From patchwork Sat Sep 21 19:19:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Dunn X-Patchwork-Id: 2922951 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id EF9B29F1E2 for ; Sat, 21 Sep 2013 19:21:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D55C1204A7 for ; Sat, 21 Sep 2013 19:21:08 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 922012037A for ; Sat, 21 Sep 2013 19:21:07 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VNSjX-0000GW-EZ; Sat, 21 Sep 2013 19:20:47 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VNSjR-0005lL-C9; Sat, 21 Sep 2013 19:20:41 +0000 Received: from smtp.newsguy.com ([74.209.136.69]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VNSjE-0005id-JN for linux-arm-kernel@lists.infradead.org; Sat, 21 Sep 2013 19:20:29 +0000 Received: from localhost.localdomain (34.sub-70-199-130.myvzw.com [70.199.130.34]) by smtp.newsguy.com (8.14.3/8.14.3) with ESMTP id r8LJJb0L019043 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 21 Sep 2013 12:19:42 -0700 (PDT) (envelope-from mikedunn@newsguy.com) From: Mike Dunn To: linux-pwm@vger.kernel.org Subject: [PATCH RESEND v5 1/2] PWM: PXA: add device tree support to PWM driver Date: Sat, 21 Sep 2013 12:19:33 -0700 Message-Id: <1379791174-2369-2-git-send-email-mikedunn@newsguy.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1379791174-2369-1-git-send-email-mikedunn@newsguy.com> References: <1379791174-2369-1-git-send-email-mikedunn@newsguy.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130921_152028_761671_EFC7D688 X-CRM114-Status: GOOD ( 19.64 ) X-Spam-Score: 0.8 (/) Cc: Marek Vasut , devicetree@vger.kernel.org, Mike Dunn , Pawel Moll , Sergei Shtylyov , Stephen Warren , Dmitry Torokhov , Rob Herring , Chao Xie , Thierry Reding , Haojian Zhuang , Grant Likely , Mark Rutland , Robert Jarzmik , linux-arm-kernel@lists.infradead.org, Ian Campbell X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.5 required=5.0 tests=BAYES_00,KHOP_BIG_TO_CC, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=no 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 patch adds device tree support to the PXA's PWM driver. Nothing needs to be extracted from the device tree node by the PWM device. Client devices need only specify the period; the per-chip index is implicitly zero because one device node must be present for each PWM output in use. This approach is more convenient due to the wide variability in the number of PWM channels present across the various PXA variants, and is made possible by the fact that the register sets for each PWM channel are segregated from each other. An of_xlate() method is added to parse this single-cell node. The existing ID table is reused for the match table data. Tested on a Palm Treo 680 (both platform data and DT cases). Signed-off-by: Mike Dunn Acked-by: Haojian Zhuang --- Documentation/devicetree/bindings/pwm/pxa-pwm.txt | 30 +++++++++++++ drivers/pwm/pwm-pxa.c | 52 ++++++++++++++++++++++- 2 files changed, 81 insertions(+), 1 deletion(-) create mode 100644 Documentation/devicetree/bindings/pwm/pxa-pwm.txt diff --git a/Documentation/devicetree/bindings/pwm/pxa-pwm.txt b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt new file mode 100644 index 0000000..5ae9f1e --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pxa-pwm.txt @@ -0,0 +1,30 @@ +Marvell PWM controller + +Required properties: +- compatible: should be one or more of: + - "marvell,pxa250-pwm" + - "marvell,pxa270-pwm" + - "marvell,pxa168-pwm" + - "marvell,pxa910-pwm" +- reg: Physical base address and length of the registers used by the PWM channel + Note that one device instance must be created for each PWM that is used, so the + length covers only the register window for one PWM output, not that of the + entire PWM controller. Currently length is 0x10 for all supported devices. +- #pwm-cells: Should be 1. This cell is used to specify the period in + nanoseconds. + +Example PWM device node: + +pwm0: pwm@40b00000 { + compatible = "marvell,pxa250-pwm"; + reg = <0x40b00000 0x10>; + #pwm-cells = <1>; +}; + +Example PWM client node: + +backlight { + compatible = "pwm-backlight"; + pwms = <&pwm0 5000000>; + ... +} diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c index a4d2164..e928cc8 100644 --- a/drivers/pwm/pwm-pxa.c +++ b/drivers/pwm/pwm-pxa.c @@ -19,6 +19,7 @@ #include #include #include +#include #include @@ -124,6 +125,45 @@ static struct pwm_ops pxa_pwm_ops = { .owner = THIS_MODULE, }; +#ifdef CONFIG_OF +/* + * Device tree users must create one device instance for each pwm channel. + * Hence we dispense with the HAS_SECONDARY_PWM and "tell" the original driver + * code that this is a single channel pxa25x-pwm. Currently all devices are + * supported identically. + */ +static struct of_device_id pwm_of_match[] = { + { .compatible = "marvell,pxa250-pwm", .data = &pwm_id_table[0]}, + { .compatible = "marvell,pxa270-pwm", .data = &pwm_id_table[0]}, + { .compatible = "marvell,pxa168-pwm", .data = &pwm_id_table[0]}, + { .compatible = "marvell,pxa910-pwm", .data = &pwm_id_table[0]}, + { } +}; +MODULE_DEVICE_TABLE(of, pwm_of_match); +#else +static struct of_device_id *pwm_of_match; +#endif + +static const struct platform_device_id *pxa_pwm_get_id_dt(struct device *dev) +{ + const struct of_device_id *id = of_match_device(pwm_of_match, dev); + return id ? id->data : NULL; +} + +static struct pwm_device * +pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) +{ + struct pwm_device *pwm; + + pwm = pwm_request_from_chip(pc, 0, NULL); + if (IS_ERR(pwm)) + return pwm; + + pwm_set_period(pwm, args->args[0]); + + return pwm; +} + static int pwm_probe(struct platform_device *pdev) { const struct platform_device_id *id = platform_get_device_id(pdev); @@ -131,6 +171,12 @@ static int pwm_probe(struct platform_device *pdev) struct resource *r; int ret = 0; + if (IS_ENABLED(CONFIG_OF) && id == NULL) + id = pxa_pwm_get_id_dt(&pdev->dev); + + if (id == NULL) + return -EINVAL; + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); if (pwm == NULL) { dev_err(&pdev->dev, "failed to allocate memory\n"); @@ -145,7 +191,10 @@ static int pwm_probe(struct platform_device *pdev) pwm->chip.ops = &pxa_pwm_ops; pwm->chip.base = -1; pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1; - + if (IS_ENABLED(CONFIG_OF)) { + pwm->chip.of_xlate = pxa_pwm_of_xlate; + pwm->chip.of_pwm_n_cells = 1; + } r = platform_get_resource(pdev, IORESOURCE_MEM, 0); pwm->mmio_base = devm_ioremap_resource(&pdev->dev, r); if (IS_ERR(pwm->mmio_base)) @@ -176,6 +225,7 @@ static struct platform_driver pwm_driver = { .driver = { .name = "pxa25x-pwm", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(pwm_of_match), }, .probe = pwm_probe, .remove = pwm_remove,