Hello
I have some minor comment below:
On Fri, Sep 16, 2016 at 12:39:25PM +0200, Cédric Le Goater wrote:
> From: Alistair Popple <alistair@xxxxxxxxxxxx>
>
> This patch adds a simple device driver to expose the iBT interface on
> Aspeed SOCs (AST2400 and AST2500) as a character device. Such SOCs are
> commonly used as BMCs (BaseBoard Management Controllers) and this
> driver implements the BMC side of the BT interface.
>
> The BT (Block Transfer) interface is used to perform in-band IPMI
> communication between a host and its BMC. Entire messages are buffered
> before sending a notification to the other end, host or BMC, that
> there is data to be read. Usually, the host emits requests and the BMC
> responses but the specification provides a mean for the BMC to send
> SMS Attention (BMC-to-Host attention or System Management Software
> attention) messages.
>
> For this purpose, the driver introduces a specific ioctl on the
> device: 'BT_BMC_IOCTL_SMS_ATN' that can be used by the system running
> on the BMC to signal the host of such an event.
>
> The device name defaults to '/dev/ipmi-bt-host'
>
> Signed-off-by: Alistair Popple <alistair@xxxxxxxxxxxx>
> Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxx>
> Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
> [clg: - checkpatch fixes
> - added a devicetree binding documentation
> - replace 'bt_host' by 'bt_bmc' to reflect that the driver is
> the BMC side of the IPMI BT interface
> - renamed the device to 'ipmi-bt-host'
> - introduced a temporary buffer to copy_{to,from}_user
> - used platform_get_irq()
> - moved the driver under drivers/char/ipmi/ but kept it as a misc
> device
> - changed the compatible cell to "aspeed,ast2400-bt-bmc"
> ]
> Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
> ---
>
> Changes since v1:
>
> - replace 'bt_host' by 'bt_bmc' to reflect that the driver is
> the BMC side of the IPMI BT interface
> - renamed the device to 'ipmi-bt-host'
> - introduced a temporary buffer to copy_{to,from}_user
> - used platform_get_irq()
> - moved the driver under drivers/char/ipmi/ but kept it as a misc
> device
> - changed the compatible cell to "aspeed,ast2400-bt-bmc"
>
> .../bindings/char/ipmi/aspeed,ast2400-bt-bmc.txt | 23 +
> drivers/Makefile | 2 +-
> drivers/char/ipmi/Kconfig | 7 +
> drivers/char/ipmi/Makefile | 1 +
> drivers/char/ipmi/bt-bmc.c | 486 +++++++++++++++++++++
> include/uapi/linux/Kbuild | 1 +
> include/uapi/linux/bt-bmc.h | 18 +
> 7 files changed, 537 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/devicetree/bindings/char/ipmi/aspeed,ast2400-bt-bmc.txt
> create mode 100644 drivers/char/ipmi/bt-bmc.c
> create mode 100644 include/uapi/linux/bt-bmc.h
>
> diff --git a/Documentation/devicetree/bindings/char/ipmi/aspeed,ast2400-bt-bmc.txt b/Documentation/devicetree/bindings/char/ipmi/aspeed,ast2400-bt-bmc.txt
> new file mode 100644
> index 000000000000..fbbacd958240
> --- /dev/null
[..]
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/errno.h>
> +#include <linux/poll.h>
> +#include <linux/sched.h>
> +#include <linux/spinlock.h>
> +#include <linux/slab.h>
> +#include <linux/init.h>
> +#include <linux/device.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/miscdevice.h>
> +#include <linux/timer.h>
> +#include <linux/jiffies.h>
> +#include <linux/bt-bmc.h>
Please sort them in alphabetical order, some of them seems not needed also (like spinlock.h)
> +
> +/*
> + * This is a BMC device used to communicate to the host
> + */
> +#define DEVICE_NAME "ipmi-bt-host"
> +
> +#define BT_IO_BASE 0xe4
> +#define BT_IRQ 10
> +
> +#define BT_CR0 0x0
> +#define BT_CR0_IO_BASE 16
> +#define BT_CR0_IRQ 12
> +#define BT_CR0_EN_CLR_SLV_RDP 0x8
> +#define BT_CR0_EN_CLR_SLV_WRP 0x4
> +#define BT_CR0_ENABLE_IBT 0x1
> +#define BT_CR1 0x4
> +#define BT_CR1_IRQ_H2B 0x01
> +#define BT_CR1_IRQ_HBUSY 0x40
> +#define BT_CR2 0x8
> +#define BT_CR2_IRQ_H2B 0x01
> +#define BT_CR2_IRQ_HBUSY 0x40
> +#define BT_CR3 0xc
> +#define BT_CTRL 0x10
> +#define BT_CTRL_B_BUSY 0x80
> +#define BT_CTRL_H_BUSY 0x40
> +#define BT_CTRL_OEM0 0x20
> +#define BT_CTRL_SMS_ATN 0x10
> +#define BT_CTRL_B2H_ATN 0x08
> +#define BT_CTRL_H2B_ATN 0x04
> +#define BT_CTRL_CLR_RD_PTR 0x02
> +#define BT_CTRL_CLR_WR_PTR 0x01
> +#define BT_BMC2HOST 0x14
> +#define BT_INTMASK 0x18
> +#define BT_INTMASK_B2H_IRQEN 0x01
> +#define BT_INTMASK_B2H_IRQ 0x02
> +#define BT_INTMASK_BMC_HWRST 0x80
Why to use 3 space after some define ?
