Messages in this thread | | | Date | Mon, 5 Oct 2015 09:21:09 +0100 | From | Lee Jones <> | Subject | Re: [PATCH v2 3/3] mfd: add CSR SiRFSoC on-chip power management module driver |
| |
On Sun, 04 Oct 2015, Barry Song wrote: > 2015-09-29 16:55 GMT+08:00 Lee Jones <lee.jones@linaro.org>: > > On Tue, 29 Sep 2015, Barry Song wrote: > > > >> 2015-09-29 15:16 GMT+08:00 Lee Jones <lee.jones@linaro.org>: > >> > On Tue, 29 Sep 2015, Barry Song wrote: > >> >> >> >> +static int sirfsoc_pwrc_probe(struct platform_device *pdev) > >> >> >> >> +{ > >> >> >> >> + struct device_node *np = pdev->dev.of_node; > >> >> >> >> + const struct of_device_id *match; > >> >> >> >> + struct sirfsoc_pwrc_info *pwrcinfo; > >> >> >> >> + struct regmap_irq_chip *regmap_irq_chip; > >> >> >> >> + struct sirfsoc_pwrc_register *pwrc_reg; > >> >> >> >> + struct regmap *map; > >> >> >> >> + int ret; > >> >> >> >> + u32 base; > >> >> >> >> + > >> >> >> >> + if (of_property_read_u32(np, "reg", &base)) > >> >> >> >> + panic("unable to find base address of pwrc node in dtb\n"); > >> >> >> > > >> >> >> > It looks like this driver should depend on OF. > >> >> >> > > >> >> >> > Why are you obtaining the base address manually? Use: > >> >> >> > > >> >> >> > res = platform_get_resource(); > >> >> >> > devm_ioremap_resource(res); > >> >> >> > > >> >> >> > ... instead. > >> >> >> > >> >> >> this was explained as they are not in memory space, they are behind a > >> >> >> bus bridge. > >> >> > > >> >> > Use 'ranges' in the DT, then you can pull out the proper address > >> >> > without hand rolling your own method. > >> >> > >> >> it seems it is not a "ranges" thing, things behind rtciobrg is much > >> >> like things behind USB or sdio. we need to use a rtciobrg protocol to > >> >> do read/write. > >> >> they can not be randomly accessed by load/store, and can't be XIP. > >> >> they don't have any ranges in CPU memory space. > >> > > >> > So what's the point of 'base' then? I assumed this was the base of > >> > the IP registers which where memory mapped? > >> > >> just think we have a i2c device, and this i2c device has multi-functions. > >> each function has a base of its register offset. > >> actually, the base is the offset of 1st register. > > > > Does it every change, from device to device?
What I mean is ...
> yes. Lee. e.g: > > rtc-iobg@18840000 { > reg = <0x18840000 0x1000>; > > sysrtc@2000 {
Is sysrtc always @2000, or might it be @4000 on some devices?
> compatible = "sirf,prima2-sysrtc"; > reg = <0x2000 0x100>; > interrupts = <0 52 0>; > }; > pwrc@3000 {
Same for pwrc?
> compatible = "sirf,atlas7-pwrc"; > reg = <0x3000 0x100>; > interrupts = <0 32 0>; > }; > > } > > > -barry
-- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
| |