| Message ID | 1360952512-971558-3-git-send-email-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 15 February 2013 23:51, Arnd Bergmann <arnd@arndb.de> wrote: > diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt > +- #dma-cells: must be <3> > +DMA clients connected to the Designware DMA controller must use the format > +described in the dma.txt file, using a five-cell specifier for each channel. s/five/four ? > +The four cells in order are: > + > +1. A phandle pointing to the DMA controller > +2. The DMA request line number > +3. Source master for transfers on allocated channel > +4. Destination master for transfers on allocated channel > diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c > +static bool dw_dma_generic_filter(struct dma_chan *chan, void *param) > { > + dws->cfg_hi = 0xffffffff; > + dws->cfg_lo = 0xffffffff; s/0xffffffff/-1 ? > + dws->src_master = fargs->src; > + dws->dst_master = fargs->dst; > + dwc->req = fargs->req; > > - return true; > - } > - } > + chan->private = dws; > + > + return true; > +} > + > +static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec, > + struct of_dma *ofdma) > +{ > + struct dw_dma *dw = ofdma->of_dma_data; > + struct dw_dma_filter_args fargs = { > + .dw = dw, > + }; > + dma_cap_mask_t cap; > + > + if (dma_spec->args_count != 3) > + return NULL; > + > + fargs.req = be32_to_cpup(dma_spec->args+0); > + fargs.src = be32_to_cpup(dma_spec->args+1); > + fargs.dst = be32_to_cpup(dma_spec->args+2); > + > + if (WARN_ON(fargs.req >= 16 || fargs.src >= 2 || fargs.dst >= 2)) > + return NULL; > > - last_dw = dw; > - last_bus_id = param; > - return false; > + dma_cap_zero(cap); > + dma_cap_set(DMA_SLAVE, cap); > + > + /* TODO: there should be a simpler way to do this */ > + return dma_request_channel(cap, dw_dma_generic_filter, &dma_spec->args[0]); > } > -EXPORT_SYMBOL(dw_dma_generic_filter); > > /* --------------------- Cyclic DMA API extensions -------------------- */ > > @@ -1510,9 +1529,8 @@ static void dw_dma_off(struct dw_dma *dw) > static struct dw_dma_platform_data * > dw_dma_parse_dt(struct platform_device *pdev) > { > - struct device_node *sn, *cn, *np = pdev->dev.of_node; > + struct device_node *np = pdev->dev.of_node; > struct dw_dma_platform_data *pdata; > - struct dw_dma_slave *sd; > u32 tmp, arr[4]; > > if (!np) { > @@ -1524,7 +1542,7 @@ dw_dma_parse_dt(struct platform_device *pdev) > if (!pdata) > return NULL; > > - if (of_property_read_u32(np, "nr_channels", &pdata->nr_channels)) > + if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels)) > return NULL;
On Saturday 16 February 2013, Viresh Kumar wrote: > On 15 February 2013 23:51, Arnd Bergmann <arnd@arndb.de> wrote: > > diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt > > +- #dma-cells: must be <3> > > > +DMA clients connected to the Designware DMA controller must use the format > > +described in the dma.txt file, using a five-cell specifier for each channel. > > s/five/four ? Right. I thought I had fixed up all instances. > > +static bool dw_dma_generic_filter(struct dma_chan *chan, void *param) > > { > > > + dws->cfg_hi = 0xffffffff; > > + dws->cfg_lo = 0xffffffff; > > s/0xffffffff/-1 ? It's an 'unsigned int'. While -1 would work here, I always find it a little odd to rely on that feature of the C language. Thannks for the review. Arnd
On Sat, Feb 16, 2013 at 10:07:39AM +0000, Arnd Bergmann wrote: > On Saturday 16 February 2013, Viresh Kumar wrote: > > On 15 February 2013 23:51, Arnd Bergmann <arnd@arndb.de> wrote: > > > +static bool dw_dma_generic_filter(struct dma_chan *chan, void *param) > > > { > > > > > + dws->cfg_hi = 0xffffffff; > > > + dws->cfg_lo = 0xffffffff; > > > > s/0xffffffff/-1 ? > > It's an 'unsigned int'. While -1 would work here, I always find it a little > odd to rely on that feature of the C language. However, relying on an 'int' being 32-bits is also rather odd, and probably much more dubious too. If you want to set all bits in an int, the portable way to do that is ~0.
