With the new OF DMA binding, it is possible to completely avoid the need for platform_data for configuring a DMA channel. In cases where the platform has already been converted, calling dma_request_slave_channel should get all the necessary information from the device tree.
Like the patch that converts the dw_dma controller, this is completely untested and is looking for someone to try it out. Signed-off-by: Arnd Bergmann <[email protected]> Cc: Grant Likely <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Linus Walleij <[email protected]> Cc: [email protected] Cc: Viresh Kumar <[email protected]> Cc: Andy Shevchenko <[email protected]> Cc: Vinod Koul <[email protected]> Cc: [email protected] Cc: [email protected] --- drivers/tty/serial/amba-pl011.c | 62 ++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 25 deletions(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 3ea5408..c25b00e 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -245,7 +245,7 @@ static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg, } } -static void pl011_dma_probe_initcall(struct uart_amba_port *uap) +static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *uap) { /* DMA is the sole user of the platform data right now */ struct amba_pl011_data *plat = uap->port.dev->platform_data; @@ -259,20 +259,25 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap) struct dma_chan *chan; dma_cap_mask_t mask; - /* We need platform data */ - if (!plat || !plat->dma_filter) { - dev_info(uap->port.dev, "no DMA platform data\n"); - return; - } + chan = dma_request_slave_channel(dev, "tx"); - /* Try to acquire a generic DMA engine slave TX channel */ - dma_cap_zero(mask); - dma_cap_set(DMA_SLAVE, mask); - - chan = dma_request_channel(mask, plat->dma_filter, plat->dma_tx_param); if (!chan) { - dev_err(uap->port.dev, "no TX DMA channel!\n"); - return; + /* We need platform data */ + if (!plat || !plat->dma_filter) { + dev_info(uap->port.dev, "no DMA platform data\n"); + return; + } + + /* Try to acquire a generic DMA engine slave TX channel */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + chan = dma_request_channel(mask, plat->dma_filter, + plat->dma_tx_param); + if (!chan) { + dev_err(uap->port.dev, "no TX DMA channel!\n"); + return; + } } dmaengine_slave_config(chan, &tx_conf); @@ -282,7 +287,18 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap) dma_chan_name(uap->dmatx.chan)); /* Optionally make use of an RX channel as well */ - if (plat->dma_rx_param) { + chan = dma_request_slave_channel(dev, "rx"); + + if (!chan && plat->dma_rx_param) { + chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param); + + if (!chan) { + dev_err(uap->port.dev, "no RX DMA channel!\n"); + return; + } + } + + if (chan) { struct dma_slave_config rx_conf = { .src_addr = uap->port.mapbase + UART01x_DR, .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, @@ -291,12 +307,6 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap) .device_fc = false, }; - chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param); - if (!chan) { - dev_err(uap->port.dev, "no RX DMA channel!\n"); - return; - } - dmaengine_slave_config(chan, &rx_conf); uap->dmarx.chan = chan; @@ -315,6 +325,7 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap) struct dma_uap { struct list_head node; struct uart_amba_port *uap; + struct device *dev; }; static LIST_HEAD(pl011_dma_uarts); @@ -325,7 +336,7 @@ static int __init pl011_dma_initcall(void) list_for_each_safe(node, tmp, &pl011_dma_uarts) { struct dma_uap *dmau = list_entry(node, struct dma_uap, node); - pl011_dma_probe_initcall(dmau->uap); + pl011_dma_probe_initcall(dmau->dev, dmau->uap); list_del(node); kfree(dmau); } @@ -334,18 +345,19 @@ static int __init pl011_dma_initcall(void) device_initcall(pl011_dma_initcall); -static void pl011_dma_probe(struct uart_amba_port *uap) +static void pl011_dma_probe(struct device *dev, struct uart_amba_port *uap) { struct dma_uap *dmau = kzalloc(sizeof(struct dma_uap), GFP_KERNEL); if (dmau) { dmau->uap = uap; + dmau->dev = dev; list_add_tail(&dmau->node, &pl011_dma_uarts); } } #else -static void pl011_dma_probe(struct uart_amba_port *uap) +static void pl011_dma_probe(struct device *dev, struct uart_amba_port *uap) { - pl011_dma_probe_initcall(uap); + pl011_dma_probe_initcall(dev, uap); } #endif @@ -2020,7 +2032,7 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id) uap->port.ops = &amba_pl011_pops; uap->port.flags = UPF_BOOT_AUTOCONF; uap->port.line = i; - pl011_dma_probe(uap); + pl011_dma_probe(&dev->dev, uap); /* Ensure interrupts from this UART are masked and cleared */ writew(0, uap->port.membase + UART011_IMSC); -- 1.8.0 ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d _______________________________________________ spi-devel-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/spi-devel-general
