[PATCH V6 2/3] dma: add Qualcomm Technologies HIDMA management driver
okaya at codeaurora.org
okaya at codeaurora.org
Sun Nov 22 11:52:52 PST 2015
> On Sun, Nov 22, 2015 at 6:37 PM, Sinan Kaya <okaya at codeaurora.org> wrote:
>> The Qualcomm Technologies HIDMA device has been designed
>> to support virtualization technology. The driver has been
>> divided into two to follow the hardware design.
>>
>> 1. HIDMA Management driver
>> 2. HIDMA Channel driver
>>
>> Each HIDMA HW consists of multiple channels. These channels
>> share some set of common parameters. These parameters are
>> initialized by the management driver during power up.
>> Same management driver is used for monitoring the execution
>> of the channels. Management driver can change the performance
>> behavior dynamically such as bandwidth allocation and
>> prioritization.
>>
>> The management driver is executed in hypervisor context and
>> is the main management entity for all channels provided by
>> the device.
>
>> +What: /sys/devices/platform/hidma-mgmt*/channel*_weight
>> + /sys/devices/platform/QCOM8060:*/channel*__weight
>
> Extra _ ?
Done.
>
>
>> +Each HIDMA HW consists of multiple channels. These channels
>> +share some set of common parameters. These parameters are
>> +initialized by the management driver during power up.
>> +Same management driver is used for monitoring the execution
>> +of the channels. Management driver can change the performance
>> +behavior dynamically such as bandwidth allocation and
>> +prioritization.
>> +
>> +All channel devices get probed in the hypervisor
>> +context during power up. They show up as DMA engine
>> +DMA channels. Then, before starting the virtualization; each
>> +channel device is unbound from the hypervisor by VFIO
>> +and assign to the guest machine for control.
>> +
>> +This management driver will be used by the system
>> +admin to monitor/reset the execution state of the DMA
>> +channels. This will be the management interface.
>
> Hmm… Can lines be longer up to 76-78 characters?
>
>> +#define MAX_WR_XACTIONS_MASK 0x1F
>> +#define MAX_RD_XACTIONS_MASK 0x1F
>> +#define WEIGHT_MASK 0x7F
>> +#define MAX_BUS_REQ_LEN_MASK 0xFFFF
>> +#define CHRESET_TIMEOUUT_MASK 0xFFFFF
>
> GENMASK?
done
>
>> +int hidma_mgmt_setup(struct hidma_mgmt_dev *mgmtdev)
>> +{
>> + unsigned int i;
>> + u32 val;
>> +
>> + if (!is_power_of_2(mgmtdev->max_write_request) ||
>> + (mgmtdev->max_write_request < 128) ||
>
> Someone likes parens.
yes, I do. I don't trust compilers and also don't like to open holes for
people making quick changes to code while ignoring the operator precedence for
maintenance reasons.
> I might agree with these cases, but below in assignments and combined
> operations the parens are indeed redundant.
>
OK. I think we are already in personal style of code zone now. I have already
broken another review because you don't like for loops but rather have a while
loop.
I'll leave ifs and change the assignments only. I'll need your reviewed-by
once you are happy.
>> + (mgmtdev->max_write_request > 1024)) {
>> + dev_err(&mgmtdev->pdev->dev, "invalid write request %d\n",
>> + mgmtdev->max_write_request);
>> + return -EINVAL;
>> + }
>> +
>> + if (!is_power_of_2(mgmtdev->max_read_request) ||
>> + (mgmtdev->max_read_request < 128) ||
>> + (mgmtdev->max_read_request > 1024)) {
>
> Ditto.
