fsi: Add cfam char devices
This aims to deprecate the "raw" sysfs file used for directly accessing the CFAM and instead use a char device like the other sub drivers. Since it reworks the slave creation code and adds a cfam device type, we also use the opportunity to convert the attributes to attribute groups and add a couple more. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>hifive-unleashed-5.1
Benjamin Herrenschmidt
parent
d8f4587655
commit
d1dcd67825
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@ -11,6 +11,11 @@
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* TODO:
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* - Rework topology
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* - s/chip_id/chip_loc
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* - s/cfam/chip (cfam_id -> chip_id etc...)
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*/
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#include <linux/crc4.h>
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@ -21,6 +26,9 @@
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#include <linux/of.h>
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#include <linux/slab.h>
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#include <linux/bitops.h>
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#include <linux/cdev.h>
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#include <linux/fs.h>
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#include <linux/uaccess.h>
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#include "fsi-master.h"
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@ -78,8 +86,11 @@ static DEFINE_IDA(master_ida);
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struct fsi_slave {
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struct device dev;
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struct fsi_master *master;
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int id;
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int link;
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struct cdev cdev;
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int cdev_idx;
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int id; /* FSI address */
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int link; /* FSI link# */
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u32 cfam_id;
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int chip_id;
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uint32_t size; /* size of slave address space */
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u8 t_send_delay;
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@ -607,29 +618,6 @@ static const struct bin_attribute fsi_slave_raw_attr = {
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.write = fsi_slave_sysfs_raw_write,
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};
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static ssize_t fsi_slave_sysfs_term_write(struct file *file,
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struct kobject *kobj, struct bin_attribute *attr,
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char *buf, loff_t off, size_t count)
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{
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struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
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struct fsi_master *master = slave->master;
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if (!master->term)
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return -ENODEV;
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master->term(master, slave->link, slave->id);
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return count;
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}
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static const struct bin_attribute fsi_slave_term_attr = {
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.attr = {
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.name = "term",
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.mode = 0200,
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},
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.size = 0,
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.write = fsi_slave_sysfs_term_write,
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};
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static void fsi_slave_release(struct device *dev)
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{
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struct fsi_slave *slave = to_fsi_slave(dev);
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@ -682,6 +670,127 @@ static struct device_node *fsi_slave_find_of_node(struct fsi_master *master,
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return NULL;
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}
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static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count,
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loff_t *offset)
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{
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struct fsi_slave *slave = filep->private_data;
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size_t total_len, read_len;
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loff_t off = *offset;
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ssize_t rc;
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if (off < 0)
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return -EINVAL;
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if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
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return -EINVAL;
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for (total_len = 0; total_len < count; total_len += read_len) {
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__be32 data;
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read_len = min_t(size_t, count, 4);
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read_len -= off & 0x3;
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rc = fsi_slave_read(slave, off, &data, read_len);
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if (rc)
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goto fail;
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rc = copy_to_user(buf + total_len, &data, read_len);
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if (rc) {
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rc = -EFAULT;
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goto fail;
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}
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off += read_len;
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}
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rc = count;
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fail:
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*offset = off;
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return count;
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}
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static ssize_t cfam_write(struct file *filep, const char __user *buf,
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size_t count, loff_t *offset)
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{
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struct fsi_slave *slave = filep->private_data;
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size_t total_len, write_len;
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loff_t off = *offset;
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ssize_t rc;
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if (off < 0)
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return -EINVAL;
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if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
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return -EINVAL;
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for (total_len = 0; total_len < count; total_len += write_len) {
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__be32 data;
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write_len = min_t(size_t, count, 4);
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write_len -= off & 0x3;
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rc = copy_from_user(&data, buf + total_len, write_len);
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if (rc) {
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rc = -EFAULT;
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goto fail;
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}
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rc = fsi_slave_write(slave, off, &data, write_len);
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if (rc)
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goto fail;
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off += write_len;
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}
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rc = count;
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fail:
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*offset = off;
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return count;
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}
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static loff_t cfam_llseek(struct file *file, loff_t offset, int whence)
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{
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switch (whence) {
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case SEEK_CUR:
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break;
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case SEEK_SET:
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file->f_pos = offset;
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break;
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default:
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return -EINVAL;
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}
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return offset;
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}
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static int cfam_open(struct inode *inode, struct file *file)
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{
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struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev);
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file->private_data = slave;
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return 0;
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}
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static const struct file_operations cfam_fops = {
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.owner = THIS_MODULE,
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.open = cfam_open,
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.llseek = cfam_llseek,
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.read = cfam_read,
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.write = cfam_write,
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};
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static ssize_t send_term_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct fsi_slave *slave = to_fsi_slave(dev);
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struct fsi_master *master = slave->master;
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if (!master->term)
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return -ENODEV;
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master->term(master, slave->link, slave->id);
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return count;
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}
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static DEVICE_ATTR_WO(send_term);
