+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (c) 2010 Samsung Electronics Co., Ltd.
- * http://www.samsung.com
- *
- * PATA driver for Samsung SoCs.
- * Supports CF Interface in True IDE mode. Currently only PIO mode has been
- * implemented; UDMA support has to be added.
- *
- * Based on:
- * PATA driver for AT91SAM9260 Static Memory Controller
- * PATA driver for Toshiba SCC controller
-*/
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/mod_devicetable.h>
-#include <linux/init.h>
-#include <linux/clk.h>
-#include <linux/libata.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-
-#include <linux/platform_data/ata-samsung_cf.h>
-
-#define DRV_NAME "pata_samsung_cf"
-#define DRV_VERSION "0.1"
-
-#define S3C_CFATA_REG(x) (x)
-#define S3C_CFATA_MUX S3C_CFATA_REG(0x0)
-#define S3C_ATA_CTRL S3C_CFATA_REG(0x0)
-#define S3C_ATA_CMD S3C_CFATA_REG(0x8)
-#define S3C_ATA_IRQ S3C_CFATA_REG(0x10)
-#define S3C_ATA_IRQ_MSK S3C_CFATA_REG(0x14)
-#define S3C_ATA_CFG S3C_CFATA_REG(0x18)
-
-#define S3C_ATA_PIO_TIME S3C_CFATA_REG(0x2c)
-#define S3C_ATA_PIO_DTR S3C_CFATA_REG(0x54)
-#define S3C_ATA_PIO_FED S3C_CFATA_REG(0x58)
-#define S3C_ATA_PIO_SCR S3C_CFATA_REG(0x5c)
-#define S3C_ATA_PIO_LLR S3C_CFATA_REG(0x60)
-#define S3C_ATA_PIO_LMR S3C_CFATA_REG(0x64)
-#define S3C_ATA_PIO_LHR S3C_CFATA_REG(0x68)
-#define S3C_ATA_PIO_DVR S3C_CFATA_REG(0x6c)
-#define S3C_ATA_PIO_CSD S3C_CFATA_REG(0x70)
-#define S3C_ATA_PIO_DAD S3C_CFATA_REG(0x74)
-#define S3C_ATA_PIO_RDATA S3C_CFATA_REG(0x7c)
-
-#define S3C_CFATA_MUX_TRUEIDE 0x01
-#define S3C_ATA_CFG_SWAP 0x40
-#define S3C_ATA_CFG_IORDYEN 0x02
-
-enum s3c_cpu_type {
- TYPE_S3C64XX,
- TYPE_S5PV210,
-};
-
-/*
- * struct s3c_ide_info - S3C PATA instance.
- * @clk: The clock resource for this controller.
- * @ide_addr: The area mapped for the hardware registers.
- * @sfr_addr: The area mapped for the special function registers.
- * @irq: The IRQ number we are using.
- * @cpu_type: The exact type of this controller.
- * @fifo_status_reg: The ATA_FIFO_STATUS register offset.
