Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751517AbbEZGFv (ORCPT ); Tue, 26 May 2015 02:05:51 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:49331 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751390AbbEZGFt (ORCPT ); Tue, 26 May 2015 02:05:49 -0400 Date: Tue, 26 May 2015 08:05:33 +0200 From: Sascha Hauer To: YH Huang Cc: Daniel Kurtz , Mark Rutland , linux-pwm@vger.kernel.org, srv_heupstream@mediatek.com, Pawel Moll , "open list:OPEN FIRMWARE AND..." , "linux-kernel@vger.kernel.org" , Rob Herring , Thierry Reding , linux-mediatek@lists.infradead.org, Sascha Hauer , Matthias Brugger , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH 2/2] pwm: add Mediatek display PWM driver support Message-ID: <20150526060533.GW6325@pengutronix.de> References: <1431336382-13167-1-git-send-email-yh.huang@mediatek.com> <1431336382-13167-3-git-send-email-yh.huang@mediatek.com> <1432196551.15653.2.camel@mtksdaap41> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1432196551.15653.2.camel@mtksdaap41> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 08:04:45 up 70 days, 17:56, 105 users, load average: 0.24, 0.16, 0.15 User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11421 Lines: 280 On Thu, May 21, 2015 at 04:22:31PM +0800, YH Huang wrote: > On Mon, 2015-05-18 at 11:42 +0800, Daniel Kurtz wrote: > > On Mon, May 11, 2015 at 5:26 PM, YH Huang wrote: > > > Add display PWM driver support to modify backlight for MT8173/MT6595. > > > > > > Signed-off-by: YH Huang > > > --- > > > drivers/pwm/Kconfig | 9 ++ > > > drivers/pwm/Makefile | 1 + > > > drivers/pwm/pwm-disp-mediatek.c | 225 ++++++++++++++++++++++++++++++++++++++++ > > > 3 files changed, 235 insertions(+) > > > create mode 100644 drivers/pwm/pwm-disp-mediatek.c > > > > > > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig > > > index b1541f4..9edbb5a 100644 > > > --- a/drivers/pwm/Kconfig > > > +++ b/drivers/pwm/Kconfig > > > @@ -111,6 +111,15 @@ config PWM_CLPS711X > > > To compile this driver as a module, choose M here: the module > > > will be called pwm-clps711x. > > > > > > +config PWM_DISP_MEDIATEK > > > + tristate "MEDIATEK display PWM driver" > > > + depends on OF > > > + help > > > + Generic PWM framework driver for mediatek disp-pwm device. > > > + > > > + To compile this driver as a module, choose M here: the module > > > + will be called pwm-disp-mediatek. > > > + > > > config PWM_EP93XX > > > tristate "Cirrus Logic EP93xx PWM support" > > > depends on ARCH_EP93XX > > > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile > > > index ec50eb5..c5ff72a 100644 > > > --- a/drivers/pwm/Makefile > > > +++ b/drivers/pwm/Makefile > > > @@ -8,6 +8,7 @@ obj-$(CONFIG_PWM_BCM_KONA) += pwm-bcm-kona.o > > > obj-$(CONFIG_PWM_BCM2835) += pwm-bcm2835.o > > > obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o > > > obj-$(CONFIG_PWM_CLPS711X) += pwm-clps711x.o > > > +obj-$(CONFIG_PWM_DISP_MEDIATEK) += pwm-disp-mediatek.o > > > obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o > > > obj-$(CONFIG_PWM_FSL_FTM) += pwm-fsl-ftm.o > > > obj-$(CONFIG_PWM_IMG) += pwm-img.o > > > diff --git a/drivers/pwm/pwm-disp-mediatek.c b/drivers/pwm/pwm-disp-mediatek.c > > > new file mode 100644 > > > index 0000000..38293af > > > --- /dev/null > > > +++ b/drivers/pwm/pwm-disp-mediatek.c > > > @@ -0,0 +1,225 @@ > > > +/* > > > + * Mediatek display pulse-width-modulation controller driver. > > > + * Copyright (c) 2015 MediaTek Inc. > > > + * Author: YH Huang > > > + * > > > + * This program is free software; you can redistribute it and/or modify > > > + * it under the terms of the GNU General Public License version 2 as > > > + * published by the Free Software Foundation. > > > + * > > > + * This program is distributed in the hope that it will be useful, > > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > > + * GNU General Public License for more details. > > > + */ > > > + > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > + > > > +#define DISP_PWM_EN_OFF (0x0) > > > +#define PWM_ENABLE_SHIFT (0x0) > > > +#define PWM_ENABLE_MASK (0x1 << PWM_ENABLE_SHIFT) > > > + > > > +#define DISP_PWM_COMMIT_OFF (0x08) > > > +#define PWM_COMMIT_SHIFT (0x0) > > > +#define PWM_COMMIT_MASK (0x1 << PWM_COMMIT_SHIFT) > > > + > > > +#define DISP_PWM_CON_0_OFF (0x10) > > > +#define PWM_CLKDIV_SHIFT (0x10) > > > +#define PWM_CLKDIV_MASK (0x3ff << PWM_CLKDIV_SHIFT) > > > +#define PWM_CLKDIV_MAX (0x000003ff) > > > + > > > +#define DISP_PWM_CON_1_OFF (0x14) > > > +#define PWM_PERIOD_SHIFT (0x0) > > > +#define PWM_PERIOD_MASK (0xfff << PWM_PERIOD_SHIFT) > > > +#define PWM_PERIOD_MAX (0x00000fff) > > > +/* Shift log2(PWM_PERIOD_MAX + 1) as divisor */ > > > +#define PWM_PERIOD_BIT_SHIFT 12 > > > + > > > +#define PWM_HIGH_WIDTH_SHIFT (0x10) > > > +#define PWM_HIGH_WIDTH_MASK (0x1fff << PWM_HIGH_WIDTH_SHIFT) > > > + > > > +#define NUM_PWM 1 > > > + > > > +struct mtk_disp_pwm_chip { > > > + struct pwm_chip chip; > > > + struct device *dev; > > > + struct clk *clk_main; > > > + struct clk *clk_mm; > > > + void __iomem *mmio_base; > > > +}; > > > + > > > +static void mtk_disp_pwm_setting(void __iomem *address, u32 value, u32 mask) > > > +{ > > > + u32 val; > > > + > > > + val = readl(address); > > > + val &= ~mask; > > > + val |= value; > > > + writel(val, address); > > > +} > > > + > > > +static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > > > + int duty_ns, int period_ns) > > > +{ > > > + struct mtk_disp_pwm_chip *mpc; > > > + u64 div, rate; > > > + u32 clk_div, period, high_width, rem; > > > + > > > + /* > > > + * Find period, high_width and clk_div to suit duty_ns and period_ns. > > > + * Calculate proper div value to keep period value in the bound. > > > + * > > > + * period_ns = 10^9 * (clk_div + 1) * (period +1) / PWM_CLK_RATE > > > + * duty_ns = 10^9 * (clk_div + 1) * (high_width + 1) / PWM_CLK_RATE > > > + * > > > + * period = (PWM_CLK_RATE * period_ns) / (10^9 * (clk_div + 1)) - 1 > > > + * high_width = (PWM_CLK_RATE * duty_ns) / (10^9 * (clk_div + 1)) - 1 > > > + */ > > > + mpc = container_of(chip, struct mtk_disp_pwm_chip, chip); > > > + rate = clk_get_rate(mpc->clk_main); > > > + clk_div = div_u64_rem(rate * period_ns, NSEC_PER_SEC, &rem) >> > > > + PWM_PERIOD_BIT_SHIFT; > > > + if (clk_div > PWM_CLKDIV_MAX) > > > + return -EINVAL; > > > + > > > + div = clk_div + 1; > > > + period = div64_u64(rate * period_ns, NSEC_PER_SEC * div); > > > + if (period > 0) > > > + period--; > > > + high_width = div64_u64(rate * duty_ns, NSEC_PER_SEC * div); > > > + if (high_width > 0) > > > + high_width--; > > > + > > > + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_CON_0_OFF, > > > + clk_div << PWM_CLKDIV_SHIFT, PWM_CLKDIV_MASK); > > > + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_CON_1_OFF, > > > + (period << PWM_PERIOD_SHIFT) | > > > + (high_width << PWM_HIGH_WIDTH_SHIFT), > > > + PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK); > > > + > > > + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_COMMIT_OFF, > > > + 1 << PWM_COMMIT_SHIFT, PWM_COMMIT_MASK); > > > + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_COMMIT_OFF, > > > + 0 << PWM_COMMIT_SHIFT, PWM_COMMIT_MASK); > > > + > > > + return 0; > > > +} > > > + > > > +static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) > > > +{ > > > + struct mtk_disp_pwm_chip *mpc; > > > + > > > + mpc = container_of(chip, struct mtk_disp_pwm_chip, chip); > > > + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_EN_OFF, > > > + 1 << PWM_ENABLE_SHIFT, PWM_ENABLE_MASK); > > > + > > > + return 0; > > > +} > > > + > > > +static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > > +{ > > > + struct mtk_disp_pwm_chip *mpc; > > > + > > > + mpc = container_of(chip, struct mtk_disp_pwm_chip, chip); > > > + mtk_disp_pwm_setting(mpc->mmio_base + DISP_PWM_EN_OFF, > > > + 0 << PWM_ENABLE_SHIFT, PWM_ENABLE_MASK); > > > +} > > > + > > > +static const struct pwm_ops mtk_disp_pwm_ops = { > > > + .config = mtk_disp_pwm_config, > > > + .enable = mtk_disp_pwm_enable, > > > + .disable = mtk_disp_pwm_disable, > > > + .owner = THIS_MODULE, > > > +}; > > > + > > > +static int mtk_disp_pwm_probe(struct platform_device *pdev) > > > +{ > > > + struct mtk_disp_pwm_chip *pwm; > > > + struct resource *r; > > > + int ret; > > > + > > > + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); > > > + if (!pwm) > > > + return -ENOMEM; > > > + > > > + pwm->dev = &pdev->dev; > > > + > > > + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > + pwm->mmio_base = devm_ioremap_resource(&pdev->dev, r); > > > + if (IS_ERR(pwm->mmio_base)) > > > + return PTR_ERR(pwm->mmio_base); > > > + > > > + pwm->clk_main = devm_clk_get(&pdev->dev, "main"); > > > + if (IS_ERR(pwm->clk_main)) > > > + return PTR_ERR(pwm->clk_main); > > > + pwm->clk_mm = devm_clk_get(&pdev->dev, "mm"); > > > + if (IS_ERR(pwm->clk_mm)) > > > + return PTR_ERR(pwm->clk_mm); > > > + > > > + ret = clk_prepare_enable(pwm->clk_main); > > > + if (ret < 0) > > > + return ret; > > > + ret = clk_prepare_enable(pwm->clk_mm); > > > + if (ret < 0) { > > > + clk_disable_unprepare(pwm->clk_main); > > > + return ret; > > > + } > > > + > > > + platform_set_drvdata(pdev, pwm); > > > + > > > + pwm->chip.dev = &pdev->dev; > > > + pwm->chip.ops = &mtk_disp_pwm_ops; > > > + pwm->chip.base = -1; > > > + pwm->chip.npwm = NUM_PWM; > > > + > > > + ret = pwmchip_add(&pwm->chip); > > > + if (ret < 0) { > > > + dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); > > > + return ret; > > > + } > > > + > > > + return 0; > > > +} > > > + > > > +static int mtk_disp_pwm_remove(struct platform_device *pdev) > > > +{ > > > + struct mtk_disp_pwm_chip *pc = platform_get_drvdata(pdev); > > > + > > > + if (WARN_ON(!pc)) > > > + return -ENODEV; > > > + > > > + clk_disable_unprepare(pc->clk_main); > > > + clk_disable_unprepare(pc->clk_mm); > > > + > > > + return pwmchip_remove(&pc->chip); > > > +} > > > + > > > +static const struct of_device_id mtk_disp_pwm_of_match[] = { > > > + { .compatible = "mediatek,mt6595-disp-pwm" }, > > > > Does this driver support the PWM in mt8173? > > If so, don't you need this, too: > > > > { .compatible = "mediatek,mt8173-disp-pwm" }, > > Yes, it supports mt8173. > I will add it. If both yre compatible you don't need to add it since you have a "mediatek,mt6595-disp-pwm" in the mt8173 device tree. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/