From patchwork Tue Dec 29 23:19:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bert Vermeulen X-Patchwork-Id: 354137 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A31DAC433DB for ; Tue, 29 Dec 2020 23:25:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 618D1207B7 for ; Tue, 29 Dec 2020 23:25:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726189AbgL2XY4 (ORCPT ); Tue, 29 Dec 2020 18:24:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726161AbgL2XY4 (ORCPT ); Tue, 29 Dec 2020 18:24:56 -0500 X-Greylist: delayed 299 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 29 Dec 2020 15:24:16 PST Received: from yawp.biot.com (yawp.biot.com [IPv6:2a01:4f8:10a:8e::fce2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54D24C061799 for ; Tue, 29 Dec 2020 15:24:16 -0800 (PST) Received: from debian-spamd by yawp.biot.com with sa-checked (Exim 4.93) (envelope-from ) id 1kuOGp-00Aceo-R5 for linux-spi@vger.kernel.org; Wed, 30 Dec 2020 00:19:16 +0100 Received: from [2a02:578:460c:1:ae1f:6bff:fed1:9ca8] (helo=sumner.biot.com) by yawp.biot.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1kuOGg-00Acds-Qy; Wed, 30 Dec 2020 00:19:06 +0100 Received: from bert by sumner.biot.com with local (Exim 4.93) (envelope-from ) id 1kuOGg-00Ajhq-Be; Wed, 30 Dec 2020 00:19:06 +0100 From: Bert Vermeulen To: Mark Brown , Rob Herring , Birger Koblitz , linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Bert Vermeulen Subject: [PATCH RESEND v2 2/2] Add support for Realtek RTL838x/RTL839x SoC SPI controllers Date: Wed, 30 Dec 2020 00:19:04 +0100 Message-Id: <20201229231904.2558916-2-bert@biot.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201229231904.2558916-1-bert@biot.com> References: <20201229231904.2558916-1-bert@biot.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org 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 --- (resent due to mail trouble) Notes: v2: rewrote from spi-nor driver to regular spi driver, implementing only set_cs() and transfer_one() (Thanks Chuanhong Guo!) MAINTAINERS | 6 ++ drivers/spi/Kconfig | 7 ++ drivers/spi/Makefile | 1 + drivers/spi/spi-realtek.c | 215 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 229 insertions(+) create mode 100644 drivers/spi/spi-realtek.c diff --git a/MAINTAINERS b/MAINTAINERS index ad0e34bf8453..311e5413b1dd 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15048,6 +15048,12 @@ F: Documentation/devicetree/bindings/net/dsa/realtek-smi.txt F: drivers/net/dsa/realtek-smi* F: drivers/net/dsa/rtl83* +REALTEK RTL83XX SPI DRIVER +M: Bert Vermeulen +M: Birger Koblitz +S: Maintained +F: drivers/spi/spi-realtek.c + REALTEK WIRELESS DRIVER (rtlwifi family) M: Ping-Ke Shih L: linux-wireless@vger.kernel.org diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index aadaea052f51..058ed1b19bc6 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -646,6 +646,13 @@ config SPI_RB4XX help SPI controller driver for the Mikrotik RB4xx series boards. +config SPI_REALTEK + bool "Realtek SPI controller" + depends on MACH_REALTEK + help + This driver supports the SPI controller used for the bootflash + in the Realtek RTL83xx series SoCs. + config SPI_RPCIF tristate "Renesas RPC-IF SPI driver" depends on RENESAS_RPCIF diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 6fea5821662e..6e9612b70555 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -94,6 +94,7 @@ obj-$(CONFIG_SPI_QCOM_QSPI) += spi-qcom-qspi.o obj-$(CONFIG_SPI_QUP) += spi-qup.o obj-$(CONFIG_SPI_ROCKCHIP) += spi-rockchip.o