From patchwork Thu Aug 4 21:09:29 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 9264263 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 796886048F for ; Thu, 4 Aug 2016 21:10:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 65D51276AE for ; Thu, 4 Aug 2016 21:10:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 55FA92841C; Thu, 4 Aug 2016 21:10:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 61467276AE for ; Thu, 4 Aug 2016 21:10:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965992AbcHDVJj (ORCPT ); Thu, 4 Aug 2016 17:09:39 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:51488 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934031AbcHDVJh (ORCPT ); Thu, 4 Aug 2016 17:09:37 -0400 Received: from debutante.sirena.org.uk ([2a01:348:6:8808:fab::3] helo=debutante) by mezzanine.sirena.org.uk with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1bVPtU-0003pC-HS; Thu, 04 Aug 2016 21:09:34 +0000 Received: from broonie by debutante with local (Exim 4.87) (envelope-from ) id 1bVPtR-0007N8-Kf; Thu, 04 Aug 2016 22:09:29 +0100 From: Mark Brown To: Rich Felker Cc: Mark Brown , linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sh@vger.kernel.org, Mark Brown , Rob Herring , Mark Rutland In-Reply-To: Message-Id: Date: Thu, 04 Aug 2016 22:09:29 +0100 X-SA-Exim-Connect-IP: 2a01:348:6:8808:fab::3 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Applied "spi: add driver for J-Core SPI controller" to the spi tree X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: No (on mezzanine.sirena.org.uk); Unknown failure Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The patch spi: add driver for J-Core SPI controller has been applied to the spi tree at git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark From 711e5a5a28a0ce47c1b8ad54f0abda5c651e6c7b Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 4 Aug 2016 04:30:37 +0000 Subject: [PATCH] spi: add driver for J-Core SPI controller The J-Core "spi2" device is a PIO-based SPI master controller. It differs from "bitbang" devices in that that it's clocked in hardware rather than via soft clock modulation over gpio, and performs byte-at-a-time transfers between the cpu and SPI controller. This driver will be extended to support future versions of the J-Core SPI controller with DMA transfers when they become available. Signed-off-by: Rich Felker Signed-off-by: Mark Brown --- drivers/spi/Kconfig | 7 ++ drivers/spi/Makefile | 1 + drivers/spi/spi-jcore.c | 232 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 240 insertions(+) create mode 100644 drivers/spi/spi-jcore.c diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index d6fb8d4b7786..1abb3d767390 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -285,6 +285,13 @@ config SPI_IMX This enables using the Freescale i.MX SPI controllers in master mode. +config SPI_JCORE + tristate "J-Core SPI Master" + depends on OF && (SUPERH || COMPILE_TEST) + help + This enables support for the SPI master controller in the J-Core + synthesizable, open source SoC. + config SPI_LM70_LLP tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)" depends on PARPORT diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 185367ef6576..8715fec8cffa 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -46,6 +46,7 @@ obj-$(CONFIG_SPI_FSL_SPI) += spi-fsl-spi.o obj-$(CONFIG_SPI_GPIO) += spi-gpio.o obj-$(CONFIG_SPI_IMG_SPFI) += spi-img-spfi.o obj-$(CONFIG_SPI_IMX) += spi-imx.o +obj-$(CONFIG_SPI_JCORE) += spi-jcore.o obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o obj-$(CONFIG_SPI_LP8841_RTC) += spi-lp8841-rtc.o obj-$(CONFIG_SPI_MESON_SPIFC) += spi-meson-spifc.o diff --git a/drivers/spi/spi-jcore.c b/drivers/spi/spi-jcore.c new file mode 100644 index 000000000000..7d2044a106a2 --- /dev/null +++ b/drivers/spi/spi-jcore.c @@ -0,0 +1,232 @@ +/* + * J-Core SPI controller driver + * + * Copyright (C) 2012-2016 Smart Energy Instruments, Inc. + * + * Current version by Rich Felker + * Based loosely on initial version by Oleksandr G Zhadan + * + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "jcore_spi" + +#define CTRL_REG 0x0 +#define DATA_REG 0x4 + +#define JCORE_SPI_CTRL_XMIT 0x02 +#define JCORE_SPI_STAT_BUSY 0x02 +#define JCORE_SPI_CTRL_LOOP 0x08 +#define JCORE_SPI_CTRL_CS_BITS 0x15 + +#define JCORE_SPI_WAIT_RDY_MAX_LOOP 2000000 + +struct jcore_spi { + struct spi_master *master; + void __iomem *base; + unsigned int cs_reg; + unsigned int speed_reg; + unsigned int speed_hz; + unsigned int clock_freq; +}; + +static int jcore_spi_wait(void __iomem *ctrl_reg) +{ + unsigned timeout = JCORE_SPI_WAIT_RDY_MAX_LOOP; + + do { + if (!