>
>> + dev_err(&mgmtdev->pdev->dev, "invalid read request %d\n",
>> + mgmtdev->max_read_request);
>> + return -EINVAL;
>> + }
>> +
>> + if (mgmtdev->max_wr_xactions > MAX_WR_XACTIONS_MASK) {
>> + dev_err(&mgmtdev->pdev->dev,
>> + "max_wr_xactions cannot be bigger than %d\n",
>> + MAX_WR_XACTIONS_MASK);
>> + return -EINVAL;
>> + }
>> +
>> + if (mgmtdev->max_rd_xactions > MAX_RD_XACTIONS_MASK) {
>> + dev_err(&mgmtdev->pdev->dev,
>> + "max_rd_xactions cannot be bigger than %d\n",
>> + MAX_RD_XACTIONS_MASK);
>> + return -EINVAL;
>> + }
>> +
>> + for (i = 0; i < mgmtdev->dma_channels; i++) {
>> + if (mgmtdev->priority[i] > 1) {
>> + dev_err(&mgmtdev->pdev->dev, "priority can be 0 or
>> 1\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (mgmtdev->weight[i] > MAX_CHANNEL_WEIGHT) {
>> + dev_err(&mgmtdev->pdev->dev,
>> + "max value of weight can be %d.\n",
>> + MAX_CHANNEL_WEIGHT);
>> + return -EINVAL;
>> + }
>> +
>> + /* weight needs to be at least one */
>> + if (mgmtdev->weight[i] == 0)
>> + mgmtdev->weight[i] = 1;
>> + }
>> +
>> + pm_runtime_get_sync(&mgmtdev->pdev->dev);
>> + val = readl(mgmtdev->virtaddr + MAX_BUS_REQ_LEN_OFFSET);
>> + val &= ~(MAX_BUS_REQ_LEN_MASK << MAX_BUS_WR_REQ_BIT_POS);
>
>> + val |= (mgmtdev->max_write_request << MAX_BUS_WR_REQ_BIT_POS);
>
> Ditto.
ok
>
>> + val &= ~(MAX_BUS_REQ_LEN_MASK);
>
> Ditto.
ok
>
>> + val |= (mgmtdev->max_read_request);
>
> Ditto.
ok
>
>> + writel(val, mgmtdev->virtaddr + MAX_BUS_REQ_LEN_OFFSET);
>> +
>> + val = readl(mgmtdev->virtaddr + MAX_XACTIONS_OFFSET);
>> + val &= ~(MAX_WR_XACTIONS_MASK << MAX_WR_XACTIONS_BIT_POS);
>
>> + val |= (mgmtdev->max_wr_xactions << MAX_WR_XACTIONS_BIT_POS);
>> + val &= ~(MAX_RD_XACTIONS_MASK);
>> + val |= (mgmtdev->max_rd_xactions);
>
> Ditto for all 3 above.
alright
>
>> + writel(val, mgmtdev->virtaddr + MAX_XACTIONS_OFFSET);
>> +
>> + mgmtdev->hw_version = readl(mgmtdev->virtaddr + HW_VERSION_OFFSET);
>> + mgmtdev->hw_version_major = (mgmtdev->hw_version >> 28) & 0xF;
>> + mgmtdev->hw_version_minor = (mgmtdev->hw_version >> 16) & 0xF;
>> +
>> + for (i = 0; i < mgmtdev->dma_channels; i++) {
>> + val = readl(mgmtdev->virtaddr + QOS_N_OFFSET + (4 * i));
>
> Ditto.
>
>> + val &= ~(1 << PRIORITY_BIT_POS);
>> + val |= ((mgmtdev->priority[i] & 0x1) << PRIORITY_BIT_POS);
>> + val &= ~(WEIGHT_MASK << WRR_BIT_POS);
>> + val |= ((mgmtdev->weight[i] & WEIGHT_MASK) << WRR_BIT_POS);
>> + writel(val, mgmtdev->virtaddr + QOS_N_OFFSET + (4 * i));
>
> Ditto.
>
>> + }
>> +
>> + val = readl(mgmtdev->virtaddr + CHRESET_TIMEOUT_OFFSET);
>> + val &= ~CHRESET_TIMEOUUT_MASK;
>
> Look here, you use it like it intuitively feels.
>
>> + val |= (mgmtdev->chreset_timeout_cycles & CHRESET_TIMEOUUT_MASK);
>
> But here…
>
>> + writel(val, mgmtdev->virtaddr + CHRESET_TIMEOUT_OFFSET);
>> +
>> + pm_runtime_mark_last_busy(&mgmtdev->pdev->dev);
>> + pm_runtime_put_autosuspend(&mgmtdev->pdev->dev);
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(hidma_mgmt_setup);
>> +
>> +static int hidma_mgmt_probe(struct platform_device *pdev)
>> +{
>> + struct hidma_mgmt_dev *mgmtdev;
>> + struct resource *res;
>> + void __iomem *virtaddr;
>> + int irq;
>> + int rc;
>> + u32 val;
>> +
>> + pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
>> + pm_runtime_use_autosuspend(&pdev->dev);
>> + pm_runtime_set_active(&pdev->dev);
>> + pm_runtime_enable(&pdev->dev);
>> + pm_runtime_get_sync(&pdev->dev);
>
> +empty line
added a new line for you. I don't know why.
