From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Mallon Subject: Re: [PATCH 1/3] rtc: rtc-m48t86: add devicetree bindings Date: Tue, 02 Apr 2013 09:06:47 +1100 Message-ID: <515A04F7.8000904@gmail.com> References: <1364766971-5914-1-git-send-email-alex@digriz.org.uk> <1364766971-5914-2-git-send-email-alex@digriz.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1364766971-5914-2-git-send-email-alex-L4GPcECwBoDe9xe1eoZjHA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Alexander Clouter Cc: Alessandro Zummo , Jason Cooper , rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Rob Herring , Hartley Sweeten , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On 01/04/13 08:56, Alexander Clouter wrote: > This patch allows rtc-m48t86 to be used via devicetree. > > Signed-off-by: Alexander Clouter > --- > .../devicetree/bindings/rtc/rtc-m48t86.txt | 17 ++ > drivers/rtc/rtc-m48t86.c | 254 +++++++++++++++----- > include/linux/m48t86.h | 16 -- > 3 files changed, 213 insertions(+), 74 deletions(-) > create mode 100644 Documentation/devicetree/bindings/rtc/rtc-m48t86.txt > delete mode 100644 include/linux/m48t86.h Some comments below. > diff --git a/Documentation/devicetree/bindings/rtc/rtc-m48t86.txt b/Documentation/devicetree/bindings/rtc/rtc-m48t86.txt > new file mode 100644 > index 0000000..1336c98 > --- /dev/null > +++ b/Documentation/devicetree/bindings/rtc/rtc-m48t86.txt > @@ -0,0 +1,17 @@ > +ST M48T86 / Dallas DS12887 RTC driver > + > +Required properties: > +- compatible: "rtc-m48t86" > +- reg: array of two address ranges of the RTC index and data registers > +- reg-names: must have "rtc_index" and "rtc_data" present > + > +Example: > + > +rtc@808 { > + #address-cells = <1>; > + #size-cells = <1>; > + compatible = "rtc-m48t86"; > + reg = <0x808 0x04>, > + <0x80c 0x04>; > + reg-names = "rtc_index", "rtc_data"; > +}; > diff --git a/drivers/rtc/rtc-m48t86.c b/drivers/rtc/rtc-m48t86.c > index 2ffbcac..47e9fd1 100644 > --- a/drivers/rtc/rtc-m48t86.c > +++ b/drivers/rtc/rtc-m48t86.c > @@ -16,8 +16,10 @@ > #include > #include > #include > -#include > #include > +#include > +#include > +#include > > #define M48T86_REG_SEC 0x00 > #define M48T86_REG_SECALRM 0x01 > @@ -41,40 +43,61 @@ > > #define DRV_VERSION "0.1" > > +struct m48t86_rtc_private_data { > + void __iomem *io_index; > + void __iomem *io_data; > + > + struct rtc_device *rtc; > +}; > + > +static unsigned char m48t86_rtc_readbyte( > + struct m48t86_rtc_private_data *priv, > + unsigned long addr) Line breaks like this are a bit ugly. Breaking after the return type would be better. You can shorten this by changing 'unsigned char' to 'u8', and 'm48t86_rtc_private_data' to something like 'm48t86_priv'. Why is addr unsigned long if you are passing it to writeb? > +{ > + writeb(addr, priv->io_index); > + return readb(priv->io_data); > +} > + > +static void m48t86_rtc_writebyte( > + struct m48t86_rtc_private_data *priv, > + unsigned char value, unsigned long addr) > +{ > + writeb(addr, priv->io_index); > + writeb(value, priv->io_data); > +} > > static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm) > { > unsigned char reg; > - struct platform_device *pdev = to_platform_device(dev); > - struct m48t86_ops *ops = pdev->dev.platform_data; > + struct m48t86_rtc_private_data *priv = dev_get_drvdata(dev); > > - reg = ops->readbyte(M48T86_REG_B); > + reg = m48t86_rtc_readbyte(priv, M48T86_REG_B); > > if (reg & M48T86_REG_B_DM) { > /* data (binary) mode */ > - tm->tm_sec = ops->readbyte(M48T86_REG_SEC); > - tm->tm_min = ops->readbyte(M48T86_REG_MIN); > - tm->tm_hour = ops->readbyte(M48T86_REG_HOUR) & 0x3F; > - tm->tm_mday = ops->readbyte(M48T86_REG_DOM); > + tm->tm_sec = m48t86_rtc_readbyte(priv, M48T86_REG_SEC); > + tm->tm_min = m48t86_rtc_readbyte(priv, M48T86_REG_MIN); > + tm->tm_hour = m48t86_rtc_readbyte(priv, M48T86_REG_HOUR) & 0x3F; > + tm->tm_mday = m48t86_rtc_readbyte(priv, M48T86_REG_DOM); > /* tm_mon is 0-11 */ > - tm->tm_mon = ops->readbyte(M48T86_REG_MONTH) - 1; > - tm->tm_year = ops->readbyte(M48T86_REG_YEAR) + 100; > - tm->tm_wday = ops->readbyte(M48T86_REG_DOW); > + tm->tm_mon = m48t86_rtc_readbyte(priv, M48T86_REG_MONTH) - 1; > + tm->tm_year = m48t86_rtc_readbyte(priv, M48T86_REG_YEAR) + 100; > + tm->tm_wday = m48t86_rtc_readbyte(priv, M48T86_REG_DOW); > } else { > /* bcd mode */ > - tm->tm_sec = bcd2bin(ops->readbyte(M48T86_REG_SEC)); > - tm->tm_min = bcd2bin(ops->readbyte(M48T86_REG_MIN)); > - tm->tm_hour = bcd2bin(ops->readbyte(M48T86_REG_HOUR) & 0x3F); > - tm->tm_mday = bcd2bin(ops->readbyte(M48T86_REG_DOM)); > + tm->tm_sec = bcd2bin(m48t86_rtc_readbyte(priv, M48T86_REG_SEC)); > + tm->tm_min = bcd2bin(m48t86_rtc_readbyte(priv, M48T86_REG_MIN)); > + tm->tm_hour = bcd2bin(m48t86_rtc_readbyte(priv, M48T86_REG_HOUR) & 0x3F); > + tm->tm_mday = bcd2bin(m48t86_rtc_readbyte(priv, M48T86_REG_DOM)); > /* tm_mon is 0-11 */ > - tm->tm_mon = bcd2bin(ops->readbyte(M48T86_REG_MONTH)) - 1; > - tm->tm_year = bcd2bin(ops->readbyte(M48T86_REG_YEAR)) + 100; > - tm->tm_wday = bcd2bin(ops->readbyte(M48T86_REG_DOW)); > + tm->tm_mon = bcd2bin(m48t86_rtc_readbyte(priv, M48T86_REG_MONTH)) - 1; > + tm->tm_year = bcd2bin(m48t86_rtc_readbyte(priv, M48T86_REG_YEAR)) + 100; > + tm->tm_wday = bcd2bin(m48t86_rtc_readbyte(priv, M48T86_REG_DOW)); > } > > /* correct the hour if the clock is in 12h mode */ > if (!(reg & M48T86_REG_B_H24)) > - if (ops->readbyte(M48T86_REG_HOUR) & 0x80) > + if (m48t86_rtc_readbyte(priv, M48T86_REG_HOUR) & 0x80) > tm->tm_hour += 12; > > return rtc_valid_tm(tm); > @@ -83,38 +106,37 @@ static int m48t86_rtc_read_time(struct device *dev, struct rtc_time *tm) > static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm) > { > unsigned char reg; > - struct platform_device *pdev = to_platform_device(dev); > - struct m48t86_ops *ops = pdev->dev.platform_data; > + struct m48t86_rtc_private_data *priv = dev_get_drvdata(dev); > > - reg = ops->readbyte(M48T86_REG_B); > + reg = m48t86_rtc_readbyte(priv, M48T86_REG_B); > > /* update flag and 24h mode */ > reg |= M48T86_REG_B_SET | M48T86_REG_B_H24; > - ops->writebyte(reg, M48T86_REG_B); > + m48t86_rtc_writebyte(priv, reg, M48T86_REG_B); > > if (reg & M48T86_REG_B_DM) { > /* data (binary) mode */ > - ops->writebyte(tm->tm_sec, M48T86_REG_SEC); > - ops->writebyte(tm->tm_min, M48T86_REG_MIN); > - ops->writebyte(tm->tm_hour, M48T86_REG_HOUR); > - ops->writebyte(tm->tm_mday, M48T86_REG_DOM); > - ops->writebyte(tm->tm_mon + 1, M48T86_REG_MONTH); > - ops->writebyte(tm->tm_year % 100, M48T86_REG_YEAR); > - ops->writebyte(tm->tm_wday, M48T86_REG_DOW); > + m48t86_rtc_writebyte(priv, tm->tm_sec, M48T86_REG_SEC); > + m48t86_rtc_writebyte(priv, tm->tm_min, M48T86_REG_MIN); > + m48t86_rtc_writebyte(priv, tm->tm_hour, M48T86_REG_HOUR); > + m48t86_rtc_writebyte(priv, tm->tm_mday, M48T86_REG_DOM); > + m48t86_rtc_writebyte(priv, tm->tm_mon + 1, M48T86_REG_MONTH); > + m48t86_rtc_writebyte(priv, tm->tm_year % 100, M48T86_REG_YEAR); > + m48t86_rtc_writebyte(priv, tm->tm_wday, M48T86_REG_DOW); > } else { > /* bcd mode */ > - ops->writebyte(bin2bcd(tm->tm_sec), M48T86_REG_SEC); > - ops->writebyte(bin2bcd(tm->tm_min), M48T86_REG_MIN); > - ops->writebyte(bin2bcd(tm->tm_hour), M48T86_REG_HOUR); > - ops->writebyte(bin2bcd(tm->tm_mday), M48T86_REG_DOM); > - ops->writebyte(bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH); > - ops->writebyte(bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR); > - ops->writebyte(bin2bcd(tm->tm_wday), M48T86_REG_DOW); > + m48t86_rtc_writebyte(priv, bin2bcd(tm->tm_sec), M48T86_REG_SEC); > + m48t86_rtc_writebyte(priv, bin2bcd(tm->tm_min), M48T86_REG_MIN); > + m48t86_rtc_writebyte(priv, bin2bcd(tm->tm_hour), M48T86_REG_HOUR); > + m48t86_rtc_writebyte(priv, bin2bcd(tm->tm_mday), M48T86_REG_DOM); > + m48t86_rtc_writebyte(priv, bin2bcd(tm->tm_mon + 1), M48T86_REG_MONTH); > + m48t86_rtc_writebyte(priv, bin2bcd(tm->tm_year % 100), M48T86_REG_YEAR); > + m48t86_rtc_writebyte(priv, bin2bcd(tm->tm_wday), M48T86_REG_DOW); > } > > /* update ended */ > reg &= ~M48T86_REG_B_SET; > - ops->writebyte(reg, M48T86_REG_B); > + m48t86_rtc_writebyte(priv, reg, M48T86_REG_B); > > return 0; > } > @@ -122,15 +144,14 @@ static int m48t86_rtc_set_time(struct device *dev, struct rtc_time *tm) > static int m48t86_rtc_proc(struct device *dev, struct seq_file *seq) > { > unsigned char reg; > - struct platform_device *pdev = to_platform_device(dev); > - struct m48t86_ops *ops = pdev->dev.platform_data; > + struct m48t86_rtc_private_data *priv = dev_get_drvdata(dev); > > - reg = ops->readbyte(M48T86_REG_B); > + reg = m48t86_rtc_readbyte(priv, M48T86_REG_B); > > seq_printf(seq, "mode\t\t: %s\n", > (reg & M48T86_REG_B_DM) ? "binary" : "bcd"); > > - reg = ops->readbyte(M48T86_REG_D); > + reg = m48t86_rtc_readbyte(priv, M48T86_REG_D); > > seq_printf(seq, "battery\t\t: %s\n", > (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted"); > @@ -144,42 +165,159 @@ static const struct rtc_class_ops m48t86_rtc_ops = { > .proc = m48t86_rtc_proc, > }; > > -static int m48t86_rtc_probe(struct platform_device *dev) > +/* > + * The RTC chip has 114 bytes upper bytes that can be used as user