- */
-struct s3c_ide_info {
- struct clk *clk;
- void __iomem *ide_addr;
- void __iomem *sfr_addr;
- int irq;
- enum s3c_cpu_type cpu_type;
- unsigned int fifo_status_reg;
-};
-
-static void pata_s3c_set_endian(void __iomem *s3c_ide_regbase, u8 mode)
-{
- u32 reg = readl(s3c_ide_regbase + S3C_ATA_CFG);
- reg = mode ? (reg & ~S3C_ATA_CFG_SWAP) : (reg | S3C_ATA_CFG_SWAP);
- writel(reg, s3c_ide_regbase + S3C_ATA_CFG);
-}
-
-static void pata_s3c_cfg_mode(void __iomem *s3c_ide_sfrbase)
-{
- /* Select true-ide as the internal operating mode */
- writel(readl(s3c_ide_sfrbase + S3C_CFATA_MUX) | S3C_CFATA_MUX_TRUEIDE,
- s3c_ide_sfrbase + S3C_CFATA_MUX);
-}
-
-static unsigned long
-pata_s3c_setup_timing(struct s3c_ide_info *info, const struct ata_timing *ata)
-{
- int t1 = ata->setup;
- int t2 = ata->act8b;
- int t2i = ata->rec8b;
- ulong piotime;
-
- piotime = ((t2i & 0xff) << 12) | ((t2 & 0xff) << 4) | (t1 & 0xf);
-
- return piotime;
-}
-
-static void pata_s3c_set_piomode(struct ata_port *ap, struct ata_device *adev)
-{
- struct s3c_ide_info *info = ap->host->private_data;
- struct ata_timing timing;
- int cycle_time;
- ulong ata_cfg = readl(info->ide_addr + S3C_ATA_CFG);
- ulong piotime;
-
- /* Enables IORDY if mode requires it */
- if (ata_pio_need_iordy(adev))
- ata_cfg |= S3C_ATA_CFG_IORDYEN;
- else
- ata_cfg &= ~S3C_ATA_CFG_IORDYEN;
-
- cycle_time = (int)(1000000000UL / clk_get_rate(info->clk));
-
- ata_timing_compute(adev, adev->pio_mode, &timing,
- cycle_time * 1000, 0);
-
- piotime = pata_s3c_setup_timing(info, &timing);
-
- writel(ata_cfg, info->ide_addr + S3C_ATA_CFG);
- writel(piotime, info->ide_addr + S3C_ATA_PIO_TIME);
-}
-
-/*
- * Waits until the IDE controller is able to perform next read/write
- * operation to the disk. Needed for 64XX series boards only.
- */
-static int wait_for_host_ready(struct s3c_ide_info *info)
-{
- ulong timeout;
- void __iomem *fifo_reg = info->ide_addr + info->fifo_status_reg;
-
- /* wait for maximum of 20 msec */
- timeout = jiffies + msecs_to_jiffies(20);
- while (time_before(jiffies, timeout)) {
- if ((readl(fifo_reg) >> 28) == 0)
- return 0;
- }
- return -EBUSY;
-}
-
-/*
- * Writes to one of the task file registers.
- */
-static void ata_outb(struct ata_host *host, u8 addr, void __iomem *reg)
-{
- struct s3c_ide_info *info = host->private_data;
-
- wait_for_host_ready(info);
- writeb(addr, reg);
-}
-
-/*
- * Reads from one of the task file registers.
- */
-static u8 ata_inb(struct ata_host *host, void __iomem *reg)
-{
- struct s3c_ide_info *info = host->private_data;
- u8 temp;
-
- wait_for_host_ready(info);
- (void) readb(reg);
- wait_for_host_ready(info);
- temp = readb(info->ide_addr + S3C_ATA_PIO_RDATA);
- return temp;
-}
-
-/*
- * pata_s3c_tf_load - send taskfile registers to host controller
- */
-static void pata_s3c_tf_load(struct ata_port *ap,
- const struct ata_taskfile *tf)
-{
- struct ata_ioports *ioaddr = &ap->ioaddr;
- unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
-
- if (tf->ctl != ap->last_ctl) {
- ata_outb(ap->host, tf->ctl, ioaddr->ctl_addr);
- ap->last_ctl = tf->ctl;
- ata_wait_idle(ap);
- }
-
- if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