>
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + virtaddr = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(virtaddr)) {
>> + rc = -ENOMEM;
>> + goto out;
>> + }
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq < 0) {
>> + dev_err(&pdev->dev, "irq resources not found\n");
>> + rc = irq;
>> + goto out;
>> + }
>> +
>> + mgmtdev = devm_kzalloc(&pdev->dev, sizeof(*mgmtdev), GFP_KERNEL);
>> + if (!mgmtdev) {
>> + rc = -ENOMEM;
>> + goto out;
>> + }
>> +
>> + mgmtdev->pdev = pdev;
>> + mgmtdev->addrsize = resource_size(res);
>> + mgmtdev->virtaddr = virtaddr;
>> +
>> + rc = device_property_read_u32(&pdev->dev, "dma-channels",
>> + &mgmtdev->dma_channels);
>> + if (rc) {
>> + dev_err(&pdev->dev, "number of channels missing\n");
>> + goto out;
>> + }
>> +
>> + rc = device_property_read_u32(&pdev->dev,
>> + "channel-reset-timeout-cycles",
>> + &mgmtdev->chreset_timeout_cycles);
>> + if (rc) {
>> + dev_err(&pdev->dev, "channel reset timeout missing\n");
>> + goto out;
>> + }
>> +
>> + rc = device_property_read_u32(&pdev->dev, "max-write-burst-bytes",
>> + &mgmtdev->max_write_request);
>> + if (rc) {
>> + dev_err(&pdev->dev, "max-write-burst-bytes missing\n");
>> + goto out;
>> + }
>> +
>> + rc = device_property_read_u32(&pdev->dev, "max-read-burst-bytes",
>> + &mgmtdev->max_read_request);
>> + if (rc) {
>> + dev_err(&pdev->dev, "max-read-burst-bytes missing\n");
>> + goto out;
>> + }
>> +
>> + rc = device_property_read_u32(&pdev->dev, "max-write-transactions",
>> + &mgmtdev->max_wr_xactions);
>> + if (rc) {
>> + dev_err(&pdev->dev, "max-write-transactions missing\n");
>> + goto out;
>> + }
>> +
>> + rc = device_property_read_u32(&pdev->dev, "max-read-transactions",
>> + &mgmtdev->max_rd_xactions);
>> + if (rc) {
>> + dev_err(&pdev->dev, "max-read-transactions missing\n");
>> + goto out;
>> + }
>> +
>> + mgmtdev->priority = devm_kcalloc(&pdev->dev,
>> + mgmtdev->dma_channels, sizeof(*mgmtdev->priority),
>> GFP_KERNEL);
>> + if (!mgmtdev->priority) {
>> + rc = -ENOMEM;
>> + goto out;
>> + }
>> +
>> + mgmtdev->weight = devm_kcalloc(&pdev->dev,
>> + mgmtdev->dma_channels, sizeof(*mgmtdev->weight),
>> GFP_KERNEL);
>> + if (!mgmtdev->weight) {
>> + rc = -ENOMEM;
>> + goto out;
>> + }
>> +
>> + rc = device_property_read_u32_array(&pdev->dev, "channel-priority",
>> + mgmtdev->priority, mgmtdev->dma_channels);
>> + if (rc) {
>> + dev_err(&pdev->dev, "channel-priority missing\n");
>> + goto out;
>> + }
>> +
>> + rc = device_property_read_u32_array(&pdev->dev, "channel-weight",
>> + mgmtdev->weight, mgmtdev->dma_channels);
>> + if (rc) {
>> + dev_err(&pdev->dev, "channel-weight missing\n");
>> + goto out;
>> + }
>> +
>> + rc = hidma_mgmt_setup(mgmtdev);
>> + if (rc) {
>> + dev_err(&pdev->dev, "setup failed\n");
>> + goto out;
>> + }
>> +
>> + /* start the HW */
>> + val = readl(mgmtdev->virtaddr + CFG_OFFSET);
>> + val |= 1;
>> + writel(val, mgmtdev->virtaddr + CFG_OFFSET);
>> +
>> + rc = hidma_mgmt_init_sys(mgmtdev);
>> + if (rc) {
>> + dev_err(&pdev->dev, "sysfs setup failed\n");
>> + goto out;
>> + }
>> +
>> + dev_info(&pdev->dev,
>> + "HW rev: %d.%d @ %pa with %d physical channels\n",
>> + mgmtdev->hw_version_major, mgmtdev->hw_version_minor,
>> + &res->start, mgmtdev->dma_channels);
>> +
>> + platform_set_drvdata(pdev, mgmtdev);
>> + pm_runtime_mark_last_busy(&pdev->dev);
>> + pm_runtime_put_autosuspend(&pdev->dev);
>> + return 0;
>
>> +out:
>> + pm_runtime_disable(&pdev->dev);
>> + pm_runtime_put_sync_suspend(&pdev->dev);
>
> I'm not sure the sequence is logically correct, though it might work.
