| Message ID | 1359395857-1235-4-git-send-email-arnd@arndb.de (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Mon, 28 Jan 2013 17:57:35 +0000, Arnd Bergmann <arnd@arndb.de> wrote: > 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 <arnd@arndb.de> > Cc: Grant Likely <grant.likely@secretlab.ca> > Cc: Jiri Slaby <jslaby@suse.cz> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Linus Walleij <linus.walleij@linaro.org> > Cc: spi-devel-general@lists.sourceforge.net > 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@vger.kernel.org Acked-by: Grant Likely <grant.likely@secretlab.ca> > --- > 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 >
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);
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 <arnd@arndb.de> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: spi-devel-general@lists.sourceforge.net 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@vger.kernel.org --- drivers/tty/serial/amba-pl011.c | 62 ++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 25 deletions(-)