From patchwork Tue Jun 2 16:57:19 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cyrille Pitchen X-Patchwork-Id: 6529901 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8E4C4C0020 for ; Tue, 2 Jun 2015 17:00:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8751E2055A for ; Tue, 2 Jun 2015 17:00:41 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D593520557 for ; Tue, 2 Jun 2015 17:00:35 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YzpW6-00028v-9y; Tue, 02 Jun 2015 16:58:18 +0000 Received: from eusmtp01.atmel.com ([212.144.249.242]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YzpVy-0001xJ-Qt for linux-arm-kernel@lists.infradead.org; Tue, 02 Jun 2015 16:58:12 +0000 Received: from tenerife.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.30) with Microsoft SMTP Server id 14.3.235.1; Tue, 2 Jun 2015 18:57:46 +0200 From: Cyrille Pitchen To: , , , Subject: [PATCH v2 2/2] clk: at91: add Flexcom clock Date: Tue, 2 Jun 2015 18:57:19 +0200 Message-ID: <62cb26952d0688c6f37ad84d253d5302818a20ae.1433264017.git.cyrille.pitchen@atmel.com> X-Mailer: git-send-email 1.8.2.2 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150602_095811_271913_0CAC1486 X-CRM114-Status: GOOD ( 15.99 ) X-Spam-Score: -2.3 (--) Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, pawel.moll@arm.com, ijc+devicetree@hellion.org.uk, linux-kernel@vger.kernel.org, robh+dt@kernel.org, galak@codeaurora.org, Cyrille Pitchen , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This driver supports the new Atmel Flexcom. The Flexcom is a wrapper which integrates one SPI controller, one I2C controller and one USART. Only one function can be enabled at a time. This driver selects the function once for all, when the Flexcom is probed, according to the value of the new "atmel,flexcom-mode" device tree property. This driver has chosen to present the Flexcom to the system as a clock so the implementation is seamless for the existing Atmel SPI, I2C and USART drivers. Also the Flexcom embeds FIFOs: the latest patches of the SPI, I2C and USART drivers take advantage of this new feature. Signed-off-by: Cyrille Pitchen --- arch/arm/mach-at91/Kconfig | 3 + drivers/clk/at91/Makefile | 1 + drivers/clk/at91/clk-flexcom.c | 160 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 164 insertions(+) create mode 100644 drivers/clk/at91/clk-flexcom.c diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig index fd95f34..8ce9b73 100644 --- a/arch/arm/mach-at91/Kconfig +++ b/arch/arm/mach-at91/Kconfig @@ -90,6 +90,9 @@ config HAVE_AT91_SMD config HAVE_AT91_H32MX bool +config HAVE_AT91_FLEXCOM + bool + config SOC_SAM_V4_V5 bool diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index 89a48a7..74711b8 100644 --- a/drivers/clk/at91/Makefile +++ b/drivers/clk/at91/Makefile @@ -10,3 +10,4 @@ obj-$(CONFIG_HAVE_AT91_UTMI) += clk-utmi.o obj-$(CONFIG_HAVE_AT91_USB_CLK) += clk-usb.o obj-$(CONFIG_HAVE_AT91_SMD) += clk-smd.o obj-$(CONFIG_HAVE_AT91_H32MX) += clk-h32mx.o +obj-$(CONFIG_HAVE_AT91_FLEXCOM) += clk-flexcom.o diff --git a/drivers/clk/at91/clk-flexcom.c b/drivers/clk/at91/clk-flexcom.c new file mode 100644 index 0000000..ce39093 --- /dev/null +++ b/drivers/clk/at91/clk-flexcom.c @@ -0,0 +1,160 @@ +/* + * Driver for Atmel AT91 Flexcom + * + * Copyright (C) 2014 Atmel Corporation + * + * Author: Cyrille Pitchen + * + * Based on drivers/clk/clk-axi-clkgen.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include +#include +#include +#include + + +#define FX_MR 0x0 +#define FX_RHR 0x10 +#define FX_THR 0x20 +#define FX_VERSION 0xfc + +#define FX_MR_NO_COM 0 +#define FX_MR_USART 1 +#define FX_MR_SPI 2 +#define FX_MR_TWI 3 + +struct clk_flexcom { + struct clk_hw hw; + struct device *dev; + u8 __iomem *base; + u32 mr; + bool show_once; +}; + +#define to_clk_flexcom(_hw) container_of(_hw, struct clk_flexcom, hw) + + +static int at91_flexcom_enable(struct clk_hw *hw) +{ + struct clk_flexcom *dev = to_clk_flexcom(hw); + u32 version; + + if (!dev->show_once) { + dev->show_once = true; + version = __raw_readl(dev->base + FX_VERSION); + dev_info(dev->dev, "version: %#x\n", version); + } + + __raw_writel(dev->mr, dev->base + FX_MR); + return 0; +} + +static void at91_flexcom_disable(struct clk_hw *hw) +{ + struct clk_flexcom *dev = to_clk_flexcom(hw); + + __raw_writel(FX_MR_NO_COM, dev->base + FX_MR); +} + +static const struct clk_ops at91_flexcom_ops = { + .enable = at91_flexcom_enable, + .disable = at91_flexcom_disable, +}; + +static int at91_flexcom_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct clk_flexcom *dev; + struct resource *mem; + const char *parent_name, *clk_name, *mode; + struct clk *clk; + struct clk_init_data init; + u32 mr = FX_MR_NO_COM; + int err; + + if (!np) + return -ENODEV; + + err = of_property_read_string(np, "atmel,flexcom-mode", &mode); + if (err) + return err; + + if (!strcmp(mode, "usart")) + mr = FX_MR_USART; + else if (!strcmp(mode, "spi")) + mr = FX_MR_SPI; + else if (!strcmp(mode, "twi") || !strcmp(mode, "i2c")) + mr = FX_MR_TWI; + else + return -EINVAL; + + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dev->base = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(dev->base)) + return PTR_ERR(dev->base); + + parent_name = of_clk_get_parent_name(np, 0); + if (!parent_name) + return -EINVAL; + + clk_name = np->name; + of_property_read_string(np, "clock-output-names", &clk_name); + + init.name = clk_name; + init.ops = &at91_flexcom_ops; + init.flags = 0; + init.parent_names = &parent_name; + init.num_parents = 1; + + dev->hw.init = &init; + dev->dev = &pdev->dev; + dev->mr = mr; + platform_set_drvdata(pdev, dev); + + clk = devm_clk_register(&pdev->dev, &dev->hw); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + return of_clk_add_provider(np, of_clk_src_simple_get, clk); +} + +static int at91_flexcom_remove(struct platform_device *pdev) +{ + of_clk_del_provider(pdev->dev.of_node); + + return 0; +} + +static const struct of_device_id at91_flexcom_dt_ids[] = { + { .compatible = "atmel,sama5d2-flexcom" }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, at91_flexcom_dt_ids); + +static struct platform_driver at91_flexcom_driver = { + .driver = { + .name = "at91_flexcom", + .of_match_table = of_match_ptr(at91_flexcom_dt_ids), + }, + .probe = at91_flexcom_probe, + .remove = at91_flexcom_remove, +}; +module_platform_driver(at91_flexcom_driver); + +MODULE_ALIAS("platform:at91_flexcom"); +MODULE_DESCRIPTION("Atmel AT91 Flexcom driver"); +MODULE_AUTHOR("Cyrille Pitchen "); +MODULE_LICENSE("GPL v2"); +