On Fri, Feb 15, 2013 at 8:21 PM, Arnd Bergmann <arnd@arndb.de> wrote: > The original device tree binding for this driver, from Viresh Kumar > unfortunately conflicted with the generic DMA binding, and did not allow > to completely seperate slave device configuration from the controller. > > This is an attempt to replace it with an implementation of the generic > binding, but it is currently completely untested, because I do not have > any hardware with this particular controller. > > The patch applies on top of linux-next, which contains both the base > support for the generic DMA binding, as well as the earlier attempt from > Viresh. Both of these are currently not merged upstream however. > > There are a couple of TODO items that are left remaining and are open > for ideas from other people. > --- a/drivers/dma/dw_dmac.c > +++ b/drivers/dma/dw_dmac.c > @@ -168,7 +169,13 @@ static void dwc_initialize(struct dw_dma_chan *dwc) > if (dwc->initialized == true) > return; > > - if (dws) { > + if (dws && dws->cfg_hi == 0xffffffff && dws->cfg_lo == 0xffffffff) { > + /* autoconfigure based on request line from DT */ > + if (dwc->dma_sconfig.direction == DMA_MEM_TO_DEV) > + cfghi = DWC_CFGH_DST_PER(dwc->req); > + else if (dwc->dma_sconfig.direction == DMA_DEV_TO_MEM) > + cfghi = DWC_CFGH_SRC_PER(dwc->req); Please, use dwc->direction instead of field in the slave_config. If I remember correctly it's marked like obsoleted/deprecated. > @@ -1179,49 +1186,61 @@ static void dwc_free_chan_resources(struct dma_chan *chan) > dev_vdbg(chan2dev(chan), "%s: done\n", __func__); > } > > -bool dw_dma_generic_filter(struct dma_chan *chan, void *param) > +struct dw_dma_filter_args { > + struct dw_dma *dw; > + u32 req; Why this is u32 and not unsigned int? > + u32 src; > + u32 dst; And this could be also just unsigned int. > +static bool dw_dma_generic_filter(struct dma_chan *chan, void *param) > { > + dws->cfg_hi = 0xffffffff; > + dws->cfg_lo = 0xffffffff; Agree with Russell about ~0. > +static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec, > + struct of_dma *ofdma) > +{ > + struct dw_dma *dw = ofdma->of_dma_data; > + struct dw_dma_filter_args fargs = { > + .dw = dw, > + }; > + dma_cap_mask_t cap; > + > + if (dma_spec->args_count != 3) > + return NULL; > + > + fargs.req = be32_to_cpup(dma_spec->args+0); > + fargs.src = be32_to_cpup(dma_spec->args+1); > + fargs.dst = be32_to_cpup(dma_spec->args+2); You could cast them to usual C types like unsigned int. I see u32 in rare cases in the driver like for reading/writting from/to hw and when API contains it. Here I doubt we have to leave them as u32. > + > + if (WARN_ON(fargs.req >= 16 || fargs.src >= 2 || fargs.dst >= 2)) > + return NULL; 16 here is a magic number for me. I would like to see something like #define DW_MAX_REQUEST_LINES 16 in the dw_dmac_regs.h. Besides of that, what 2 does come from? > @@ -1765,6 +1751,10 @@ static int dw_probe(struct platform_device *pdev) > > dma_async_device_register(&dw->dma); > > + err = of_dma_controller_register(pdev->dev.of_node, dw_dma_xlate, dw); > + if (err) > + dev_err(&pdev->dev, "could not register of_dma_controller\n"); It's not an error, dev_dbg. Consider case when !CONFIG_OF. > --- a/drivers/dma/dw_dmac_regs.h > +++ b/drivers/dma/dw_dmac_regs.h > @@ -213,6 +213,10 @@ struct dw_dma_chan { > /* configuration passed via DMA_SLAVE_CONFIG */ > struct dma_slave_config dma_sconfig; > > + /* slave configuration from DT */ > + unsigned int req; Could you use here full name like "request_line"? And I think the better place for it in subsection "hardware configuration" (consider non-DT cases of use). > /* backlink to dw_dma */ > struct dw_dma *dw; > }; We should not have this in linux-next. Are you sure you rebased it on top of recent one?
