From d1dcd678257603e71cf3f3d84c70e2b6f0f14bb8 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 21 Jun 2018 12:34:22 +1000 Subject: [PATCH] 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 --- drivers/fsi/fsi-core.c | 264 +++++++++++++++++++++++++++++++++-------- 1 file changed, 213 insertions(+), 51 deletions(-) diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c index faa1760a5a40..dea5bd48acc5 100644 --- a/drivers/fsi/fsi-core.c +++ b/drivers/fsi/fsi-core.c @@ -11,6 +11,11 @@ * 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. + * + * TODO: + * - Rework topology + * - s/chip_id/chip_loc + * - s/cfam/chip (cfam_id -> chip_id etc...) */ #include @@ -21,6 +26,9 @@ #include #include #include +#include +#include +#include #include "fsi-master.h" @@ -78,8 +86,11 @@ static DEFINE_IDA(master_ida); struct fsi_slave { struct device dev; struct fsi_master *master; - int id; - int link; + struct cdev cdev; + int cdev_idx; + int id; /* FSI address */ + int link; /* FSI link# */ + u32 cfam_id; int chip_id; uint32_t size; /* size of slave address space */ u8 t_send_delay; @@ -607,29 +618,6 @@ static const struct bin_attribute fsi_slave_raw_attr = { .write = fsi_slave_sysfs_raw_write, }; -static ssize_t fsi_slave_sysfs_term_write(struct file *file, - struct kobject *kobj, struct bin_attribute *attr, - char *buf, loff_t off, size_t count) -{ - struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); - struct fsi_master *master = slave->master; - - if (!master->term) - return -ENODEV; - - master->term(master, slave->link, slave->id); - return count; -} - -static const struct bin_attribute fsi_slave_term_attr = { - .attr = { - .name = "term", - .mode = 0200, - }, - .size = 0, - .write = fsi_slave_sysfs_term_write, -}; - static void fsi_slave_release(struct device *dev) { struct fsi_slave *slave = to_fsi_slave(dev); @@ -682,6 +670,127 @@ static struct device_node *fsi_slave_find_of_node(struct fsi_master *master, return NULL; } +static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count, + loff_t *offset) +{ + struct fsi_slave *slave = filep->private_data; + size_t total_len, read_len; + loff_t off = *offset; + ssize_t rc; + + if (off < 0) + return -EINVAL; + + if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) + return -EINVAL; + + for (total_len = 0; total_len < count; total_len += read_len) { + __be32 data; + + read_len = min_t(size_t, count, 4); + read_len -= off & 0x3; + + rc = fsi_slave_read(slave, off, &data, read_len); + if (rc) + goto fail; + rc = copy_to_user(buf + total_len, &data, read_len); + if (rc) { + rc = -EFAULT; + goto fail; + } + off += read_len; + } + rc = count; + fail: + *offset = off; + return count; +} + +static ssize_t cfam_write(struct file *filep, const char __user *buf, + size_t count, loff_t *offset) +{ + struct fsi_slave *slave = filep->private_data; + size_t total_len, write_len; + loff_t off = *offset; + ssize_t rc; + + + if (off < 0) + return -EINVAL; + + if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) + return -EINVAL; + + for (total_len = 0; total_len < count; total_len += write_len) { + __be32 data; + + write_len = min_t(size_t, count, 4); + write_len -= off & 0x3; + + rc = copy_from_user(&data, buf + total_len, write_len); + if (rc) { + rc = -EFAULT; + goto fail; + } + rc = fsi_slave_write(slave, off, &data, write_len); + if (rc) + goto fail; + off += write_len; + } + rc = count; + fail: + *offset = off; + return count; +} + +static loff_t cfam_llseek(struct file *file, loff_t offset, int whence) +{ + switch (whence) { + case SEEK_CUR: + break; + case SEEK_SET: + file->f_pos = offset; + break; + default: + return -EINVAL; + } + + return offset; +} + +static int cfam_open(struct inode *inode, struct file *file) +{ + struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev); + + file->private_data = slave; + + return 0; +} + +static const struct file_operations cfam_fops = { + .owner = THIS_MODULE, + .open = cfam_open, + .llseek = cfam_llseek, + .read = cfam_read, + .write = cfam_write, +}; + +static ssize_t send_term_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct fsi_slave *slave = to_fsi_slave(dev); + struct fsi_master *master = slave->master; + + if (!master->term) + return -ENODEV; + + master->term(master, slave->link, slave->id); + return count; +} + +static DEVICE_ATTR_WO(send_term); + static ssize_t slave_send_echo_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -737,6 +846,52 @@ static ssize_t chip_id_show(struct device *dev, static