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static ssize_t slave_send_echo_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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@ -737,6 +846,52 @@ static ssize_t chip_id_show(struct device *dev,
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static DEVICE_ATTR_RO(chip_id);
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static ssize_t cfam_id_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct fsi_slave *slave = to_fsi_slave(dev);
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return sprintf(buf, "0x%x\n", slave->cfam_id);
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}
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static DEVICE_ATTR_RO(cfam_id);
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static struct attribute *cfam_attr[] = {
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&dev_attr_send_echo_delays.attr,
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&dev_attr_chip_id.attr,
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&dev_attr_cfam_id.attr,
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&dev_attr_send_term.attr,
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NULL,
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};
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static const struct attribute_group cfam_attr_group = {
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.attrs = cfam_attr,
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};
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static const struct attribute_group *cfam_attr_groups[] = {
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&cfam_attr_group,
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NULL,
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};
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static char *cfam_devnode(struct device *dev, umode_t *mode,
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kuid_t *uid, kgid_t *gid)
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{
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struct fsi_slave *slave = to_fsi_slave(dev);
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#ifdef CONFIG_FSI_NEW_DEV_NODE
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return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx);
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#else
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return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx);
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#endif
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}
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static const struct device_type cfam_type = {
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.name = "cfam",
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.devnode = cfam_devnode,
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.groups = cfam_attr_groups
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};
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static char *fsi_cdev_devnode(struct device *dev, umode_t *mode,
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kuid_t *uid, kgid_t *gid)
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{
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@ -808,7 +963,7 @@ EXPORT_SYMBOL_GPL(fsi_free_minor);
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static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
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{
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uint32_t chip_id;
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uint32_t cfam_id;
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struct fsi_slave *slave;
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uint8_t crc;
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__be32 data, llmode;
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@ -826,17 +981,17 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
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link, id, rc);
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return -ENODEV;
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}
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chip_id = be32_to_cpu(data);
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cfam_id = be32_to_cpu(data);
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crc = crc4(0, chip_id, 32);
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crc = crc4(0, cfam_id, 32);
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if (crc) {
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dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n",
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dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n",
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link, id);
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return -EIO;
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}
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dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
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chip_id, master->idx, link, id);
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cfam_id, master->idx, link, id);
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/* If we're behind a master that doesn't provide a self-running bus
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* clock, put the slave into async mode
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@ -859,10 +1014,14 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
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if (!slave)
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return -ENOMEM;
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slave->master = master;
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dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
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slave->dev.type = &cfam_type;
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slave->dev.parent = &master->dev;
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slave->dev.of_node = fsi_slave_find_of_node(master, link, id);
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slave->dev.release = fsi_slave_release;
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device_initialize(&slave->dev);
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slave->cfam_id = cfam_id;
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slave->master = master;
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slave->link = link;
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slave->id = id;
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slave->size = FSI_SLAVE_SIZE_23b;
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@ -877,6 +1036,21 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
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slave->chip_id = prop;
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}
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/* Allocate a minor in the FSI space */
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rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt,
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&slave->cdev_idx);
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if (rc)
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goto err_free;
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/* Create chardev for userspace access */
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cdev_init(&slave->cdev, &cfam_fops);
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rc = cdev_device_add(&slave->cdev, &slave->dev);
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if (rc) {
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dev_err(&slave->dev, "Error %d creating slave device\n", rc);
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goto err_free;
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}
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rc = fsi_slave_set_smode(slave);
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if (rc) {
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dev_warn(&master->dev,
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@ -890,30 +1064,11 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
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slave->t_send_delay,
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slave->t_echo_delay);
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dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
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rc = device_register(&slave->dev);
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if (rc < 0) {
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dev_warn(&master->dev, "failed to create slave device: %d\n",
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rc);
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put_device(&slave->dev);
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return rc;
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}
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/* Legacy raw file -> to be removed */
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rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);
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if (rc)
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dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);
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rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr);
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if (rc)
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dev_warn(&slave->dev, "failed to create term attr: %d\n", rc);
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rc = device_create_file(&slave->dev, &dev_attr_send_echo_delays);
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if (rc)
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dev_warn(&slave->dev, "failed to create delay attr: %d\n", rc);
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rc = device_create_file(&slave->dev, &dev_attr_chip_id);
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if (rc)
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dev_warn(&slave->dev, "failed to create chip id: %d\n", rc);
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rc = fsi_slave_scan(slave);
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if (rc)
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@ -921,6 +1076,10 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
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rc);
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return rc;
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err_free:
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put_device(&slave->dev);
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return rc;
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}
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/* FSI master support */
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@ -1029,7 +1188,10 @@ static int fsi_slave_remove_device(struct device *dev, void *arg)
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static int fsi_master_remove_slave(struct device *dev, void *arg)
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{
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struct fsi_slave *slave = to_fsi_slave(dev);
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device_for_each_child(dev, NULL, fsi_slave_remove_device);
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cdev_device_del(&slave->cdev, &slave->dev);
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put_device(dev);
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return 0;
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}
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