On Saturday 16 February 2013, Russell King - ARM Linux wrote: > On Sat, Feb 16, 2013 at 10:07:39AM +0000, Arnd Bergmann wrote: > > On Saturday 16 February 2013, Viresh Kumar wrote: > > > On 15 February 2013 23:51, Arnd Bergmann <arnd@arndb.de> wrote: > > > > +static bool dw_dma_generic_filter(struct dma_chan *chan, void *param) > > > > { > > > > > > > + dws->cfg_hi = 0xffffffff; > > > > + dws->cfg_lo = 0xffffffff; > > > > > > s/0xffffffff/-1 ? > > > > It's an 'unsigned int'. While -1 would work here, I always find it a little > > odd to rely on that feature of the C language. > > However, relying on an 'int' being 32-bits is also rather odd, and > probably much more dubious too. If you want to set all bits in an > int, the portable way to do that is ~0. Right, I can do that, too. All I really need here though is to make sure I use the same value in this place and when comparing it in dwc_initialize, and it needs to be something that cannot be a valid register setting. Thanks, Arnd
On Saturday 16 February 2013, Andy Shevchenko wrote: > On Fri, Feb 15, 2013 at 8:21 PM, Arnd Bergmann <arnd@arndb.de> wrote: > > > @@ -168,7 +169,13 @@ static void dwc_initialize(struct dw_dma_chan *dwc) > > if (dwc->initialized == true) > > return; > > > > - if (dws) { > > + if (dws && dws->cfg_hi == 0xffffffff && dws->cfg_lo == 0xffffffff) { > > + /* autoconfigure based on request line from DT */ > > + if (dwc->dma_sconfig.direction == DMA_MEM_TO_DEV) > > + cfghi = DWC_CFGH_DST_PER(dwc->req); > > + else if (dwc->dma_sconfig.direction == DMA_DEV_TO_MEM) > > + cfghi = DWC_CFGH_SRC_PER(dwc->req); > > Please, use dwc->direction instead of field in the slave_config. If I > remember correctly it's marked like obsoleted/deprecated. Ok, that's easy to change. I was copying from the code you added a few lines below, but was using an older version than the one where you had made the change to use dwc->direction. > > @@ -1179,49 +1186,61 @@ static void dwc_free_chan_resources(struct dma_chan *chan) > > dev_vdbg(chan2dev(chan), "%s: done\n", __func__); > > } > > > > -bool dw_dma_generic_filter(struct dma_chan *chan, void *param) > > +struct dw_dma_filter_args { > > + struct dw_dma *dw; > > + u32 req; > > Why this is u32 and not unsigned int? > > > + u32 src; > > + u32 dst; > > And this could be also just unsigned int. I was using u32 since I copied the values from a 32 bit DT property value. I'll change it to unsigned int. > > +static bool dw_dma_generic_filter(struct dma_chan *chan, void *param) > > { > > > + dws->cfg_hi = 0xffffffff; > > + dws->cfg_lo = 0xffffffff; > > Agree with Russell about ~0. ok. > > +static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec, > > + struct of_dma *ofdma) > > +{ > > + struct dw_dma *dw = ofdma->of_dma_data; > > + struct dw_dma_filter_args fargs = { > > + .dw = dw, > > + }; > > + dma_cap_mask_t cap; > > + > > + if (dma_spec->args_count != 3) > > + return NULL; > > + > > + fargs.req = be32_to_cpup(dma_spec->args+0); > > + fargs.src = be32_to_cpup(dma_spec->args+1); > > + fargs.dst = be32_to_cpup(dma_spec->args+2); > > You could cast them to usual C types like unsigned int. I see u32 in > rare cases in the driver like for reading/writting from/to hw and when > API contains it. Here I doubt we have to leave them as u32. Right. > > + if (WARN_ON(fargs.req >= 16 || fargs.src >= 2 || fargs.dst >= 2)) > > + return NULL; > > 16 here is a magic number for me. I would like to see something like > #define DW_MAX_REQUEST_LINES 16 in the dw_dmac_regs.h. Ok. > Besides of that, what 2 does come from? I thought that Viresh had commented that there could only be two masters. It's probably best to compare against dw->nr_masters here. > > @@ -1765,6 +1751,10 @@ static int dw_probe(struct platform_device *pdev) > > > > dma_async_device_register(&dw->dma); > > > > + err = of_dma_controller_register(pdev->dev.of_node, dw_dma_xlate, dw); > > + if (err) > > + dev_err(&pdev->dev, "could not register of_dma_controller\n"); > > It's not an error, dev_dbg. Consider case when !CONFIG_OF. Ah right. I expected of_dma_controller_register to return 0 in that case, but it returns -ENODEV. How about I change this to this? if (pdev->dev.of_node) err = of_dma_controller_register(pdev->dev.of_node, dw_dma_xlate, dw); if (err && err != -ENODEV) dev_err(&pdev->dev, "could not register of_dma_controller\n"); That would warn only when we have a dw_dmac device that was registered from device tree but does not follow the binding or gets an -ENOMEM. > > --- a/drivers/dma/dw_dmac_regs.h > > +++ b/drivers/dma/dw_dmac_regs.h > > @@ -213,6 +213,10 @@ struct dw_dma_chan { > > /* configuration passed via DMA_SLAVE_CONFIG */ > > struct dma_slave_config dma_sconfig; > > > > + /* slave configuration from DT */ > > + unsigned int req; > > Could you use here full name like "request_line"? And I think the > better place for it in subsection "hardware configuration" (consider > non-DT cases of use). Ok > > > /* backlink to dw_dma */ > > struct dw_dma *dw; > > }; > > We should not have this in linux-next. Are you sure you rebased it on > top of recent one? I was basing on the earliest commit that had Viresh's changes in it. I'll rebase on top of Vinod's branch now. Thanks for your review! Arnd
On Sat, Feb 16, 2013 at 4:00 PM, Arnd Bergmann <arnd@arndb.de> wrote: > On Saturday 16 February 2013, Andy Shevchenko wrote: >> On Fri, Feb 15, 2013 at 8:21 PM, Arnd Bergmann <arnd@arndb.de> wrote: >> > + if (WARN_ON(fargs.req >= 16 || fargs.src >= 2 || fargs.dst >= 2)) >> > + return NULL; >> >> 16 here is a magic number for me. I would like to see something like >> #define DW_MAX_REQUEST_LINES 16 in the dw_dmac_regs.h. > > Ok. > >> Besides of that, what 2 does come from? > > I thought that Viresh had commented that there could only be two masters. > It's probably best to compare against dw->nr_masters here. Right. >> > @@ -1765,6 +1751,10 @@ static int dw_probe(struct platform_device *pdev) >> > >> > dma_async_device_register(&dw->dma); >> > >> > + err = of_dma_controller_register(pdev->dev.of_node, dw_dma_xlate, dw); >> > + if (err) >> > + dev_err(&pdev->dev, "could not register of_dma_controller\n"); >> >> It's not an error, dev_dbg. Consider case when !CONFIG_OF. > > Ah right. I expected of_dma_controller_register to return 0 in that case, but > it returns -ENODEV. How about I change this to this? > > if (pdev->dev.of_node) > err = of_dma_controller_register(pdev->dev.of_node, dw_dma_xlate, dw); > if (err && err != -ENODEV) > dev_err(&pdev->dev, "could not register of_dma_controller\n"); > > That would warn only when we have a dw_dmac device that was registered from > device tree but does not follow the binding or gets an -ENOMEM. I'm okay with it. > Thanks for your review! Thanks for the patch!
diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt index 5bb3dfb..68783d3 100644 --- a/Documentation/devicetree/bindings/dma/snps-dma.txt +++ b/Documentation/devicetree/bindings/dma/snps-dma.txt @@ -3,59 +3,61 @@ Required properties: - compatible: "snps,dma-spear1340" - reg: Address range of the DMAC registers -- interrupt-parent: Should be the phandle for the interrupt controller - that services interrupts for this device - interrupt: Should contain the DMAC interrupt number -- nr_channels: Number of channels supported by hardware -- is_private: The device channels should be marked as private and not for by the - general purpose DMA channel allocator. False if not passed. +- dma-channels: Number of channels supported by hardware +- dma-requests: Number of DMA request lines supported, up to 16 +- dma-masters: Number of AHB masters supported by the controller +- #dma-cells: must be <3> - chan_allocation_order: order of allocation of channel, 0 (default): ascending, 1: descending - chan_priority: priority of channels. 0 (default): increase from chan 0->n, 1: increase from chan n->0 - block_size: Maximum block size supported by the controller -- nr_masters: Number of AHB masters supported by the controller - data_width: Maximum data width supported by hardware per AHB master (0 - 8bits, 1 - 16bits, ..., 5 - 256bits) -- slave_info: - - bus_id: name of this device channel, not just a device name since - devices may have more than one channel e.g. "foo_tx". For using the - dw_generic_filter(), slave drivers must pass exactly this string as - param to filter function. - - cfg_hi: Platform-specific initializer for the CFG_HI register - - cfg_lo: Platform-specific initializer for the CFG_LO register - - src_master: src master for transfers on allocated channel. - - dst_master: dest master for transfers on allocated channel. + + +Optional properties: +- interrupt-parent: Should be the phandle for the interrupt controller + that services interrupts for this device +- is_private: The device channels should be marked as private and not for by the + general purpose DMA channel allocator. False if not passed. Example: - dma@fc000000 { + dmahost: dma@fc000000 { compatible = "snps,dma-spear1340"; reg = <0xfc000000 0x1000>; interrupt-parent = <&vic1>; interrupts = <12>; - nr_channels = <8>; + dma-channels = <8>; + dma-requests = <16>; + dma-masters = <2>; + #dma-cells = <3>; chan_allocation_order = <1>; chan_priority = <1>; block_size = <0xfff>; - nr_masters = <2>; data_width = <3 3 0 0>; + }; - slave_info { - uart0-tx { - bus_id = "uart0-tx"; - cfg_hi = <0x4000>; /* 0x8 << 11 */ - cfg_lo = <0>; - src_master = <0>; - dst_master = <1>; - }; - spi0-tx { - bus_id = "spi0-tx"; - cfg_hi = <0x2000>; /* 0x4 << 11 */ - cfg_lo = <0>; - src_master = <0>; - dst_master = <0>; - }; - }; +DMA clients connected to the Designware DMA controller must use the format +described in the dma.txt file, using a five-cell specifier for each channel. +The four cells in order are: + +1. A phandle pointing to the DMA controller +2. The DMA request line number +3. Source master for transfers on allocated channel +4. Destination master for transfers on allocated channel + +Example: + + serial@e0000000 { + compatible = "arm,pl011", "arm,primecell"; + reg = <0xe0000000 0x1000>; + interrupts = <0 35 0x4>; + status = "disabled"; + dmas = <&dmahost 12 0 1>, + <&dmahost 13 0 1 0>; + dma-names = "rx", "rx"; }; diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index 27b8e1d..208646c 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -18,6 +18,7 @@ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/of.h> +#include <linux/of_dma.