DEVICE_ATTR_RO(chip_id); +static ssize_t cfam_id_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct fsi_slave *slave = to_fsi_slave(dev); + + return sprintf(buf, "0x%x\n", slave->cfam_id); +} + +static DEVICE_ATTR_RO(cfam_id); + +static struct attribute *cfam_attr[] = { + &dev_attr_send_echo_delays.attr, + &dev_attr_chip_id.attr, + &dev_attr_cfam_id.attr, + &dev_attr_send_term.attr, + NULL, +}; + +static const struct attribute_group cfam_attr_group = { + .attrs = cfam_attr, +}; + +static const struct attribute_group *cfam_attr_groups[] = { + &cfam_attr_group, + NULL, +}; + +static char *cfam_devnode(struct device *dev, umode_t *mode, + kuid_t *uid, kgid_t *gid) +{ + struct fsi_slave *slave = to_fsi_slave(dev); + +#ifdef CONFIG_FSI_NEW_DEV_NODE + return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx); +#else + return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx); +#endif +} + +static const struct device_type cfam_type = { + .name = "cfam", + .devnode = cfam_devnode, + .groups = cfam_attr_groups +}; + static char *fsi_cdev_devnode(struct device *dev, umode_t *mode, kuid_t *uid, kgid_t *gid) { @@ -808,7 +963,7 @@ EXPORT_SYMBOL_GPL(fsi_free_minor); static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) { - uint32_t chip_id; + uint32_t cfam_id; struct fsi_slave *slave; uint8_t crc; __be32 data, llmode; @@ -826,17 +981,17 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) link, id, rc); return -ENODEV; } - chip_id = be32_to_cpu(data); + cfam_id = be32_to_cpu(data); - crc = crc4(0, chip_id, 32); + crc = crc4(0, cfam_id, 32); if (crc) { - dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n", + dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n", link, id); return -EIO; } dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", - chip_id, master->idx, link, id); + cfam_id, master->idx, link, id); /* If we're behind a master that doesn't provide a self-running bus * clock, put the slave into async mode @@ -859,10 +1014,14 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) if (!slave) return -ENOMEM; - slave->master = master; + dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); + slave->dev.type = &cfam_type; slave->dev.parent = &master->dev; slave->dev.of_node = fsi_slave_find_of_node(master, link, id); slave->dev.release = fsi_slave_release; + device_initialize(&slave->dev); + slave->cfam_id = cfam_id; + slave->master = master; slave->link = link; slave->id = id; slave->size = FSI_SLAVE_SIZE_23b; @@ -877,6 +1036,21 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) slave->chip_id = prop; } + + /* Allocate a minor in the FSI space */ + rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt, + &slave->cdev_idx); + if (rc) + goto err_free; + + /* Create chardev for userspace access */ + cdev_init(&slave->cdev, &cfam_fops); + rc = cdev_device_add(&slave->cdev, &slave->dev); + if (rc) { + dev_err(&slave->dev, "Error %d creating slave device\n", rc); + goto err_free; + } + rc = fsi_slave_set_smode(slave); if (rc) { dev_warn(&master->dev, @@ -890,30 +1064,11 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) slave->t_send_delay, slave->t_echo_delay); - dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); - rc = device_register(&slave->dev); - if (rc < 0) { - dev_warn(&master->dev, "failed to create slave device: %d\n", - rc); - put_device(&slave->dev); - return rc; - } - + /* Legacy raw file -> to be removed */ rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); if (rc) dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); - rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr); - if (rc) - dev_warn(&slave->dev, "failed to create term attr: %d\n", rc); - - rc = device_create_file(&slave->dev, &dev_attr_send_echo_delays); - if (rc) - dev_warn(&slave->dev, "failed to create delay attr: %d\n", rc); - - rc = device_create_file(&slave->dev, &dev_attr_chip_id); - if (rc) - dev_warn(&slave->dev, "failed to create chip id: %d\n", rc); rc = fsi_slave_scan(slave); if (rc) @@ -921,6 +1076,10 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) rc); return rc; + + err_free: + put_device(&slave->dev); + return rc; } /* FSI master support */ @@ -1029,7 +1188,10 @@ static int fsi_slave_remove_device(struct device *dev, void *arg) static int fsi_master_remove_slave(struct device *dev, void *arg) { + struct fsi_slave *slave = to_fsi_slave(dev); + device_for_each_child(dev, NULL, fsi_slave_remove_device); + cdev_device_del(&slave->cdev, &slave->dev); put_device(dev); return 0; }