- ata_outb(ap->host, tf->hob_feature, ioaddr->feature_addr);
- ata_outb(ap->host, tf->hob_nsect, ioaddr->nsect_addr);
- ata_outb(ap->host, tf->hob_lbal, ioaddr->lbal_addr);
- ata_outb(ap->host, tf->hob_lbam, ioaddr->lbam_addr);
- ata_outb(ap->host, tf->hob_lbah, ioaddr->lbah_addr);
- }
-
- if (is_addr) {
- ata_outb(ap->host, tf->feature, ioaddr->feature_addr);
- ata_outb(ap->host, tf->nsect, ioaddr->nsect_addr);
- ata_outb(ap->host, tf->lbal, ioaddr->lbal_addr);
- ata_outb(ap->host, tf->lbam, ioaddr->lbam_addr);
- ata_outb(ap->host, tf->lbah, ioaddr->lbah_addr);
- }
-
- if (tf->flags & ATA_TFLAG_DEVICE)
- ata_outb(ap->host, tf->device, ioaddr->device_addr);
-
- ata_wait_idle(ap);
-}
-
-/*
- * pata_s3c_tf_read - input device's ATA taskfile shadow registers
- */
-static void pata_s3c_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
-{
- struct ata_ioports *ioaddr = &ap->ioaddr;
-
- tf->error = ata_inb(ap->host, ioaddr->error_addr);
- tf->nsect = ata_inb(ap->host, ioaddr->nsect_addr);
- tf->lbal = ata_inb(ap->host, ioaddr->lbal_addr);
- tf->lbam = ata_inb(ap->host, ioaddr->lbam_addr);
- tf->lbah = ata_inb(ap->host, ioaddr->lbah_addr);
- tf->device = ata_inb(ap->host, ioaddr->device_addr);
-
- if (tf->flags & ATA_TFLAG_LBA48) {
- ata_outb(ap->host, tf->ctl | ATA_HOB, ioaddr->ctl_addr);
- tf->hob_feature = ata_inb(ap->host, ioaddr->error_addr);
- tf->hob_nsect = ata_inb(ap->host, ioaddr->nsect_addr);
- tf->hob_lbal = ata_inb(ap->host, ioaddr->lbal_addr);
- tf->hob_lbam = ata_inb(ap->host, ioaddr->lbam_addr);
- tf->hob_lbah = ata_inb(ap->host, ioaddr->lbah_addr);
- ata_outb(ap->host, tf->ctl, ioaddr->ctl_addr);
- ap->last_ctl = tf->ctl;
- }
-}
-
-/*
- * pata_s3c_exec_command - issue ATA command to host controller
- */
-static void pata_s3c_exec_command(struct ata_port *ap,
- const struct ata_taskfile *tf)
-{
- ata_outb(ap->host, tf->command, ap->ioaddr.command_addr);
- ata_sff_pause(ap);
-}
-
-/*
- * pata_s3c_check_status - Read device status register
- */
-static u8 pata_s3c_check_status(struct ata_port *ap)
-{
- return ata_inb(ap->host, ap->ioaddr.status_addr);
-}
-
-/*
- * pata_s3c_check_altstatus - Read alternate device status register
- */
-static u8 pata_s3c_check_altstatus(struct ata_port *ap)
-{
- return ata_inb(ap->host, ap->ioaddr.altstatus_addr);
-}
-
-/*
- * pata_s3c_data_xfer - Transfer data by PIO
- */
-static unsigned int pata_s3c_data_xfer(struct ata_queued_cmd *qc,
- unsigned char *buf, unsigned int buflen, int rw)
-{
- struct ata_port *ap = qc->dev->link->ap;
- struct s3c_ide_info *info = ap->host->private_data;
- void __iomem *data_addr = ap->ioaddr.data_addr;
- unsigned int words = buflen >> 1, i;
- u16 *data_ptr = (u16 *)buf;
-
- /* Requires wait same as in ata_inb/ata_outb */
- if (rw == READ)
- for (i = 0; i < words; i++, data_ptr++) {
- wait_for_host_ready(info);
- (void) readw(data_addr);
- wait_for_host_ready(info);
- *data_ptr = readw(info->ide_addr
- + S3C_ATA_PIO_RDATA);
- }
- else
- for (i = 0; i < words; i++, data_ptr++) {
- wait_for_host_ready(info);
- writew(*data_ptr, data_addr);
- }
-
- if (buflen & 0x01)
- dev_err(ap->dev, "unexpected trailing data\n");
-
- return words << 1;