>
reversed
>> + return rc;
>> +}
>> +
>> +#if IS_ENABLED(CONFIG_ACPI)
>> +static const struct acpi_device_id hidma_mgmt_acpi_ids[] = {
>> + {"QCOM8060"},
>> + {},
>> +};
>> +#endif
>> +
>> +static const struct of_device_id hidma_mgmt_match[] = {
>> + { .compatible = "qcom,hidma-mgmt-1.0", },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, hidma_mgmt_match);
>> +
>> +static struct platform_driver hidma_mgmt_driver = {
>> + .probe = hidma_mgmt_probe,
>> + .driver = {
>> + .name = "hidma-mgmt",
>> + .of_match_table = hidma_mgmt_match,
>> + .acpi_match_table = ACPI_PTR(hidma_mgmt_acpi_ids),
>> + },
>> +};
>> +module_platform_driver(hidma_mgmt_driver);
>> +MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/dma/qcom/hidma_mgmt.h b/drivers/dma/qcom/hidma_mgmt.h
>> new file mode 100644
>> index 0000000..04340ff
>> --- /dev/null
>> +++ b/drivers/dma/qcom/hidma_mgmt.h
>> @@ -0,0 +1,38 @@
>> +/*
>> + * Qualcomm Technologies HIDMA Management common header
>> + *
>> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 and
>> + * only 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.
>> + */
>> +
>> +struct hidma_mgmt_dev {
>> + u8 hw_version_major;
>> + u8 hw_version_minor;
>> +
>> + u32 max_wr_xactions;
>> + u32 max_rd_xactions;
>> + u32 max_write_request;
>> + u32 max_read_request;
>> + u32 dma_channels;
>> + u32 chreset_timeout_cycles;
>> + u32 hw_version;
>> + u32 *priority;
>> + u32 *weight;
>> +
>> + /* Hardware device constants */
>> + void __iomem *virtaddr;
>> + resource_size_t addrsize;
>> +
>> + struct platform_device *pdev;
>> +};
>> +
>> +int hidma_mgmt_init_sys(struct hidma_mgmt_dev *dev);
>> +int hidma_mgmt_setup(struct hidma_mgmt_dev *mgmtdev);
>> diff --git a/drivers/dma/qcom/hidma_mgmt_sys.c
>> b/drivers/dma/qcom/hidma_mgmt_sys.c
>> new file mode 100644
>> index 0000000..70d324e
>> --- /dev/null
>> +++ b/drivers/dma/qcom/hidma_mgmt_sys.c
>> @@ -0,0 +1,231 @@
>> +/*
>> + * Qualcomm Technologies HIDMA Management SYS interface
>> + *
>> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 and
>> + * only 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 <linux/sysfs.h>
>> +#include <linux/platform_device.h>
>> +
>> +#include "hidma_mgmt.h"
>> +
>> +struct fileinfo {
>> + char *name;
>> + int mode;
>> + int (*get)(struct hidma_mgmt_dev *mdev);
>> + int (*set)(struct hidma_mgmt_dev *mdev, u64 val);
>> +};
>> +
>> +#define IMPLEMENT_GETSET(name) \
>> +static int get_##name(struct hidma_mgmt_dev *mdev) \
>> +{ \
>> + return mdev->name; \
>> +} \
>> +static int set_##name(struct hidma_mgmt_dev *mdev, u64 val) \
>> +{ \
>> + u64 tmp; \
>> + int rc; \
>> + \
>> + tmp = mdev->name; \
>> + mdev->name = val; \
>> + rc = hidma_mgmt_setup(mdev); \