obj-$(CONFIG_SPI_RB4XX) += spi-rb4xx.o +obj-$(CONFIG_SPI_REALTEK) += spi-realtek.o obj-$(CONFIG_SPI_RPCIF) += spi-rpc-if.o obj-$(CONFIG_SPI_RSPI) += spi-rspi.o obj-$(CONFIG_SPI_S3C24XX) += spi-s3c24xx-hw.o diff --git a/drivers/spi/spi-realtek.c b/drivers/spi/spi-realtek.c new file mode 100644 index 000000000000..d425d36f022f --- /dev/null +++ b/drivers/spi/spi-realtek.c @@ -0,0 +1,215 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include +#include +#include + +struct rtspi { + void __iomem *base; +}; + +/* SPI Flash Configuration Register */ +#define RTL8380_SPI_SFCR 0x00 +#define RTL8380_SPI_SFCR_RBO BIT(28) +#define RTL8380_SPI_SFCR_WBO BIT(27) + +/* SPI Flash Control and Status Register */ +#define RTL8380_SPI_SFCSR 0x08 +#define RTL8380_SPI_SFCSR_CSB0 BIT(31) +#define RTL8380_SPI_SFCSR_CSB1 BIT(30) +#define RTL8380_SPI_SFCSR_RDY BIT(27) +#define RTL8380_SPI_SFCSR_CS BIT(24) +#define RTL8380_SPI_SFCSR_LEN_MASK ~(0x03 << 28) +#define RTL8380_SPI_SFCSR_LEN1 (0x00 << 28) +#define RTL8380_SPI_SFCSR_LEN4 (0x03 << 28) + +/* SPI Flash Data Registers */ +#define RTL8380_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(RTL8380_SPI_SFCSR)); + if (active) + value |= RTL8380_SPI_SFCSR_CSB0; + else + value &= ~RTL8380_SPI_SFCSR_CSB0; + writel(value, REG(RTL8380_SPI_SFCSR)); +} + +static void set_size(struct rtspi *rtspi, int size) +{ + u32 value; + + value = readl(REG(RTL8380_SPI_SFCSR)); + value &= RTL8380_SPI_SFCSR_LEN_MASK; + if (size == 4) + value |= RTL8380_SPI_SFCSR_LEN4; + else if (size == 1) + value |= RTL8380_SPI_SFCSR_LEN1; + writel(value, REG(RTL8380_SPI_SFCSR)); +} + +static inline void wait_ready(struct rtspi *rtspi) +{ + while (!(readl(REG(RTL8380_SPI_SFCSR)) & RTL8380_SPI_SFCSR_RDY)) + ; +} +static void send4(struct rtspi *rtspi, const u32 *buf) +{ + wait_ready(rtspi); + set_size(rtspi, 4); + writel(*buf, REG(RTL8380_SPI_SFDR)); +} + +static void send1(struct rtspi *rtspi, const u8 *buf) +{ + wait_ready(rtspi); + set_size(rtspi, 1); + writel(buf[0] << 24, REG(RTL8380_SPI_SFDR)); +} + +static void rcv4(struct rtspi *rtspi, u32 *buf) +{ + wait_ready(rtspi); + set_size(rtspi, 4); + *buf = readl(REG(RTL8380_SPI_SFDR)); +} + +static void rcv1(struct rtspi *rtspi, u8 *buf) +{ + wait_ready(rtspi); + set_size(rtspi, 1); + *buf = readl(REG(RTL8380_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(RTL8380_SPI_SFCR)); + value |= RTL8380_SPI_SFCR_RBO | RTL8380_SPI_SFCR_WBO; + writel(value, REG(RTL8380_SPI_SFCR)); + + value = readl(REG(RTL8380_SPI_SFCSR)); + /* Permanently disable CS1, since it's never used */ + value |= RTL8380_SPI_SFCSR_CSB1; + /* Select CS0 for use */ + value &= RTL8380_SPI_SFCSR_CS; + writel(value, REG(RTL8380_SPI_SFCSR)); +} + +static int realtek_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 int realtek_spi_remove(struct platform_device *pdev) +{ + struct spi_controller *ctrl = platform_get_drvdata(pdev); + + spi_unregister_controller(ctrl); + + return 0; +} + + +static const struct of_device_id realtek_spi_of_ids[] = { + { .compatible = "realtek,spi" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, realtek_spi_of_ids); + +static struct platform_driver realtek_spi_driver = { + .probe = realtek_spi_probe, + .remove = realtek_spi_remove, + .driver = { + .name = "spi-realtek", + .of_match_table = realtek_spi_of_ids, + }, +}; + +module_platform_driver(realtek_spi_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Bert Vermeulen "); +MODULE_DESCRIPTION("Realtek SPI driver");