-}
-
-/*
- * pata_s3c_dev_select - Select device on ATA bus
- */
-static void pata_s3c_dev_select(struct ata_port *ap, unsigned int device)
-{
- u8 tmp = ATA_DEVICE_OBS;
-
- if (device != 0)
- tmp |= ATA_DEV1;
-
- ata_outb(ap->host, tmp, ap->ioaddr.device_addr);
- ata_sff_pause(ap);
-}
-
-/*
- * pata_s3c_devchk - PATA device presence detection
- */
-static bool pata_s3c_devchk(struct ata_port *ap, unsigned int device)
-{
- struct ata_ioports *ioaddr = &ap->ioaddr;
- u8 nsect, lbal;
-
- pata_s3c_dev_select(ap, device);
-
- ata_outb(ap->host, 0x55, ioaddr->nsect_addr);
- ata_outb(ap->host, 0xaa, ioaddr->lbal_addr);
-
- ata_outb(ap->host, 0xaa, ioaddr->nsect_addr);
- ata_outb(ap->host, 0x55, ioaddr->lbal_addr);
-
- ata_outb(ap->host, 0x55, ioaddr->nsect_addr);
- ata_outb(ap->host, 0xaa, ioaddr->lbal_addr);
-
- nsect = ata_inb(ap->host, ioaddr->nsect_addr);
- lbal = ata_inb(ap->host, ioaddr->lbal_addr);
-
- if ((nsect == 0x55) && (lbal == 0xaa))
- return true; /* we found a device */
-
- return false; /* nothing found */
-}
-
-/*
- * pata_s3c_wait_after_reset - wait for devices to become ready after reset
- */
-static int pata_s3c_wait_after_reset(struct ata_link *link,
- unsigned long deadline)
-{
- int rc;
-
- ata_msleep(link->ap, ATA_WAIT_AFTER_RESET);
-
- /* always check readiness of the master device */
- rc = ata_sff_wait_ready(link, deadline);
- /* -ENODEV means the odd clown forgot the D7 pulldown resistor
- * and TF status is 0xff, bail out on it too.
- */
- if (rc)
- return rc;
-
- return 0;
-}
-
-/*
- * pata_s3c_bus_softreset - PATA device software reset
- */
-static int pata_s3c_bus_softreset(struct ata_port *ap,
- unsigned long deadline)
-{
- struct ata_ioports *ioaddr = &ap->ioaddr;
-
- /* software reset. causes dev0 to be selected */
- ata_outb(ap->host, ap->ctl, ioaddr->ctl_addr);
- udelay(20);
- ata_outb(ap->host, ap->ctl | ATA_SRST, ioaddr->ctl_addr);
- udelay(20);
- ata_outb(ap->host, ap->ctl, ioaddr->ctl_addr);
- ap->last_ctl = ap->ctl;
-
- return pata_s3c_wait_after_reset(&ap->link, deadline);
-}
-
-/*
- * pata_s3c_softreset - reset host port via ATA SRST
- */
-static int pata_s3c_softreset(struct ata_link *link, unsigned int *classes,
- unsigned long deadline)
-{
- struct ata_port *ap = link->ap;
- unsigned int devmask = 0;
- int rc;
- u8 err;
-
- /* determine if device 0 is present */
- if (pata_s3c_devchk(ap, 0))
- devmask |= (1 << 0);
-
- /* select device 0 again */
- pata_s3c_dev_select(ap, 0);
-
- /* issue bus reset */
- rc = pata_s3c_bus_softreset(ap, deadline);
- /* if link is occupied, -ENODEV too is an error */
- if (rc && rc != -ENODEV) {
- ata_link_err(link, "SRST failed (errno=%d)\n", rc);
- return rc;
- }
-
- /* determine by signature whether we have ATA or ATAPI devices */
- classes[0] = ata_sff_dev_classify(&ap->link.device[0],
- devmask & (1 << 0), &err);
-
- return 0;
-}
-
-/*
- * pata_s3c_set_devctl - Write device control register
- */
-static void pata_s3c_set_devctl(struct ata_port *ap, u8 ctl)
-{
- ata_outb(ap->host, ctl, ap->ioaddr.ctl_addr);
-}
-
-static struct scsi_host_template pata_s3c_sht = {
- ATA_PIO_SHT(DRV_NAME),
-};
-
-static struct ata_port_operations pata_s3c_port_ops = {