>> + if (rc) \
>> + mdev->name = tmp; \
>> + return rc; \
>> +}
>> +
>> +#define DECLARE_ATTRIBUTE(name, mode) \
>> + {#name, mode, get_##name, set_##name}
>> +
>> +IMPLEMENT_GETSET(hw_version_major)
>> +IMPLEMENT_GETSET(hw_version_minor)
>> +IMPLEMENT_GETSET(max_wr_xactions)
>> +IMPLEMENT_GETSET(max_rd_xactions)
>> +IMPLEMENT_GETSET(max_write_request)
>> +IMPLEMENT_GETSET(max_read_request)
>> +IMPLEMENT_GETSET(dma_channels)
>> +IMPLEMENT_GETSET(chreset_timeout_cycles)
>> +
>> +static int set_priority(struct hidma_mgmt_dev *mdev, unsigned int i, u64
>> val)
>> +{
>> + u64 tmp;
>> + int rc;
>> +
>> + if (i > mdev->dma_channels)
>> + return -EINVAL;
>> +
>> + tmp = mdev->priority[i];
>> + mdev->priority[i] = val;
>> + rc = hidma_mgmt_setup(mdev);
>> + if (rc)
>> + mdev->priority[i] = tmp;
>> + return rc;
>> +}
>> +
>> +static int set_weight(struct hidma_mgmt_dev *mdev, unsigned int i, u64 val)
>> +{
>> + u64 tmp;
>> + int rc;
>> +
>> + if (i > mdev->dma_channels)
>> + return -EINVAL;
>> +
>> + tmp = mdev->weight[i];
>> + mdev->weight[i] = val;
>> + rc = hidma_mgmt_setup(mdev);
>> + if (rc)
>> + mdev->weight[i] = tmp;
>> + return rc;
>> +}
>> +
>> +static struct fileinfo files[] = {
>
> Perhaps hidma_mgmt_files ?
done
>
>> + DECLARE_ATTRIBUTE(hw_version_major, S_IRUGO),
>> + DECLARE_ATTRIBUTE(hw_version_minor, S_IRUGO),
>> + DECLARE_ATTRIBUTE(dma_channels, S_IRUGO),
>> + DECLARE_ATTRIBUTE(chreset_timeout_cycles, S_IRUGO),
>> + DECLARE_ATTRIBUTE(max_wr_xactions, (S_IRUGO|S_IWUGO)),
>> + DECLARE_ATTRIBUTE(max_rd_xactions, (S_IRUGO|S_IWUGO)),
>> + DECLARE_ATTRIBUTE(max_write_request, (S_IRUGO|S_IWUGO)),
>> + DECLARE_ATTRIBUTE(max_read_request, (S_IRUGO|S_IWUGO)),
>> +};
>> +
>> +static ssize_t show_values(struct device *dev, struct device_attribute
>> *attr,
>> + char *buf)
>> +{
>> + struct platform_device *pdev = to_platform_device(dev);
>> + struct hidma_mgmt_dev *mdev = platform_get_drvdata(pdev);
>> + unsigned int i;
>> +
I'll initialize buf as
buf[0] = 0;
here.
>> + for (i = 0; i < ARRAY_SIZE(files); i++) {
>> + if (strcmp(attr->attr.name, files[i].name) == 0) {
>> + sprintf(buf, "%d\n", files[i].get(mdev));
>> + goto done;
>> + }
>> + }
>> +
>> + for (i = 0; i < mdev->dma_channels; i++) {
>> + char name[30];
>> +
>> + sprintf(name, "channel%d_priority", i);
>> + if (strcmp(attr->attr.name, name) == 0) {
>> + sprintf(buf, "%d\n", mdev->priority[i]);
>> + goto done;
>> + }
>> +
>> + sprintf(name, "channel%d_weight", i);
>> + if (strcmp(attr->attr.name, name) == 0) {
>> + sprintf(buf, "%d\n", mdev->weight[i]);
>> + goto done;
>> + }
>> + }
>> +
>> +done:
>> + return strlen(buf);
>
> buf might be uninitialized here. Have you got any warning from compiler?