[..]
> +
> +#define BT_BMC_BUFFER_SIZE 256
Put this define with others
[..]
> +
> +static irqreturn_t bt_bmc_irq(int irq, void *arg)
> +{
> + struct bt_bmc *bt_bmc = arg;
> + uint32_t reg;
u32 is prefered other uint32_t, do you have run checkpatch --strict ?
> +
> + reg = ioread32(bt_bmc->base + BT_CR2);
> + reg &= BT_CR2_IRQ_H2B | BT_CR2_IRQ_HBUSY;
> + if (!reg)
> + return IRQ_NONE;
> +
> + /* ack pending IRQs */
> + iowrite32(reg, bt_bmc->base + BT_CR2);
> +
> + wake_up(&bt_bmc->queue);
> + return IRQ_HANDLED;
> +}
> +
> +static int bt_bmc_config_irq(struct bt_bmc *bt_bmc,
> + struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + uint32_t reg;
> + int rc;
> +
> + bt_bmc->irq = platform_get_irq(pdev, 0);
> + if (!bt_bmc->irq)
> + return -ENODEV;
> +
> + rc = devm_request_irq(dev, bt_bmc->irq, bt_bmc_irq, IRQF_SHARED,
> + DEVICE_NAME, bt_bmc);
> + if (rc < 0) {
> + dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq);
> + bt_bmc->irq = 0;
> + return rc;
> + }
> +
> + /* Configure IRQs on the bmc clearing the H2B and HBUSY bits;
> + * H2B will be asserted when the bmc has data for us; HBUSY
> + * will be cleared (along with B2H) when we can write the next
> + * message to the BT buffer
> + */
This comment doesnt have the style recommended for new driver.
> + reg = ioread32(bt_bmc->base + BT_CR1);
> + reg |= BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY;
> + iowrite32(reg, bt_bmc->base + BT_CR1);
> +
> + return 0;
> +}
> +
> +static int bt_bmc_probe(struct platform_device *pdev)
> +{
> + struct bt_bmc *bt_bmc;
> + struct device *dev;
> + struct resource *res;
> + int rc;
> +
> + if (!pdev || !pdev->dev.of_node)
> + return -ENODEV;
> +
> + dev = &pdev->dev;
> + dev_info(dev, "Found bt bmc device\n");
> +
> + bt_bmc = devm_kzalloc(dev, sizeof(*bt_bmc), GFP_KERNEL);
> + if (!bt_bmc)
> + return -ENOMEM;
> +
> + dev_set_drvdata(&pdev->dev, bt_bmc);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(dev, "Unable to find resources\n");
> + rc = -ENXIO;
> + goto out_free;
> + }
> +
> + bt_bmc->base = devm_ioremap_resource(&pdev->dev, res);
> + if (!bt_bmc->base) {
> + rc = -ENOMEM;
> + goto out_free;
> + }
> +
> + init_waitqueue_head(&bt_bmc->queue);
> +
> + bt_bmc->miscdev.minor = MISC_DYNAMIC_MINOR,
> + bt_bmc->miscdev.name = DEVICE_NAME,
> + bt_bmc->miscdev.fops = &bt_bmc_fops,
> + bt_bmc->miscdev.parent = dev;
> + rc = misc_register(&bt_bmc->miscdev);
> + if (rc) {
> + dev_err(dev, "Unable to register device\n");
Be more precise by saying misc device
> + goto out_unmap;
> + }
> +
> + bt_bmc_config_irq(bt_bmc, pdev);
> +
> + if (bt_bmc->irq) {
> + dev_info(dev, "Using IRQ %d\n", bt_bmc->irq);
> + } else {
> + dev_info(dev, "No IRQ; using timer\n");
> + setup_timer(&bt_bmc->poll_timer, poll_timer,
> + (unsigned long)bt_bmc);
> + bt_bmc->poll_timer.expires = jiffies + msecs_to_jiffies(10);
> + add_timer(&bt_bmc->poll_timer);
> + }
> +
> + iowrite32((BT_IO_BASE << BT_CR0_IO_BASE) |
> + (BT_IRQ << BT_CR0_IRQ) |
> + BT_CR0_EN_CLR_SLV_RDP |
> + BT_CR0_EN_CLR_SLV_WRP |
> + BT_CR0_ENABLE_IBT,
> + bt_bmc->base + BT_CR0);
> +
> + clr_b_busy(bt_bmc);
> +
> + return 0;
> +
> +out_unmap:
> + devm_iounmap(&pdev->dev, bt_bmc->base);
Why do you use devm_iounmap/devm_kfree since the interest with devm_ functions is that all cleanup is done when driver is removed.
> +
> +out_free:
> + devm_kfree(dev, bt_bmc);
> + return rc;
I think you should remove the space after this return
Regards
Corentin Labbe
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