storage > + * space which we can use to test if the chip is present; for example it is > + * an optional feature and not all boards will have it present. > + * > + * I've used the method Technologic Systems use in their rtc7800.c example > + * for the detection. > + * > + * TODO: track down a guinea pig without an RTC to see if we can work out a > + * better RTC detection routine > + */ > +static int m48t86_rtc_detect(struct device *dev) > +{ > + struct m48t86_rtc_private_data *priv = dev_get_drvdata(dev); > + > + unsigned char tmp_rtc0, tmp_rtc1; > + > + tmp_rtc0 = m48t86_rtc_readbyte(priv, 126); > + tmp_rtc1 = m48t86_rtc_readbyte(priv, 127); These should probably have #defines, even if it is just something like: #define REG_SCRATCH_1 126 #define REG_SCRATCH_2 127 > + > + m48t86_rtc_writebyte(priv, 0x00, 126); > + m48t86_rtc_writebyte(priv, 0x55, 127); > + if (m48t86_rtc_readbyte(priv, 127) == 0x55) { > + m48t86_rtc_writebyte(priv, 0xaa, 127); > + if (m48t86_rtc_readbyte(priv, 127) == 0xaa > + && m48t86_rtc_readbyte(priv, 126) == 0x00) { > + m48t86_rtc_writebyte(priv, tmp_rtc0, 126); > + m48t86_rtc_writebyte(priv, tmp_rtc1, 127); > + > + return 0; > + } > + } > + > + dev_info(dev, "RTC not found\n"); Don't spam the log with stuff like this. > + return -ENODEV; > +} > + > +static int m48t86_rtc_probe(struct platform_device *pdev) > { > + struct m48t86_rtc_private_data *priv; > + struct resource *res_index, *res_data; > unsigned char reg; > - struct m48t86_ops *ops = dev->dev.platform_data; > - struct rtc_device *rtc = rtc_device_register("m48t86", > - &dev->dev, &m48t86_rtc_ops, THIS_MODULE); > + int err; > + > + res_index = platform_get_resource_byname( > + pdev, IORESOURCE_MEM, "rtc_index"); Nitpick - please break lines like this: res_index = platform_get_resource_byname(pdev, IO_RESOURCE_MEM, "rtc_index"); You can use the double tab stop indent if you want, but please try to fill the 80 columns before wrapping arguments onto the next line. > + if (!res_index) > + return -ENXIO; > + res_data = platform_get_resource_byname( > + pdev, IORESOURCE_MEM, "rtc_data"); > + if (!res_data) > + return -ENXIO; > + > + /* Allocate memory for the device structure (and zero it) */ > + priv = kzalloc(sizeof(struct m48t86_rtc_private_data), GFP_KERNEL); > + if (!priv) { > + dev_err(&pdev->dev, "failed to allocate device structure.\n"); Don't need the warning. kalloc failures will automatically print a warning and stacktrace. > + return -ENOMEM; > + } > + > + if (!request_mem_region(res_index->start, resource_size(res_index), > + dev_name(&pdev->dev))) { > + dev_err(&pdev->dev, "request_mem_region failed\n"); > + err = -EBUSY; > + goto out_free; > + } > + if (!request_mem_region(res_data->start, resource_size(res_data), > + dev_name(&pdev->dev))) { > + dev_err(&pdev->dev, "request_mem_region failed\n"); > + err = -EBUSY; > + goto out_release_io_index; > + } > + > + priv->io_index = ioremap(res_index->start, resource_size(res_index)); > + if (priv->io_index == NULL) { > + dev_err(&pdev->dev, "ioremap failed\n"); > + err = -EIO; > + goto out_release_io_data; > + } > + priv->io_data = ioremap(res_data->start, resource_size(res_data)); > + if (priv->io_data == NULL) { > + dev_err(&pdev->dev, "ioremap failed\n"); > + err = -EIO; > + goto out_ctrl; > + } > + > + platform_set_drvdata(pdev, priv); > > - if (IS_ERR(rtc)) > - return PTR_ERR(rtc); > + err = m48t86_rtc_detect(&pdev->dev); > + if (err) > + goto out; > > - platform_set_drvdata(dev, rtc); > + priv->rtc = rtc_device_register("m48t86", > + &pdev->dev, &m48t86_rtc_ops, THIS_MODULE); > + if (IS_ERR(priv->rtc)) { > + err = PTR_ERR(priv->rtc); > + goto out; > + } > > /* read battery status */ > - reg = ops->readbyte(M48T86_REG_D); > - dev_info(&dev->dev, "battery %s\n", > + reg = m48t86_rtc_readbyte(priv, M48T86_REG_D); > + dev_info(&pdev->dev, "battery %s\n", > (reg & M48T86_REG_D_VRT) ? "ok" : "exhausted"); > > return 0; > + > +out: > + platform_set_drvdata(pdev, NULL); I don't think this is needed. > + iounmap(priv->io_data); > +out_ctrl: > + iounmap(priv->io_index); > +out_release_io_data: > + release_mem_region(res_data->start, resource_size(res_data)); > +out_release_io_index: > + release_mem_region(res_index->start, resource_size(res_index)); > +out_free: > + kfree(priv); > + return err; > } > > -static int m48t86_rtc_remove(struct platform_device *dev) > +static int m48t86_rtc_remove(struct platform_device *pdev) > { > - struct rtc_device *rtc = platform_get_drvdata(dev); > + struct m48t86_rtc_private_data *priv = platform_get_drvdata(pdev); > + struct resource *res; > + > + rtc_device_unregister(priv->rtc); > > - if (rtc) > - rtc_device_unregister(rtc); > + platform_set_drvdata(pdev, NULL); > > - platform_set_drvdata(dev, NULL); > + iounmap(priv->io_data); > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rtc_data"); > + release_mem_region(res->start, resource_size(res)); > + > + iounmap(priv->io_index); > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rtc_index"); > + release_mem_region(res->start, resource_size(res)); > + > + kfree(priv); > > return 0; > } > > +static const struct of_device_id m48t86_rtc_match[] = { > + { .compatible = "rtc-m48t86" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, m48t86_rtc_match); > + > static struct platform_driver m48t86_rtc_platform_driver = { > .driver = { > - .name = "rtc-m48t86", > - .owner = THIS_MODULE, > + .name = "rtc-m48t86", > + .owner = THIS_MODULE, > + .of_match_table = m48t86_rtc_match, > }, > .probe = m48t86_rtc_probe, > .remove = m48t86_rtc_remove, > diff --git a/include/linux/m48t86.h b/include/linux/m48t86.h > deleted file mode 100644 > index 915d6b4..0000000 > --- a/include/linux/m48t86.h > +++ /dev/null > @@ -1,16 +0,0 @@ > -/* > - * ST M48T86 / Dallas DS12887 RTC driver > - * Copyright (c) 2006 Tower Technologies > - * > - * Author: Alessandro Zummo > - * > - * 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. > -*/ > - > -struct m48t86_ops > -{ > - void (*writebyte)(unsigned char value, unsigned long addr); > - unsigned char (*readbyte)(unsigned long addr); > -}; >