFCSR_LEN_MASK ~(0x03 << 28)
+#define RTL_SPI_SFCSR_LEN1 (0x00 << 28)
+#define RTL_SPI_SFCSR_LEN4 (0x03 << 28)
+
+/* SPI Flash Data Register */
+#define RTL_SPI_SFDR 0x0c
+
+#define REG(x) (rtspi->base + x)
+
+
+static void rt_set_cs(struct spi_device *spi, bool active)
+{
+ struct rtspi *rtspi = spi_controller_get_devdata(spi->controller);
+ u32 value;
+
+ /* CS0 bit is active low */
+ value = readl(REG(RTL_SPI_SFCSR));
+ if (active)
+ value |= RTL_SPI_SFCSR_CSB0;
+ else
+ value &= ~RTL_SPI_SFCSR_CSB0;
+ writel(value, REG(RTL_SPI_SFCSR));
+}
+
+static void set_size(struct rtspi *rtspi, int size)
+{
+ u32 value;
+
+ value = readl(REG(RTL_SPI_SFCSR));
+ value &= RTL_SPI_SFCSR_LEN_MASK;
+ if (size == 4)
+ value |= RTL_SPI_SFCSR_LEN4;
+ else if (size == 1)
+ value |= RTL_SPI_SFCSR_LEN1;
+ writel(value, REG(RTL_SPI_SFCSR));
+}
+
+static inline void wait_ready(struct rtspi *rtspi)
+{
+ while (!(readl(REG(RTL_SPI_SFCSR)) & RTL_SPI_SFCSR_RDY))
+ cpu_relax();
+}
+static void send4(struct rtspi *rtspi, const u32 *buf)
+{
+ wait_ready(rtspi);
+ set_size(rtspi, 4);
+ writel(*buf, REG(RTL_SPI_SFDR));
+}
+
+static void send1(struct rtspi *rtspi, const u8 *buf)
+{
+ wait_ready(rtspi);
+ set_size(rtspi, 1);
+ writel(buf[0] << 24, REG(RTL_SPI_SFDR));
+}
+
+static void rcv4(struct rtspi *rtspi, u32 *buf)
+{
+ wait_ready(rtspi);
+ set_size(rtspi, 4);
+ *buf = readl(REG(RTL_SPI_SFDR));
+}
+
+static void rcv1(struct rtspi *rtspi, u8 *buf)
+{
+ wait_ready(rtspi);
+ set_size(rtspi, 1);
+ *buf = readl(REG(RTL_SPI_SFDR)) >> 24;
+}
+
+static int transfer_one(struct spi_controller *ctrl, struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct rtspi *rtspi = spi_controller_get_devdata(ctrl);
+ void *rx_buf;
+ const void *tx_buf;
+ int cnt;
+
+ tx_buf = xfer->tx_buf;
+ rx_buf = xfer->rx_buf;
+ cnt = xfer->len;
+ if (tx_buf) {
+ while (cnt >= 4) {
+ send4(rtspi, tx_buf);
+ tx_buf += 4;
+ cnt -= 4;
+ }
+ while (cnt) {
+ send1(rtspi, tx_buf);
+ tx_buf++;
+ cnt--;
+ }
+ } else if (rx_buf) {
+ while (cnt >= 4) {
+ rcv4(rtspi, rx_buf);
+ rx_buf += 4;
+ cnt -= 4;
+ }
+ while (cnt) {
+ rcv1(rtspi, rx_buf);
+ rx_buf++;
+ cnt--;
+ }
+ }
+
+ spi_finalize_current_transfer(ctrl);
+
+ return 0;
+}
+
+static void init_hw(struct rtspi *rtspi)
+{
+ u32 value;
+
+ /* Turn on big-endian byte ordering */
+ value = readl(REG(RTL_SPI_SFCR));
+ value |= RTL_SPI_SFCR_RBO | RTL_SPI_SFCR_WBO;
+ writel(value, REG(RTL_SPI_SFCR));
+
+ value = readl(REG(RTL_SPI_SFCSR));
+ /* Permanently disable CS1, since it's never used */
+ value |= RTL_SPI_SFCSR_CSB1;
+ /* Select CS0 for use */
+ value &= RTL_SPI_SFCSR_CS;
+ writel(value, REG(RTL_SPI_SFCSR));
+}
+
+static int realtek_rtl_spi_probe(struct platform_device *pdev)
+{
+ struct spi_controller *ctrl;
+ struct rtspi *rtspi;
+ int err;
+
+ ctrl = devm_spi_alloc_master(&pdev->dev, sizeof(*rtspi));
+ if (!ctrl) {
+ dev_err(&pdev->dev, "Error allocating SPI controller\n");
+ return -ENOMEM;
+ }
+ platform_set_drvdata(pdev, ctrl);
+ rtspi = spi_controller_get_devdata(ctrl);
+
+ rtspi->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+ if (IS_ERR(rtspi->base)) {
+ dev_err(&pdev->dev, "Could not map SPI register address");
+ return -ENOMEM;
+ }
+
+ init_hw(rtspi);
+
+ ctrl->dev.of_node = pdev->dev.of_node;
+ ctrl->flags = SPI_CONTROLLER_HALF_DUPLEX;
+ ctrl->set_cs = rt_set_cs;
+ ctrl->transfer_one = transfer_one;
+
+ err = devm_spi_register_controller(&pdev->dev, ctrl);
+ if (err) {
+ dev_err(&pdev->dev, "Could not register SPI controller\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+
+static const struct of_device_id realtek_rtl_spi_of_ids[] = {
+ { .compatible = "realtek,rtl8380-spi" },
+ { .compatible = "realtek,rtl8382-spi" },
+ { .compatible = "realtek,rtl8391-spi" },
+ { .compatible = "realtek,rtl8392-spi" },
+ { .compatible = "realtek,rtl8393-spi" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, realtek_rtl_spi_of_ids);
+
+static struct platform_driver realtek_rtl_spi_driver = {
+ .probe = realtek_rtl_spi_probe,
+ .driver = {
+ .name = "realtek-rtl-spi",
+ .of_match_table = realtek_rtl_spi_of_ids,
+ },
+};
+
+module_platform_driver(realtek_rtl_spi_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Bert Vermeulen <bert@biot.com>");
+MODULE_DESCRIPTION("Realtek RTL SPI driver");

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--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -94,7 +94,7 @@ obj-$(CONFIG_SPI_QCOM_QSPI) += spi-qcom
obj-$(CONFIG_SPI_QUP) += spi-qup.o
obj-$(CONFIG_SPI_ROCKCHIP) += spi-rockchip.o
obj-$(CONFIG_SPI_RB4XX) += spi-rb4xx.o
-obj-$(CONFIG_MACH_REALTEK_RTL) += spi-realtek-rtl.o
+obj-$(CONFIG_RTL838X) += spi-realtek-rtl.o
obj-$(CONFIG_SPI_RPCIF) += spi-rpc-if.o
obj-$(CONFIG_SPI_RSPI) += spi-rspi.o
obj-$(CONFIG_SPI_S3C24XX) += spi-s3c24xx-hw.o