Messages in this thread | | | Subject | Re: [PATCH v15 6/9] HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings | From | John Garry <> | Date | Fri, 2 Mar 2018 10:44:46 +0000 |
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On 01/03/2018 19:26, Andy Shevchenko wrote: > On Tue, 2018-02-27 at 00:40 +0800, John Garry wrote: > >> The low-pin-count(LPC) interface of Hip06/Hip07 accesses the >> peripherals in >> I/O port addresses. This patch implements the LPC host controller >> driver >> which perform the I/O operations on the underlying hardware. >> We don't want to touch those existing peripherals' driver, such as >> ipmi-bt. >> So this driver applies the indirect-IO introduced in the previous >> patch >> after registering an indirect-IO node to the indirect-IO devices list >> which >> will be searched in the I/O accessors to retrieve the host-local I/O >> port. >> >> The driver config is set as a bool instead of a trisate. The reason >> here is that, by the very nature of the driver providing a logical >> PIO range, it does not make sense to have this driver as a loadable >> module. Another more specific reason is that the Huawei D03 board >> which includes hip06 SoC requires the LPC bus for UART console, so >> should be built in.
Hi Andy,
> > Few minor comments below. > >> +static inline int wait_lpc_idle(unsigned char *mbase, >> + unsigned int waitcnt) { >> + do { >> + u32 status; >> + >> + status = readl(mbase + LPC_REG_OP_STATUS); >> + if (status & LPC_REG_OP_STATUS_IDLE) >> + return (status & LPC_REG_OP_STATUS_FINISHED) >> ? 0 : -EIO; >> + ndelay(LPC_NSEC_PERWAIT); > >> + } while (waitcnt--); > > } while (--waitcnt);
Right, in reality it makes little difference, but we should honour the argument we are passed.
> >> + >> + return -ETIME; >> +} > >> + >> +/* > > If you would like to have a documentation you need to use proper syntax, > i.e. > > /** > > Check the rest of the series for it.
I don't think kerneldoc should include these functions - they are static and specific to this HW. I think the rest of the series is ok for kerneldoc vs non-kerneldoc comments. The logic_pio code does have kerneldoc comments. I will double check.
> >> + * hisi_lpc_target_in - trigger a series of LPC cycles for read >> operation >> + * @lpcdev: pointer to hisi lpc device >> + * @para: some parameters used to control the lpc I/O operations >> + * @addr: the lpc I/O target port address >> + * @buf: where the read back data is stored >> + * @opcnt: how many I/O operations required, i.e. data width >> + * >> + * Returns 0 on success, non-zero on fail. >> + */ > >> + do { >> + *buf++ = readb(lpcdev->membase + LPC_REG_RDATA); >> + } while (--opcnt); > > readsb() ? > >> + do { >> + writeb(*buf++, lpcdev->membase + LPC_REG_WDATA); >> + } while (--opcnt); > > writesb() ?
It should be ok to include these.
> >> +static inline unsigned long >> +hisi_lpc_pio_to_addr(struct hisi_lpc_dev *lpcdev, unsigned long pio) >> +{ >> + return pio - lpcdev->io_host->io_start + >> + lpcdev->io_host->hw_start; > > I would rather put on one line.
I will try.
> >> +} > >> + do { >> + if (hisi_lpc_target_out(lpcdev, &iopara, addr, buf, >> + dwidth)) > > Fancy indentation. Perhaps put to one line?
Will try
> >> + break; >> + buf += dwidth; >> + } while (--count); > > >> + int ret; >> + >> + lpcdev = devm_kzalloc(dev, sizeof(struct hisi_lpc_dev), >> GFP_KERNEL); > > sizeof(*lpcdev) ?
OK, will include
> >> + if (!lpcdev) >> + return -ENOMEM; > >> + dev_info(dev, "registered range[%pa - sz:%pa]\n", > > This is rather non-standard. We provide for resources the pattern like > "... [start-end]\n" > >> + &lpcdev->io_host->io_start, >> + &lpcdev->io_host->size);
In the HW structure we record the IO base and size, as the size of relevant to the bus address length. I could print in [start-end] format no problem.
>
Thanks, John
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