- .inherits = &ata_sff_port_ops,
- .sff_check_status = pata_s3c_check_status,
- .sff_check_altstatus = pata_s3c_check_altstatus,
- .sff_tf_load = pata_s3c_tf_load,
- .sff_tf_read = pata_s3c_tf_read,
- .sff_data_xfer = pata_s3c_data_xfer,
- .sff_exec_command = pata_s3c_exec_command,
- .sff_dev_select = pata_s3c_dev_select,
- .sff_set_devctl = pata_s3c_set_devctl,
- .softreset = pata_s3c_softreset,
- .set_piomode = pata_s3c_set_piomode,
-};
-
-static struct ata_port_operations pata_s5p_port_ops = {
- .inherits = &ata_sff_port_ops,
- .set_piomode = pata_s3c_set_piomode,
-};
-
-static void pata_s3c_enable(void __iomem *s3c_ide_regbase, bool state)
-{
- u32 temp = readl(s3c_ide_regbase + S3C_ATA_CTRL);
- temp = state ? (temp | 1) : (temp & ~1);
- writel(temp, s3c_ide_regbase + S3C_ATA_CTRL);
-}
-
-static irqreturn_t pata_s3c_irq(int irq, void *dev_instance)
-{
- struct ata_host *host = dev_instance;
- struct s3c_ide_info *info = host->private_data;
- u32 reg;
-
- reg = readl(info->ide_addr + S3C_ATA_IRQ);
- writel(reg, info->ide_addr + S3C_ATA_IRQ);
-
- return ata_sff_interrupt(irq, dev_instance);
-}
-
-static void pata_s3c_hwinit(struct s3c_ide_info *info,
- struct s3c_ide_platdata *pdata)
-{
- switch (info->cpu_type) {
- case TYPE_S3C64XX:
- /* Configure as big endian */
- pata_s3c_cfg_mode(info->sfr_addr);
- pata_s3c_set_endian(info->ide_addr, 1);
- pata_s3c_enable(info->ide_addr, true);
- msleep(100);
-
- /* Remove IRQ Status */
- writel(0x1f, info->ide_addr + S3C_ATA_IRQ);
- writel(0x1b, info->ide_addr + S3C_ATA_IRQ_MSK);
- break;
-
- case TYPE_S5PV210:
- /* Configure as little endian */
- pata_s3c_set_endian(info->ide_addr, 0);
- pata_s3c_enable(info->ide_addr, true);
- msleep(100);
-
- /* Remove IRQ Status */
- writel(0x3f, info->ide_addr + S3C_ATA_IRQ);
- writel(0x3f, info->ide_addr + S3C_ATA_IRQ_MSK);
- break;
-
- default:
- BUG();
- }
-}
-
-static int __init pata_s3c_probe(struct platform_device *pdev)
-{
- struct s3c_ide_platdata *pdata = dev_get_platdata(&pdev->dev);
- struct device *dev = &pdev->dev;
- struct s3c_ide_info *info;
- struct resource *res;
- struct ata_port *ap;
- struct ata_host *host;
- enum s3c_cpu_type cpu_type;
- int ret;
-
- cpu_type = platform_get_device_id(pdev)->driver_data;
-
- info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
- if (!info)
- return -ENOMEM;
-
- info->irq = platform_get_irq(pdev, 0);
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-
- info->ide_addr = devm_ioremap_resource(dev, res);
- if (IS_ERR(info->ide_addr))
- return PTR_ERR(info->ide_addr);
-
- info->clk = devm_clk_get(&pdev->dev, "cfcon");
- if (IS_ERR(info->clk)) {
- dev_err(dev, "failed to get access to cf controller clock\n");
- ret = PTR_ERR(info->clk);
- info->clk = NULL;
- return ret;
- }
-
- clk_enable(info->clk);
-
- /* init ata host */
- host = ata_host_alloc(dev, 1);
- if (!host) {
- dev_err(dev, "failed to allocate ide host\n");
- ret = -ENOMEM;
- goto stop_clk;
- }
-
- ap = host->ports[0];
- ap->pio_mask = ATA_PIO4;
-
- if (cpu_type == TYPE_S3C64XX) {
- ap->ops = &pata_s3c_port_ops;
- info->sfr_addr = info->ide_addr + 0x1800;
- info->ide_addr += 0x1900;
- info->fifo_status_reg = 0x94;
