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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 13:39:22 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 13:39:22 -0700 |
commit | f678d6da749983791850876e3421e7c48a0a7127 (patch) | |
tree | 553f818ef8e73bf9d6b1e53bdf623240c1279ffb /drivers/w1/slaves/w1_ds2408.c | |
parent | Merge tag 'char-misc-5.2-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc (diff) | |
parent | intel_th: msu: Add current window tracking (diff) | |
download | linux-dev-f678d6da749983791850876e3421e7c48a0a7127.tar.xz linux-dev-f678d6da749983791850876e3421e7c48a0a7127.zip |
Merge tag 'char-misc-5.2-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc update part 2 from Greg KH:
"Here is the "real" big set of char/misc driver patches for 5.2-rc1
Loads of different driver subsystem stuff in here, all over the places:
- thunderbolt driver updates
- habanalabs driver updates
- nvmem driver updates
- extcon driver updates
- intel_th driver updates
- mei driver updates
- coresight driver updates
- soundwire driver cleanups and updates
- fastrpc driver updates
- other minor driver updates
- chardev minor fixups
Feels like this tree is getting to be a dumping ground of "small
driver subsystems" these days. Which is fine with me, if it makes
things easier for those subsystem maintainers.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.2-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits)
intel_th: msu: Add current window tracking
intel_th: msu: Add a sysfs attribute to trigger window switch
intel_th: msu: Correct the block wrap detection
intel_th: Add switch triggering support
intel_th: gth: Factor out trace start/stop
intel_th: msu: Factor out pipeline draining
intel_th: msu: Switch over to scatterlist
intel_th: msu: Replace open-coded list_{first,last,next}_entry variants
intel_th: Only report useful IRQs to subdevices
intel_th: msu: Start handling IRQs
intel_th: pci: Use MSI interrupt signalling
intel_th: Communicate IRQ via resource
intel_th: Add "rtit" source device
intel_th: Skip subdevices if their MMIO is missing
intel_th: Rework resource passing between glue layers and core
intel_th: SPDX-ify the documentation
intel_th: msu: Fix single mode with IOMMU
coresight: funnel: Support static funnel
dt-bindings: arm: coresight: Unify funnel DT binding
coresight: replicator: Add new device id for static replicator
...
Diffstat (limited to 'drivers/w1/slaves/w1_ds2408.c')
-rw-r--r-- | drivers/w1/slaves/w1_ds2408.c | 76 |
1 files changed, 39 insertions, 37 deletions
diff --git a/drivers/w1/slaves/w1_ds2408.c b/drivers/w1/slaves/w1_ds2408.c index b535d5ec35b6..92e8f0755b9a 100644 --- a/drivers/w1/slaves/w1_ds2408.c +++ b/drivers/w1/slaves/w1_ds2408.c @@ -138,14 +138,37 @@ static ssize_t status_control_read(struct file *filp, struct kobject *kobj, W1_F29_REG_CONTROL_AND_STATUS, buf); } +#ifdef fCONFIG_W1_SLAVE_DS2408_READBACK +static bool optional_read_back_valid(struct w1_slave *sl, u8 expected) +{ + u8 w1_buf[3]; + + if (w1_reset_resume_command(sl->master)) + return false; + + w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; + w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE; + w1_buf[2] = 0; + + w1_write_block(sl->master, w1_buf, 3); + + return (w1_read_8(sl->master) == expected); +} +#else +static bool optional_read_back_valid(struct w1_slave *sl, u8 expected) +{ + return true; +} +#endif + static ssize_t output_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct w1_slave *sl = kobj_to_w1_slave(kobj); u8 w1_buf[3]; - u8 readBack; unsigned int retries = W1_F29_RETRIES; + ssize_t bytes_written = -EIO; if (count != 1 || off != 0) return -EFAULT; @@ -155,54 +178,33 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj, dev_dbg(&sl->dev, "mutex locked"); if (w1_reset_select_slave(sl)) - goto error; + goto out; - while (retries--) { + do { w1_buf[0] = W1_F29_FUNC_CHANN_ACCESS_WRITE; w1_buf[1] = *buf; w1_buf[2] = ~(*buf); - w1_write_block(sl->master, w1_buf, 3); - readBack = w1_read_8(sl->master); + w1_write_block(sl->master, w1_buf, 3); - if (readBack != W1_F29_SUCCESS_CONFIRM_BYTE) { - if (w1_reset_resume_command(sl->master)) - goto error; - /* try again, the slave is ready for a command */ - continue; + if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE && + optional_read_back_valid(sl, *buf)) { + bytes_written = 1; + goto out; } -#ifdef CONFIG_W1_SLAVE_DS2408_READBACK - /* here the master could read another byte which - would be the PIO reg (the actual pin logic state) - since in this driver we don't know which pins are - in and outs, there's no value to read the state and - compare. with (*buf) so end this command abruptly: */ if (w1_reset_resume_command(sl->master)) - goto error; + goto out; /* unrecoverable error */ + /* try again, the slave is ready for a command */ + } while (--retries); - /* go read back the output latches */ - /* (the direct effect of the write above) */ - w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; - w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE; - w1_buf[2] = 0; - w1_write_block(sl->master, w1_buf, 3); - /* read the result of the READ_PIO_REGS command */ - if (w1_read_8(sl->master) == *buf) -#endif - { - /* success! */ - mutex_unlock(&sl->master->bus_mutex); - dev_dbg(&sl->dev, - "mutex unlocked, retries:%d", retries); - return 1; - } - } -error: +out: mutex_unlock(&sl->master->bus_mutex); - dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); - return -EIO; + dev_dbg(&sl->dev, "%s, mutex unlocked retries:%d\n", + (bytes_written > 0) ? "succeeded" : "error", retries); + + return bytes_written; } |