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/platform_device.h> @@ -168,7 +169,13 @@ static void dwc_initialize(struct dw_dma_chan *dwc) if (dwc->initialized == true) return; - if (dws) { + if (dws && dws->cfg_hi == 0xffffffff && dws->cfg_lo == 0xffffffff) { + /* autoconfigure based on request line from DT */ + if (dwc->dma_sconfig.direction == DMA_MEM_TO_DEV) + cfghi = DWC_CFGH_DST_PER(dwc->req); + else if (dwc->dma_sconfig.direction == DMA_DEV_TO_MEM) + cfghi = DWC_CFGH_SRC_PER(dwc->req); + } else if (dws) { /* * We need controller-specific data to set up slave * transfers. @@ -1179,49 +1186,61 @@ static void dwc_free_chan_resources(struct dma_chan *chan) dev_vdbg(chan2dev(chan), "%s: done\n", __func__); } -bool dw_dma_generic_filter(struct dma_chan *chan, void *param) +struct dw_dma_filter_args { + struct dw_dma *dw; + u32 req; + u32 src; + u32 dst; +}; + +static bool dw_dma_generic_filter(struct dma_chan *chan, void *param) { + struct dw_dma_chan *dwc = to_dw_dma_chan(chan); struct dw_dma *dw = to_dw_dma(chan->device); - static struct dw_dma *last_dw; - static char *last_bus_id; - int i = -1; + struct dw_dma_filter_args *fargs = param; + struct dw_dma_slave *dws = &dwc->slave; - /* - * dmaengine framework calls this routine for all channels of all dma - * controller, until true is returned. If 'param' bus_id is not - * registered with a dma controller (dw), then there is no need of - * running below function for all channels of dw. - * - * This block of code does this by saving the parameters of last - * failure. If dw and param are same, i.e. trying on same dw with - * different channel, return false. - */ - if ((last_dw == dw) && (last_bus_id == param)) - return false; - /* - * Return true: - * - If dw_dma's platform data is not filled with slave info, then all - * dma controllers are fine for transfer. - * - Or if param is NULL - */ - if (!dw->sd || !param) - return true; + /* both the driver and the device must match */ + if (chan->device != &fargs->dw->dma) + return false; - while (++i < dw->sd_count) { - if (!strcmp(dw->sd[i].bus_id, param)) { - chan->private = &dw->sd[i]; - last_dw = NULL; - last_bus_id = NULL; + dws->dma_dev = dw->dma.dev; + dws->cfg_hi = 0xffffffff; + dws->cfg_lo = 0xffffffff; + dws->src_master = fargs->src; + dws->dst_master = fargs->dst; + dwc->req = fargs->req; - return true; - } - } + chan->private = dws; + + return true; +} + +static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct dw_dma *dw = ofdma->of_dma_data; + struct dw_dma_filter_args fargs = { + .dw = dw, + }; + dma_cap_mask_t cap; + + if (dma_spec->args_count != 3) + return NULL; + + fargs.req = be32_to_cpup(dma_spec->args+0); + fargs.src = be32_to_cpup(dma_spec->args+1); + fargs.dst = be32_to_cpup(dma_spec->args+2); + + if (WARN_ON(fargs.req >= 16 || fargs.src >= 2 || fargs.dst >= 2)) + return NULL; - last_dw = dw; - last_bus_id = param; - return false; + dma_cap_zero(cap); + dma_cap_set(DMA_SLAVE, cap); + + /* TODO: there should be a simpler way to do this */ + return dma_request_channel(cap, dw_dma_generic_filter, &dma_spec->args[0]); } -EXPORT_SYMBOL(dw_dma_generic_filter); /* --------------------- Cyclic DMA API extensions -------------------- */ @@ -1510,9 +1529,8 @@ static void dw_dma_off(struct dw_dma *dw) static struct dw_dma_platform_data * dw_dma_parse_dt(struct platform_device *pdev) { - struct device_node *sn, *cn, *np = pdev->dev.of_node; + struct device_node *np = pdev->dev.of_node; struct dw_dma_platform_data *pdata; - struct dw_dma_slave *sd; u32 tmp, arr[4]; if (!np) { @@ -1524,7 +1542,7 @@ dw_dma_parse_dt(struct platform_device *pdev) if (!pdata) return NULL; - if (of_property_read_u32(np, "nr_channels", &pdata->nr_channels)) + if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels)) return NULL; if (of_property_read_bool(np, "is_private")) @@ -1539,7 +1557,7 @@ dw_dma_parse_dt(struct platform_device *pdev) if (!of_property_read_u32(np, "block_size", &tmp)) pdata->block_size = tmp; - if (!of_property_read_u32(np, "nr_masters", &tmp)) { + if (!of_property_read_u32(np, "dma-masters", &tmp)) { if (tmp > 4) return NULL; @@ -1551,36 +1569,6 @@ dw_dma_parse_dt(struct platform_device *pdev) for (tmp = 0; tmp < pdata->nr_masters; tmp++) pdata->data_width[tmp] = arr[tmp]; - /* parse slave data */ - sn = of_find_node_by_name(np, "slave_info"); - if (!sn) - return pdata; - - /* calculate number of slaves */ - tmp = of_get_child_count(sn); - if (!tmp) - return NULL; - - sd = devm_kzalloc(&pdev->dev, sizeof(*sd) * tmp, GFP_KERNEL); - if (!sd) - return NULL; - - pdata->sd = sd; - pdata->sd_count = tmp; - - for_each_child_of_node(sn, cn) { - sd->dma_dev = &pdev->dev; - of_property_read_string(cn, "bus_id", &sd->bus_id); - of_property_read_u32(cn, "cfg_hi", &sd->cfg_hi); - of_property_read_u32(cn, "cfg_lo", &sd->cfg_lo); - if (!of_property_read_u32(cn, "src_master", &tmp)) - sd->src_master = tmp; - - if (!of_property_read_u32(cn, "dst_master", &tmp)) - sd->dst_master = tmp; - sd++; - } - return pdata; } #else @@ -1644,8 +1632,6 @@ static int dw_probe(struct platform_device *pdev) clk_prepare_enable(dw->clk); dw->regs = regs; - dw->sd = pdata->sd; - dw->sd_count = pdata->sd_count; /* get hardware configuration parameters */ if (autocfg) { @@ -1765,6 +1751,10 @@ static int dw_probe(struct platform_device *pdev) dma_async_device_register(&dw->dma); + err = of_dma_controller_register(pdev->dev.of_node, dw_dma_xlate, dw); + if (err) + dev_err(&pdev->dev, "could not register of_dma_controller\n"); + return 0; } @@ -1773,6 +1763,7 @@ static int __devexit dw_remove(struct platform_device *pdev) struct dw_dma *dw = platform_get_drvdata(pdev); struct dw_dma_chan *dwc, *_dwc; + of_dma_controller_free(pdev->dev.of_node); dw_dma_off(dw); dma_async_device_unregister(&dw->dma); diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h index 88a069f..1d17793 100644 --- a/drivers/dma/dw_dmac_regs.h +++ b/drivers/dma/dw_dmac_regs.h @@ -213,6 +213,10 @@ struct dw_dma_chan { /* configuration passed via DMA_SLAVE_CONFIG */ struct dma_slave_config dma_sconfig; + /* slave configuration from DT */ + unsigned int req; + struct dw_dma_slave slave; + /* backlink to dw_dma */ struct dw_dma *dw; }; @@ -239,10 +243,6 @@ struct dw_dma { struct tasklet_struct tasklet; struct clk *clk; - /* slave information */ - struct dw_dma_slave *sd; - unsigned int sd_count; - u8 all_chan_mask; /* hardware configuration */ diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h index 41766de..481ab23 100644 --- a/include/linux/dw_dmac.h +++ b/include/linux/dw_dmac.h @@ -27,7 +27,6 @@ */ struct dw_dma_slave { struct device *dma_dev; - const char *bus_id; u32 cfg_hi; u32 cfg_lo; u8 src_master; @@ -60,9 +59,6 @@ struct dw_dma_platform_data { unsigned short block_size; unsigned char nr_masters; unsigned char data_width[4]; - - struct dw_dma_slave *sd; - unsigned int sd_count; }; /* bursts size */ @@ -114,6 +110,5 @@ void dw_dma_cyclic_stop(struct dma_chan *chan); dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan); dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan); -bool dw_dma_generic_filter(struct dma_chan *chan, void *param); #endif /* DW_DMAC_H */
The original device tree binding for this driver, from Viresh Kumar unfortunately conflicted with the generic DMA binding, and did not allow to completely seperate slave device configuration from the controller. This is an attempt to replace it with an implementation of the generic binding, but it is currently completely untested, because I do not have any hardware with this particular controller. The patch applies on top of linux-next, which contains both the base support for the generic DMA binding, as well as the earlier attempt from Viresh. Both of these are currently not merged upstream however. There are a couple of TODO items that are left remaining and are open for ideas from other people. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Vinod Koul <vinod.koul@linux.intel.com> Cc: devicetree-discuss@lists.ozlabs.org Cc: linux-arm-kernel@lists.infradead.org --- Documentation/devicetree/bindings/dma/snps-dma.txt | 70 ++++++----- drivers/dma/dw_dmac.c | 137 ++++++++++----------- drivers/dma/dw_dmac_regs.h | 8 +- include/linux/dw_dmac.h | 5 - 4 files changed, 104 insertions(+), 116 deletions(-)