- } else {
- ap->ops = &pata_s5p_port_ops;
- info->fifo_status_reg = 0x84;
- }
-
- info->cpu_type = cpu_type;
-
- if (info->irq <= 0) {
- ap->flags |= ATA_FLAG_PIO_POLLING;
- info->irq = 0;
- ata_port_desc(ap, "no IRQ, using PIO polling\n");
- }
-
- ap->ioaddr.cmd_addr = info->ide_addr + S3C_ATA_CMD;
- ap->ioaddr.data_addr = info->ide_addr + S3C_ATA_PIO_DTR;
- ap->ioaddr.error_addr = info->ide_addr + S3C_ATA_PIO_FED;
- ap->ioaddr.feature_addr = info->ide_addr + S3C_ATA_PIO_FED;
- ap->ioaddr.nsect_addr = info->ide_addr + S3C_ATA_PIO_SCR;
- ap->ioaddr.lbal_addr = info->ide_addr + S3C_ATA_PIO_LLR;
- ap->ioaddr.lbam_addr = info->ide_addr + S3C_ATA_PIO_LMR;
- ap->ioaddr.lbah_addr = info->ide_addr + S3C_ATA_PIO_LHR;
- ap->ioaddr.device_addr = info->ide_addr + S3C_ATA_PIO_DVR;
- ap->ioaddr.status_addr = info->ide_addr + S3C_ATA_PIO_CSD;
- ap->ioaddr.command_addr = info->ide_addr + S3C_ATA_PIO_CSD;
- ap->ioaddr.altstatus_addr = info->ide_addr + S3C_ATA_PIO_DAD;
- ap->ioaddr.ctl_addr = info->ide_addr + S3C_ATA_PIO_DAD;
-
- ata_port_desc(ap, "mmio cmd 0x%llx ",
- (unsigned long long)res->start);
-
- host->private_data = info;
-
- if (pdata && pdata->setup_gpio)
- pdata->setup_gpio();
-
- /* Set endianness and enable the interface */
- pata_s3c_hwinit(info, pdata);
-
- ret = ata_host_activate(host, info->irq,
- info->irq ? pata_s3c_irq : NULL,
- 0, &pata_s3c_sht);
- if (ret)
- goto stop_clk;
-
- return 0;
-
-stop_clk:
- clk_disable(info->clk);
- return ret;
-}
-
-static int __exit pata_s3c_remove(struct platform_device *pdev)
-{
- struct ata_host *host = platform_get_drvdata(pdev);
- struct s3c_ide_info *info = host->private_data;
-
- ata_host_detach(host);
-
- clk_disable(info->clk);
-
- return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int pata_s3c_suspend(struct device *dev)
-{
- struct ata_host *host = dev_get_drvdata(dev);
-
- ata_host_suspend(host, PMSG_SUSPEND);
- return 0;
-}
-
-static int pata_s3c_resume(struct device *dev)
-{
- struct ata_host *host = dev_get_drvdata(dev);
- struct s3c_ide_platdata *pdata = dev_get_platdata(dev);
- struct s3c_ide_info *info = host->private_data;
-
- pata_s3c_hwinit(info, pdata);
- ata_host_resume(host);
-
- return 0;
-}
-
-static const struct dev_pm_ops pata_s3c_pm_ops = {
- .suspend = pata_s3c_suspend,
- .resume = pata_s3c_resume,
-};
-#endif
-
-/* driver device registration */
-static const struct platform_device_id pata_s3c_driver_ids[] = {
- {
- .name = "s3c64xx-pata",
- .driver_data = TYPE_S3C64XX,
- }, {
- .name = "s5pv210-pata",
- .driver_data = TYPE_S5PV210,
- },
- { }
-};
-
-MODULE_DEVICE_TABLE(platform, pata_s3c_driver_ids);
-
-static struct platform_driver pata_s3c_driver = {
- .remove = __exit_p(pata_s3c_remove),
- .id_table = pata_s3c_driver_ids,
- .driver = {
- .name = DRV_NAME,
-#ifdef CONFIG_PM_SLEEP
- .pm = &pata_s3c_pm_ops,
-#endif
- },
-};
-
-module_platform_driver_probe(pata_s3c_driver, pata_s3c_probe);
-
-MODULE_AUTHOR("Abhilash Kesavan, <a.kesavan@samsung.com>");
-MODULE_DESCRIPTION("low-level driver for Samsung PATA controller");
-MODULE_LICENSE("GPL");
-MODULE_VERSION(DRV_VERSION);
projects / platform / kernel / linux-rpi.git / commitdiff