(readl(ctrl_reg) & JCORE_SPI_STAT_BUSY)) + return 0; + cpu_relax(); + } while (--timeout); + + return -EBUSY; +} + +static void jcore_spi_program(struct jcore_spi *hw) +{ + void __iomem *ctrl_reg = hw->base + CTRL_REG; + + if (jcore_spi_wait(ctrl_reg)) + dev_err(hw->master->dev.parent, + "timeout waiting to program ctrl reg.\n"); + + writel(hw->cs_reg | hw->speed_reg, ctrl_reg); +} + +static void jcore_spi_chipsel(struct spi_device *spi, bool value) +{ + struct jcore_spi *hw = spi_master_get_devdata(spi->master); + u32 csbit = 1U << (2 * spi->chip_select); + + dev_dbg(hw->master->dev.parent, "chipselect %d\n", spi->chip_select); + + if (value) + hw->cs_reg |= csbit; + else + hw->cs_reg &= ~csbit; + + jcore_spi_program(hw); +} + +static void jcore_spi_baudrate(struct jcore_spi *hw, int speed) +{ + if (speed == hw->speed_hz) return; + hw->speed_hz = speed; + if (speed >= hw->clock_freq / 2) + hw->speed_reg = 0; + else + hw->speed_reg = ((hw->clock_freq / 2 / speed) - 1) << 27; + jcore_spi_program(hw); + dev_dbg(hw->master->dev.parent, "speed=%d reg=0x%x\n", + speed, hw->speed_reg); +} + +static int jcore_spi_txrx(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *t) +{ + struct jcore_spi *hw = spi_master_get_devdata(master); + + void __iomem *ctrl_reg = hw->base + CTRL_REG; + void __iomem *data_reg = hw->base + DATA_REG; + u32 xmit; + + /* data buffers */ + const unsigned char *tx; + unsigned char *rx; + unsigned int len; + unsigned int count; + + jcore_spi_baudrate(hw, t->speed_hz); + + xmit = hw->cs_reg | hw->speed_reg | JCORE_SPI_CTRL_XMIT; + tx = t->tx_buf; + rx = t->rx_buf; + len = t->len; + + for (count = 0; count < len; count++) { + if (jcore_spi_wait(ctrl_reg)) + break; + + writel(tx ? *tx++ : 0, data_reg); + writel(xmit, ctrl_reg); + + if (jcore_spi_wait(ctrl_reg)) + break; + + if (rx) + *rx++ = readl(data_reg); + } + + spi_finalize_current_transfer(master); + + if (count < len) + return -EREMOTEIO; + + return 0; +} + +static int jcore_spi_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + struct jcore_spi *hw; + struct spi_master *master; + struct resource *res; + u32 clock_freq; + struct clk *clk; + int err = -ENODEV; + + master = spi_alloc_master(&pdev->dev, sizeof(struct jcore_spi)); + if (!master) + return err; + + /* Setup the master state. */ + master->num_chipselect = 3; + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + master->transfer_one = jcore_spi_txrx; + master->set_cs = jcore_spi_chipsel; + master->dev.of_node = node; + master->bus_num = pdev->id; + + hw = spi_master_get_devdata(master); + hw->master = master; + platform_set_drvdata(pdev, hw); + + /* Find and map our resources */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + goto exit_busy; + if (!devm_request_mem_region(&pdev->dev, res->start, + resource_size(res), pdev->name)) + goto exit_busy; + hw->base = devm_ioremap_nocache(&pdev->dev, res->start, + resource_size(res)); + if (!hw->base) + goto exit_busy; + + /* + * The SPI clock rate controlled via a configurable clock divider + * which is applied to the reference clock. A 50 MHz reference is + * most suitable for obtaining standard SPI clock rates, but some + * designs may have a different reference clock, and the DT must + * make the driver aware so that it can properly program the + * requested rate. If the clock is omitted, 50 MHz is assumed. + */ + clock_freq = 50000000; + clk = devm_clk_get(&pdev->dev, "ref_clk"); + if (!IS_ERR_OR_NULL(clk)) { + if (clk_enable(clk) == 0) + clock_freq = clk_get_rate(clk); + else + dev_warn(&pdev->dev, "could not enable ref_clk\n"); + } + hw->clock_freq = clock_freq; + + /* Initialize all CS bits to high. */ + hw->cs_reg = JCORE_SPI_CTRL_CS_BITS; + jcore_spi_baudrate(hw, 400000); + + /* Register our spi controller */ + err = devm_spi_register_master(&pdev->dev, master); + if (err) + goto exit; + + return 0; + +exit_busy: + err = -EBUSY; +exit: + platform_set_drvdata(pdev, NULL); + spi_master_put(master); + return err; +} + +static const struct of_device_id jcore_spi_of_match[] = { + { .compatible = "jcore,spi2" }, + {}, +}; + +static struct platform_driver jcore_spi_driver = { + .probe = jcore_spi_probe, + .driver = { + .name = DRV_NAME, + .of_match_table = jcore_spi_of_match, + }, +}; + +module_platform_driver(jcore_spi_driver); + +MODULE_DESCRIPTION("J-Core SPI driver"); +MODULE_AUTHOR("Rich Felker "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME);