From patchwork Fri Jun 3 14:34:07 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shawn Guo X-Patchwork-Id: 1733 Return-Path: Delivered-To: unknown Received: from imap.gmail.com (74.125.159.109) by localhost6.localdomain6 with IMAP4-SSL; 08 Jun 2011 14:55:06 -0000 Delivered-To: patches@linaro.org Received: by 10.52.181.10 with SMTP id ds10cs17671vdc; Fri, 3 Jun 2011 07:31:02 -0700 (PDT) Received: by 10.42.243.3 with SMTP id lk3mr3467562icb.161.1307111461563; Fri, 03 Jun 2011 07:31:01 -0700 (PDT) Received: from VA3EHSOBE007.bigfish.com (va3ehsobe006.messaging.microsoft.com [216.32.180.16]) by mx.google.com with ESMTPS id h10si10333330icx.83.2011.06.03.07.31.00 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 03 Jun 2011 07:31:01 -0700 (PDT) Received-SPF: neutral (google.com: 216.32.180.16 is neither permitted nor denied by best guess record for domain of r65073@freescale.com) client-ip=216.32.180.16; Authentication-Results: mx.google.com; spf=neutral (google.com: 216.32.180.16 is neither permitted nor denied by best guess record for domain of r65073@freescale.com) smtp.mail=r65073@freescale.com Received: from mail140-va3-R.bigfish.com (10.7.14.244) by VA3EHSOBE007.bigfish.com (10.7.40.11) with Microsoft SMTP Server id 14.1.225.22; Fri, 3 Jun 2011 14:30:59 +0000 Received: from mail140-va3 (localhost.localdomain [127.0.0.1]) by mail140-va3-R.bigfish.com (Postfix) with ESMTP id 1E67B998198; Fri, 3 Jun 2011 14:30:58 +0000 (UTC) X-SpamScore: -12 X-BigFish: VS-12(zz936eK1432N98dKzz1202hzz8275dhz2dh2a8h668h839h61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPVD:NLI; H:mail.freescale.net; RD:none; EFVD:NLI Received: from mail140-va3 (localhost.localdomain [127.0.0.1]) by mail140-va3 (MessageSwitch) id 130711135745582_7885; Fri, 3 Jun 2011 14:29:17 +0000 (UTC) Received: from VA3EHSMHS023.bigfish.com (unknown [10.7.14.254]) by mail140-va3.bigfish.com (Postfix) with ESMTP id 2962A110057; Fri, 3 Jun 2011 14:29:16 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by VA3EHSMHS023.bigfish.com (10.7.99.33) with Microsoft SMTP Server (TLS) id 14.1.225.22; Fri, 3 Jun 2011 14:29:08 +0000 Received: from az33smr01.freescale.net (10.64.34.199) by 039-SN1MMR1-003.039d.mgd.msft.net (10.84.1.16) with Microsoft SMTP Server id 14.1.289.8; Fri, 3 Jun 2011 09:29:07 -0500 Received: from S2100-06.ap.freescale.net (S2100-06.ap.freescale.net [10.192.242.125]) by az33smr01.freescale.net (8.13.1/8.13.0) with ESMTP id p53ET135019712; Fri, 3 Jun 2011 09:29:01 -0500 (CDT) Date: Fri, 3 Jun 2011 22:34:07 +0800 From: Shawn Guo To: Russell King - ARM Linux CC: Shawn Guo , , , , , , , Subject: Re: [PATCH v2 0/4] Move plat-mxc gpio driver into drivers/gpio Message-ID: <20110603143406.GA19344@S2100-06.ap.freescale.net> References: <1306985632-18820-1-git-send-email-shawn.guo@linaro.org> <20110603075201.GE10532@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20110603075201.GE10532@n2100.arm.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginatorOrg: freescale.com Hi Russell, On Fri, Jun 03, 2011 at 08:52:01AM +0100, Russell King - ARM Linux wrote: > On Thu, Jun 02, 2011 at 11:33:48AM +0800, Shawn Guo wrote: > > arch/arm/plat-mxc/gpio.c | 361 ------------------- > > drivers/gpio/gpio-mxc.c | 433 +++++++++++++++++++++++ > My bad here. I should have used 'git diff --stat -M' to show the the following. .../arm/plat-mxc/gpio.c => drivers/gpio/gpio-mxc.c | 216 +++++++++++++------- > I'm wondering why just moving this driver into drivers/gpio has > resulted in it growing by 72 lines - and it's not clear from the > diffs why that is because of the way they're broken up. > Yes, I agree. But when I did something like that to ease the review, people think it's not necessary :) http://permalink.gmane.org/gmane.linux.kernel/1143257 > Would it not be better to have the first patch to merely move > arch/arm/plat-mxc/gpio.c to drivers/gpio/gpio-mxc.c, making whatever > config changes are necessary. Then subsequent patches should change > drivers/gpio/gpio-mxc.c as required - which means we can see what > changes are being made. > Yes, I agree this is the best practice. Will do it in the future posts. To answer your question about 72 lines growing, here is what copied from patch #1 commit message. --- quote begins --- Add gpio-mxc driver by copying arch/arm/plat-mxc/gpio.c into drivers/gpio with the following changes. * Use readl/writel to replace mach-specific accessors __raw_readl/__raw_writel * Migrate to platform driver by adding .probe function * Add a list to save all mx2 ports references, so that mx2_gpio_irq_handler can walk through all interrupt status registers --- quote ends --- And the following is what the changes are exactly. --- arch/arm/plat-mxc/gpio.c 2011-06-03 22:25:56.358274709 +0800 +++ drivers/gpio/gpio-mxc.c 2011-06-01 18:38:21.410182809 +0800 @@ -24,11 +24,28 @@ #include #include #include +#include +#include #include #include -static struct mxc_gpio_port *mxc_gpio_ports; -static int gpio_table_size; +struct mxc_gpio_port { + struct list_head node; + void __iomem *base; + int irq; + int irq_high; + int virtual_irq_start; + struct gpio_chip chip; + u32 both_edges; + spinlock_t lock; +}; + +/* + * MX2 has one interrupt *for all* gpio ports. The list is used + * to save the references to all ports, so that mx2_gpio_irq_handler + * can walk through all interrupt status registers. + */ +static LIST_HEAD(mxc_gpio_ports); #define cpu_is_mx1_mx2() (cpu_is_mx1() || cpu_is_mx2()) @@ -50,7 +67,7 @@ static int gpio_table_size; static void _clear_gpio_irqstatus(struct mxc_gpio_port *port, u32 index) { - __raw_writel(1 << index, port->base + GPIO_ISR); + writel(1 << index, port->base + GPIO_ISR); } static void _set_gpio_irqenable(struct mxc_gpio_port *port, u32 index, @@ -58,27 +75,30 @@ static void _set_gpio_irqenable(struct m { u32 l; - l = __raw_readl(port->base + GPIO_IMR); + l = readl(port->base + GPIO_IMR); l = (l & (~(1 << index))) | (!!enable << index); - __raw_writel(l, port->base + GPIO_IMR); + writel(l, port->base + GPIO_IMR); } static void gpio_ack_irq(struct irq_data *d) { + struct mxc_gpio_port *port = irq_data_get_irq_chip_data(d); u32 gpio = irq_to_gpio(d->irq); - _clear_gpio_irqstatus(&mxc_gpio_ports[gpio / 32], gpio & 0x1f); + _clear_gpio_irqstatus(port, gpio & 0x1f); } static void gpio_mask_irq(struct irq_data *d) { + struct mxc_gpio_port *port = irq_data_get_irq_chip_data(d); u32 gpio = irq_to_gpio(d->irq); - _set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 0); + _set_gpio_irqenable(port, gpio & 0x1f, 0); } static void gpio_unmask_irq(struct irq_data *d) { + struct mxc_gpio_port *port = irq_data_get_irq_chip_data(d); u32 gpio = irq_to_gpio(d->irq); - _set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 1); + _set_gpio_irqenable(port, gpio & 0x1f, 1); } static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset); @@ -86,7 +106,7 @@ static int mxc_gpio_get(struct gpio_chip static int gpio_set_irq_type(struct irq_data *d, u32 type) { u32 gpio = irq_to_gpio(d->irq); - struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32]; + struct mxc_gpio_port *port = irq_data_get_irq_chip_data(d); u32 bit, val; int edge; void __iomem *reg = port->base; @@ -122,8 +142,8 @@ static int gpio_set_irq_type(struct irq_ reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */ bit = gpio & 0xf; - val = __raw_readl(reg) & ~(0x3 << (bit << 1)); - __raw_writel(val | (edge << (bit << 1)), reg); + val = readl(reg) & ~(0x3 << (bit << 1)); + writel(val | (edge << (bit << 1)), reg); _clear_gpio_irqstatus(port, gpio & 0x1f); return 0; @@ -137,7 +157,7 @@ static void mxc_flip_edge(struct mxc_gpi reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */ bit = gpio & 0xf; - val = __raw_readl(reg); + val = readl(reg); edge = (val >> (bit << 1)) & 3; val &= ~(0x3 << (bit << 1)); if (edge == GPIO_INT_HIGH_LEV) { @@ -151,7 +171,7 @@ static void mxc_flip_edge(struct mxc_gpi gpio, edge); return; } - __raw_writel(val | (edge << (bit << 1)), reg); + writel(val | (edge << (bit << 1)), reg); } /* handle 32 interrupts in one status register */ @@ -177,8 +197,7 @@ static void mx3_gpio_irq_handler(u32 irq u32 irq_stat; struct mxc_gpio_port *port = irq_get_handler_data(irq); - irq_stat = __raw_readl(port->base + GPIO_ISR) & - __raw_readl(port->base + GPIO_IMR); + irq_stat = readl(port->base + GPIO_ISR) & readl(port->base + GPIO_IMR); mxc_gpio_irq_handler(port, irq_stat); } @@ -186,19 +205,18 @@ static void mx3_gpio_irq_handler(u32 irq /* MX2 has one interrupt *for all* gpio ports */ static void mx2_gpio_irq_handler(u32 irq, struct irq_desc *desc) { - int i; u32 irq_msk, irq_stat; - struct mxc_gpio_port *port = irq_get_handler_data(irq); + struct mxc_gpio_port *port; /* walk through all interrupt status registers */ - for (i = 0; i < gpio_table_size; i++) { - irq_msk = __raw_readl(port[i].base + GPIO_IMR); + list_for_each_entry(port, &mxc_gpio_ports, node) { + irq_msk = readl(port->base + GPIO_IMR); if (!irq_msk) continue; - irq_stat = __raw_readl(port[i].base + GPIO_ISR) & irq_msk; + irq_stat = readl(port->base + GPIO_ISR) & irq_msk; if (irq_stat) - mxc_gpio_irq_handler(&port[i], irq_stat); + mxc_gpio_irq_handler(port, irq_stat); } } @@ -215,7 +233,7 @@ static int gpio_set_wake_irq(struct irq_ { u32 gpio = irq_to_gpio(d->irq); u32 gpio_idx = gpio & 0x1F; - struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32]; + struct mxc_gpio_port *port = irq_data_get_irq_chip_data(d); if (enable) { if (port->irq_high && (gpio_idx >= 16)) @@ -250,12 +268,12 @@ static void _set_gpio_direction(struct g unsigned long flags; spin_lock_irqsave(&port->lock, flags); - l = __raw_readl(port->base + GPIO_GDIR); + l = readl(port->base + GPIO_GDIR); if (dir) l |= 1 << offset; else l &= ~(1 << offset); - __raw_writel(l, port->base + GPIO_GDIR); + writel(l, port->base + GPIO_GDIR); spin_unlock_irqrestore(&port->lock, flags); } @@ -268,8 +286,8 @@ static void mxc_gpio_set(struct gpio_chi unsigned long flags; spin_lock_irqsave(&port->lock, flags); - l = (__raw_readl(reg) & (~(1 << offset))) | (!!value << offset); - __raw_writel(l, reg); + l = (readl(reg) & (~(1 << offset))) | (!!value << offset); + writel(l, reg); spin_unlock_irqrestore(&port->lock, flags); } @@ -278,7 +296,7 @@ static int mxc_gpio_get(struct gpio_chip struct mxc_gpio_port *port = container_of(chip, struct mxc_gpio_port, chip); - return (__raw_readl(port->base + GPIO_PSR) >> offset) & 1; + return (readl(port->base + GPIO_PSR) >> offset) & 1; } static int mxc_gpio_direction_input(struct gpio_chip *chip, unsigned offset) @@ -301,61 +319,115 @@ static int mxc_gpio_direction_output(str */ static struct lock_class_key gpio_lock_class; -int __init mxc_gpio_init(struct mxc_gpio_port *port, int cnt) +static int __devinit mxc_gpio_probe(struct platform_device *pdev) { - int i, j; + struct mxc_gpio_port *port; + struct resource *iores; + int err, i; + + port = kzalloc(sizeof(struct mxc_gpio_port), GFP_KERNEL); + if (!port) + return -ENOMEM; + + port->virtual_irq_start = MXC_GPIO_IRQ_START + pdev->id * 32; + + iores = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!iores) { + err = -ENODEV; + goto out_kfree; + } - /* save for local usage */ - mxc_gpio_ports = port; - gpio_table_size = cnt; - - printk(KERN_INFO "MXC GPIO hardware\n"); - - for (i = 0; i < cnt; i++) { - /* disable the interrupt and clear the status */ - __raw_writel(0, port[i].base + GPIO_IMR); - __raw_writel(~0, port[i].base + GPIO_ISR); - for (j = port[i].virtual_irq_start; - j < port[i].virtual_irq_start + 32; j++) { - irq_set_lockdep_class(j, &gpio_lock_class); - irq_set_chip_and_handler(j, &gpio_irq_chip, - handle_level_irq); - set_irq_flags(j, IRQF_VALID); - } + if (!request_mem_region(iores->start, resource_size(iores), + pdev->name)) { + err = -EBUSY; + goto out_kfree; + } - /* register gpio chip */ - port[i].chip.direction_input = mxc_gpio_direction_input; - port[i].chip.direction_output = mxc_gpio_direction_output; - port[i].chip.get = mxc_gpio_get; - port[i].chip.set = mxc_gpio_set; - port[i].chip.base = i * 32; - port[i].chip.ngpio = 32; - - spin_lock_init(&port[i].lock); - - /* its a serious configuration bug when it fails */ - BUG_ON( gpiochip_add(&port[i].chip) < 0 ); - - if (cpu_is_mx1() || cpu_is_mx3() || cpu_is_mx25() || cpu_is_mx51()) { - /* setup one handler for each entry */ - irq_set_chained_handler(port[i].irq, - mx3_gpio_irq_handler); - irq_set_handler_data(port[i].irq, &port[i]); - if (port[i].irq_high) { - /* setup handler for GPIO 16 to 31 */ - irq_set_chained_handler(port[i].irq_high, - mx3_gpio_irq_handler); - irq_set_handler_data(port[i].irq_high, - &port[i]); - } - } + port->base = ioremap(iores->start, resource_size(iores)); + if (!port->base) { + err = -ENOMEM; + goto out_release_mem; + } + + port->irq_high = platform_get_irq(pdev, 1); + port->irq = platform_get_irq(pdev, 0); + if (port->irq < 0) { + err = -EINVAL; + goto out_iounmap; + } + + /* disable the interrupt and clear the status */ + writel(0, port->base + GPIO_IMR); + writel(~0, port->base + GPIO_ISR); + + for (i = port->virtual_irq_start; + i < port->virtual_irq_start + 32; i++) { + irq_set_lockdep_class(i, &gpio_lock_class); + irq_set_chip_and_handler(i, &gpio_irq_chip, handle_level_irq); + set_irq_flags(i, IRQF_VALID); + irq_set_chip_data(i, port); } if (cpu_is_mx2()) { /* setup one handler for all GPIO interrupts */ - irq_set_chained_handler(port[0].irq, mx2_gpio_irq_handler); - irq_set_handler_data(port[0].irq, port); + if (pdev->id == 0) + irq_set_chained_handler(port->irq, + mx2_gpio_irq_handler); + } else { + /* setup one handler for each entry */ + irq_set_chained_handler(port->irq, mx3_gpio_irq_handler); + irq_set_handler_data(port->irq, port); + if (port->irq_high > 0) { + /* setup handler for GPIO 16 to 31 */ + irq_set_chained_handler(port->irq_high, + mx3_gpio_irq_handler); + irq_set_handler_data(port->irq_high, port); + } } + /* register gpio chip */ + port->chip.direction_input = mxc_gpio_direction_input; + port->chip.direction_output = mxc_gpio_direction_output; + port->chip.get = mxc_gpio_get; + port->chip.set = mxc_gpio_set; + port->chip.base = pdev->id * 32; + port->chip.ngpio = 32; + + spin_lock_init(&port->lock); + + err = gpiochip_add(&port->chip); + if (err) + goto out_iounmap; + + list_add_tail(&port->node, &mxc_gpio_ports); + return 0; + +out_iounmap: + iounmap(port->base); +out_release_mem: + release_mem_region(iores->start, resource_size(iores)); +out_kfree: + kfree(port); + dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, err); + return err; } + +static struct platform_driver mxc_gpio_driver = { + .driver = { + .name = "gpio-mxc", + }, + .probe = mxc_gpio_probe, +}; + +static int __init gpio_mxc_init(void) +{ + return platform_driver_register(&mxc_gpio_driver); +} +postcore_initcall(gpio_mxc_init); + +MODULE_AUTHOR("Freescale Semiconductor, " + "Daniel Mack , " + "Juergen Beisert "); +MODULE_DESCRIPTION("Freescale MXC GPIO"); +MODULE_LICENSE("GPL");