| Message ID | 1357751839-19680-2-git-send-email-p.zabel@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/09/2013 10:17 AM, Philipp Zabel wrote: > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > --- > .../devicetree/bindings/reset/fsl,imx-src.txt | 45 ++++++++++++++++++++ I proposed something very similar a while back; it may be useful to look at the previous discussion there: http://www.spinics.net/lists/arm-kernel/msg202451.html Unfortunately, I haven't had time to follow up on the proposal.
Hi Philipp, On Wed, Jan 09, 2013 at 06:17:15PM +0100, Philipp Zabel wrote: > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > --- > .../devicetree/bindings/reset/fsl,imx-src.txt | 45 ++++++++++++++++++++ > arch/arm/mach-imx/src.c | 41 ++++++++++++++++++ > include/linux/imx-src.h | 6 +++ > 3 files changed, 92 insertions(+) > create mode 100644 Documentation/devicetree/bindings/reset/fsl,imx-src.txt > create mode 100644 include/linux/imx-src.h I'm with Stephen that we should try to create a common API for this. Instead of ask device drivers to call IMX specific imx_src_reset(), we should have them call some type of common API with struct device as the argument. And the work of calling of_parse_phandle_with_args() should be done inside the API. It's pointless to ask every single client driver to do this same work. Shawn
Hi Stephen, Am Mittwoch, den 09.01.2013, 11:15 -0700 schrieb Stephen Warren: > On 01/09/2013 10:17 AM, Philipp Zabel wrote: > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > > --- > > .../devicetree/bindings/reset/fsl,imx-src.txt | 45 ++++++++++++++++++++ > > I proposed something very similar a while back; it may be useful to look > at the previous discussion there: > > http://www.spinics.net/lists/arm-kernel/msg202451.html Thanks, I had started playing around with some "reset subsystem" patches, but so far shied away from what feels like a whole lot of code for little effect. I came to the same conclusion that replacing gpio resets would probably be overkill, but I was only peripherally aware of the tegra reset controller. So a simple common struct and some oftree parsing code in drivers/reset that can replace both the proposed imx patch and what tegra_periph_reset_* do would be considered useful? > Unfortunately, I haven't had time to follow up on the proposal. regards Philipp
Am Donnerstag, den 10.01.2013, 14:56 +0800 schrieb Shawn Guo: > Hi Philipp, > > On Wed, Jan 09, 2013 at 06:17:15PM +0100, Philipp Zabel wrote: > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > > --- > > .../devicetree/bindings/reset/fsl,imx-src.txt | 45 ++++++++++++++++++++ > > arch/arm/mach-imx/src.c | 41 ++++++++++++++++++ > > include/linux/imx-src.h | 6 +++ > > 3 files changed, 92 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/reset/fsl,imx-src.txt > > create mode 100644 include/linux/imx-src.h > > I'm with Stephen that we should try to create a common API for this. > Instead of ask device drivers to call IMX specific imx_src_reset(), > we should have them call some type of common API with struct device > as the argument. Agreed. At least for devices with a single dedicated reset line this would be a much better API. regards Philipp
On 01/10/2013 06:51 AM, Philipp Zabel wrote: > Hi Stephen, > > Am Mittwoch, den 09.01.2013, 11:15 -0700 schrieb Stephen Warren: >> On 01/09/2013 10:17 AM, Philipp Zabel wrote: >>> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> >>> --- >>> .../devicetree/bindings/reset/fsl,imx-src.txt | 45 ++++++++++++++++++++ >> >> I proposed something very similar a while back; it may be useful to look >> at the previous discussion there: >> >> http://www.spinics.net/lists/arm-kernel/msg202451.html > > Thanks, I had started playing around with some "reset subsystem" > patches, but so far shied away from what feels like a whole lot of code > for little effect. I came to the same conclusion that replacing gpio > resets would probably be overkill, but I was only peripherally aware of > the tegra reset controller. > So a simple common struct and some oftree parsing code in drivers/reset > that can replace both the proposed imx patch and what > tegra_periph_reset_* do would be considered useful? Yes, I didn't really imagine the "reset subsystem" would do more than parsing the DT property that represented the reset and look up the registered reset controller and reset ID. Plus, provide some central function to pass the parsed reset ID to the reset controller driver. Of course, if it expanded to cover non-DT cases it might get more complex, but that can always be added later.
