From a9ddb575d6d6c58c39e8c44a22b84445fedb0521 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Tue, 16 Oct 2012 09:49:17 +0530 Subject: [PATCH] dmaengine: dw_dmac: Enhance device tree support dw_dmac driver already supports device tree but it used to have its platform data passed the non-DT way. This patch does following changes: - pass platform data via DT, non-DT way still takes precedence if both are used. - create generic filter routine - Earlier slave information was made available by slave specific filter routines in chan->private field. Now, this information would be passed from within dmac DT node. Slave drivers would now be required to pass bus_id (a string) as parameter to this generic filter(), which would be compared against the slave data passed from DT, by the generic filter routine. - Update binding document Signed-off-by: Viresh Kumar Reviewed-by: Andy Shevchenko [Fixed __devinit usage] Signed-off-by: Vinod Koul --- .../devicetree/bindings/dma/snps-dma.txt | 44 ++++++ drivers/dma/dw_dmac.c | 134 ++++++++++++++++++ drivers/dma/dw_dmac_regs.h | 4 + include/linux/dw_dmac.h | 43 +++--- 4 files changed, 208 insertions(+), 17 deletions(-) diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt index c0d85dbcada5..5bb3dfb6f1d8 100644 --- a/Documentation/devicetree/bindings/dma/snps-dma.txt +++ b/Documentation/devicetree/bindings/dma/snps-dma.txt @@ -6,6 +6,26 @@ Required properties: - 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. +- 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. Example: @@ -14,4 +34,28 @@ Example: reg = <0xfc000000 0x1000>; interrupt-parent = <&vic1>; interrupts = <12>; + + nr_channels = <8>; + 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>; + }; + }; }; diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index 8f0b111af4de..27b8e1d1845e 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -1179,6 +1179,50 @@ 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 *dw = to_dw_dma(chan->device); + static struct dw_dma *last_dw; + static char *last_bus_id; + int i = -1; + + /* + * 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; + + 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; + + return true; + } + } + + last_dw = dw; + last_bus_id = param; + return false; +} +EXPORT_SYMBOL(dw_dma_generic_filter); + /* --------------------- Cyclic DMA API extensions -------------------- */ /** @@ -1462,6 +1506,91 @@ static void dw_dma_off(struct dw_dma *dw) dw->chan[i].initialized = false; } +#ifdef CONFIG_OF +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 dw_dma_platform_data *pdata; + struct dw_dma_slave *sd; + u32 tmp, arr[4]; + + if (!np) { + dev_err(&pdev->dev, "Missing DT data\n"); + return NULL; + } + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return NULL; + + if (of_property_read_u32(np, "nr_channels", &pdata->nr_channels)) + return NULL; + + if (of_property_read_bool(np, "is_private")) + pdata->is_private = true; + + if (!of_property_read_u32(np, "chan_allocation_order", &tmp)) + pdata->chan_allocation_order = (unsigned char)tmp; + + if (!of_property_read_u32(np, "chan_priority", &tmp)) + pdata->chan_priority = tmp; + + if (!of_property_read_u32(np, "block_size", &tmp)) + pdata->block_size = tmp; + + if (!of_property_read_u32(np, "nr_masters", &tmp)) { + if (tmp > 4) + return NULL; + + pdata->nr_masters = tmp; + } + + if (!of_property_read_u32_array(np, "data_width", arr, + pdata->nr_masters)) + 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 +static inline struct dw_dma_platform_data * +dw_dma_parse_dt(struct platform_device *pdev) +{ + return NULL; +} +#endif + static int dw_probe(struct platform_device *pdev) { struct dw_dma_platform_data *pdata; @@ -1478,6 +1607,9 @@ static int dw_probe(struct platform_device *pdev) int i; pdata = dev_get_platdata(&pdev->dev); + if (!pdata) + pdata = dw_dma_parse_dt(pdev); + if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) return -EINVAL; @@ -1512,6 +1644,8 @@ 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) { diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h index 88965597b7d0..88a069f66b89 100644 --- a/drivers/dma/dw_dmac_regs.h +++ b/drivers/dma/dw_dmac_regs.h @@ -239,6 +239,10 @@ 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 62a6190dee22..41766de66e33 100644 --- a/include/linux/dw_dmac.h +++ b/include/linux/dw_dmac.h @@ -14,6 +14,26 @@ #include +/** + * struct dw_dma_slave - Controller-specific information about a slave + * + * @dma_dev: required DMA master device. Depricated. + * @bus_id: name of this device channel, not just a device name since + * devices may have more than one channel e.g. "foo_tx" + * @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. + */ +struct dw_dma_slave { + struct device *dma_dev; + const char *bus_id; + u32 cfg_hi; + u32 cfg_lo; + u8 src_master; + u8 dst_master; +}; + /** * struct dw_dma_platform_data - Controller configuration parameters * @nr_channels: Number of channels supported by hardware (max 8) @@ -25,6 +45,8 @@ * @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) + * @sd: slave specific data. Used for configuring channels + * @sd_count: count of slave data structures passed. */ struct dw_dma_platform_data { unsigned int nr_channels; @@ -38,6 +60,9 @@ 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 */ @@ -52,23 +77,6 @@ enum dw_dma_msize { DW_DMA_MSIZE_256, }; -/** - * struct dw_dma_slave - Controller-specific information about a slave - * - * @dma_dev: required DMA master device - * @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. - */ -struct dw_dma_slave { - struct device *dma_dev; - u32 cfg_hi; - u32 cfg_lo; - u8 src_master; - u8 dst_master; -}; - /* Platform-configurable bits in CFG_HI */ #define DWC_CFGH_FCMODE (1 << 0) #define DWC_CFGH_FIFO_MODE (1 << 1) @@ -106,5 +114,6 @@ 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 */