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author | Viresh Kumar <viresh.kumar@linaro.org> | 2012-10-16 09:49:17 +0530 |
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committer | Vinod Koul <vinod.koul@intel.com> | 2013-01-07 22:04:14 -0800 |
commit | a9ddb575d6d6c58c39e8c44a22b84445fedb0521 (patch) | |
tree | 3c3b520bb61163d963c417c5355ac7c7cb5ad049 /drivers/dma/dw_dmac.c | |
parent | 177d2bf5c7d3ab41bfb4ce2597dde668225958dd (diff) | |
download | op-kernel-dev-a9ddb575d6d6c58c39e8c44a22b84445fedb0521.zip op-kernel-dev-a9ddb575d6d6c58c39e8c44a22b84445fedb0521.tar.gz |
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 <viresh.kumar@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Fixed __devinit usage]
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Diffstat (limited to 'drivers/dma/dw_dmac.c')
-rw-r--r-- | drivers/dma/dw_dmac.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index 8f0b111..27b8e1d 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) { |