diff --git a/Documentation/devicetree/bindings/reset/fsl,imx-src.txt b/Documentation/devicetree/bindings/reset/fsl,imx-src.txt new file mode 100644 index 0000000..8f1e66a --- /dev/null +++ b/Documentation/devicetree/bindings/reset/fsl,imx-src.txt @@ -0,0 +1,45 @@ +Freescale i.MX System Reset Controller +====================================== + +Required properties: +- compatible: Should be "fsl,<chip>-src" +- reg: should be register base and length as documented in the + datasheet +- interrupts: Should contain SRC interrupt and CPU WDOG interrupt, + in this order. +- #reset-cells: 1, see below + +example: + +src: src@020d8000 { + compatible = "fsl,imx6q-src"; + reg = <0x020d8000 0x4000>; + interrupts = <0 91 0x04 0 96 0x04>; + #reset-cells = <1>; +}; + +Specifying reset lines connected to IP modules +============================================== + +The system reset controller can be used to reset the GPU, VPU, +IPU, and OpenVG IP modules on i.MX5 and i.MX6 ICs. Those device +nodes should specify the reset line on the SRC in their reset +property, containing a phandle to the SRC device node and a +RESET_INDEX specifying which module to reset. + +example: + + ipu0: ipu0 { + reset = <&src 2>; + }; + ipu1: ipu1 { + reset = <&src 4>; + }; + +The following RESET_INDEX values are valid for i.MX5: +GPU_RESET 0 +VPU_RESET 1 +IPU1_RESET 2 +OPEN_VG_RESET 3 +The following additional RESET_INDEX value is valid for i.MX6: +IPU2_RESET 4 diff --git a/arch/arm/mach-imx/src.c b/arch/arm/mach-imx/src.c index e15f155..10658b4 100644 --- a/arch/arm/mach-imx/src.c +++ b/arch/arm/mach-imx/src.c @@ -20,11 +20,52 @@ #define SRC_SCR 0x000 #define SRC_GPR1 0x020 #define BP_SRC_SCR_WARM_RESET_ENABLE 0 +#define BP_SRC_SCR_SW_GPU_RST 1 +#define BP_SRC_SCR_SW_VPU_RST 2 +#define BP_SRC_SCR_SW_IPU1_RST 3 +#define BP_SRC_SCR_SW_OPEN_VG_RST 4 +#define BP_SRC_SCR_SW_IPU2_RST 12 #define BP_SRC_SCR_CORE1_RST 14 #define BP_SRC_SCR_CORE1_ENABLE 22 static void __iomem *src_base; +static int sw_reset_bits[5] = { + BP_SRC_SCR_SW_GPU_RST, + BP_SRC_SCR_SW_VPU_RST, + BP_SRC_SCR_SW_IPU1_RST, + BP_SRC_SCR_SW_OPEN_VG_RST, + BP_SRC_SCR_SW_IPU2_RST +}; + +int imx_src_reset(int sw_reset_idx) +{ + unsigned long timeout; + int bit; + u32 val; + + if (!src_base) + return -ENODEV; + + if (sw_reset_idx >= ARRAY_SIZE(sw_reset_bits)) + return -EINVAL; + + bit = 1 << sw_reset_bits[sw_reset_idx]; + + val = readl_relaxed(src_base + SRC_SCR); + val |= bit; + writel_relaxed(val, src_base + SRC_SCR); + + timeout = jiffies + msecs_to_jiffies(1000); + while (readl(src_base + SRC_SCR) & bit) { + if (time_after(jiffies, timeout)) + return -ETIME; + cpu_relax(); + } + + return 0; +} + void imx_enable_cpu(int cpu, bool enable) { u32 mask, val; diff --git a/include/linux/imx-src.h b/include/linux/imx-src.h new file mode 100644 index 0000000..b93ed96 --- /dev/null +++ b/include/linux/imx-src.h @@ -0,0 +1,6 @@ +#ifndef __IMX_SRC_H__ +#define __IMX_SRC_H__ + +extern int imx_src_reset(int sw_reset_idx); + +#endif /* __IMX_SRC_H__ */
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> --- .../devicetree/bindings/reset/fsl,imx-src.txt | 45 ++++++++++++++++++++ arch/arm/mach-imx/src.c | 41 ++++++++++++++++++ include/linux/imx-src.h | 6 +++ 3 files changed, 92 insertions(+) create mode 100644 Documentation/devicetree/bindings/reset/fsl,imx-src.txt create mode 100644 include/linux/imx-src.h