>
>> +}
>> +
>> +static ssize_t set_values(struct device *dev, struct device_attribute
>> *attr,
>> + const char *buf, size_t count)
>> +{
>> + struct platform_device *pdev = to_platform_device(dev);
>> + struct hidma_mgmt_dev *mdev = platform_get_drvdata(pdev);
>> + unsigned long tmp;
>> + unsigned int i;
>> + int rc;
>> +
>> + rc = kstrtoul(buf, 0, &tmp);
>> + if (rc)
>> + return rc;
>> +
>> + for (i = 0; i < ARRAY_SIZE(files); i++) {
>> + if (strcmp(attr->attr.name, files[i].name) == 0) {
>> + rc = files[i].set(mdev, tmp);
>> + if (rc)
>> + return rc;
>> +
>> + goto done;
>> + }
>> + }
>> +
>> + for (i = 0; i < mdev->dma_channels; i++) {
>> + char name[30];
>> +
>> + sprintf(name, "channel%d_priority", i);
>> + if (strcmp(attr->attr.name, name) == 0) {
>> + rc = set_priority(mdev, i, tmp);
>> + if (rc)
>> + return rc;
>> + goto done;
>> + }
>> +
>> + sprintf(name, "channel%d_weight", i);
>> + if (strcmp(attr->attr.name, name) == 0) {
>> + rc = set_weight(mdev, i, tmp);
>> + if (rc)
>> + return rc;
>> + }
>> + }
>> +done:
>> + return count;
>> +}
>> +
>> +static int create_sysfs_entry(struct hidma_mgmt_dev *dev, char *name, int
>> mode)
>> +{
>> + struct device_attribute *attrs;
>> + char *name_copy;
>> +
>> + attrs = devm_kmalloc(&dev->pdev->dev,
>> + sizeof(struct device_attribute), GFP_KERNEL);
>> + if (!attrs)
>> + return -ENOMEM;
>> +
>> + name_copy = devm_kstrdup(&dev->pdev->dev, name, GFP_KERNEL);
>> + if (!name_copy)
>> + return -ENOMEM;
>> +
>> + attrs->attr.name = name_copy;
>> + attrs->attr.mode = mode;
>> + attrs->show = show_values;
>> + attrs->store = set_values;
>> + sysfs_attr_init(&attrs->attr);
>> +
>> + return device_create_file(&dev->pdev->dev, attrs);
>> +}
>> +
>> +
>
> Extra empty line.
>
Removed
>> +int hidma_mgmt_init_sys(struct hidma_mgmt_dev *dev)
>> +{
>> + unsigned int i;
>> + int rc;
>> +
>> + for (i = 0; i < ARRAY_SIZE(files); i++) {
>> + rc = create_sysfs_entry(dev, files[i].name, files[i].mode);
>> + if (rc)
>> + return rc;
>> + }
>> +
>
> Can it be like
>
> /sys/…/DEVICExx/
> channelYY/
> attr1
> attr2
> …
>
> ?
I'll work on it. I didn't know that you are allowed to create subdirectories
in sysfs. I was just creating attributes to keep it simple. But, your
suggestion is cleaner.
>
> I think it will be easier to handle in code and from user. (Similar
> way DMAEngine API does for slave DMA devices)
Now, the good stuff. Can you clarify your comment? I didn't understand it.
>
>> + for (i = 0; i < dev->dma_channels; i++) {
>> + char name[30];
>> +
>> + sprintf(name, "channel%d_priority", i);
>> + rc = create_sysfs_entry(dev, name, (S_IRUGO|S_IWUGO));
>> + if (rc)
>> + return rc;
>> +
>> + sprintf(name, "channel%d_weight", i);
>> + rc = create_sysfs_entry(dev, name, (S_IRUGO|S_IWUGO));
>> + if (rc)
>> + return rc;
>> + }
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(hidma_mgmt_init_sys);
>
> --
> With Best Regards,
> Andy Shevchenko
>
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