From ff4411296e99db2c0896580d8b47348abf3ad703 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 18 Sep 2015 13:08:33 +0200 Subject: [PATCH] serial: sh-sci: Add DT support to DMA setup Add support for obtaining DMA channel information from the device tree. This requires switching from the legacy sh_dmae_slave structures with hardcoded channel numbers and the corresponding filter function to: 1. dma_request_slave_channel_compat(), - On legacy platforms, dma_request_slave_channel_compat() uses the passed DMA channel numbers that originate from platform device data, - On DT-based platforms, dma_request_slave_channel_compat() will retrieve the information from DT. 2. and the generic dmaengine_slave_config() configuration method, which requires filling in DMA register ports and slave bus widths. Signed-off-by: Geert Uytterhoeven Acked-by: Laurent Pinchart Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 78 ++++++++++++++++++++++--------------- 1 file changed, 47 insertions(+), 31 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index b1d1ce1986e6..960e50a97558 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -112,8 +112,6 @@ struct sci_port { struct scatterlist sg_rx[2]; void *rx_buf[2]; size_t buf_len_rx; - struct sh_dmae_slave param_tx; - struct sh_dmae_slave param_rx; struct work_struct work_tx; struct timer_list rx_timer; unsigned int rx_timeout; @@ -1263,17 +1261,6 @@ static void work_fn_tx(struct work_struct *work) dma_async_issue_pending(chan); } -static bool filter(struct dma_chan *chan, void *slave) -{ - struct sh_dmae_slave *param = slave; - - dev_dbg(chan->device->dev, "%s: slave ID %d\n", - __func__, param->shdma_slave.slave_id); - - chan->private = ¶m->shdma_slave; - return true; -} - static void rx_timer_fn(unsigned long arg) { struct sci_port *s = (struct sci_port *)arg; @@ -1347,28 +1334,62 @@ static void rx_timer_fn(unsigned long arg) spin_unlock_irqrestore(&port->lock, flags); } +static struct dma_chan *sci_request_dma_chan(struct uart_port *port, + enum dma_transfer_direction dir, + unsigned int id) +{ + dma_cap_mask_t mask; + struct dma_chan *chan; + struct dma_slave_config cfg; + int ret; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + chan = dma_request_slave_channel_compat(mask, shdma_chan_filter, + (void *)(unsigned long)id, port->dev, + dir == DMA_MEM_TO_DEV ? "tx" : "rx"); + if (!chan) { + dev_warn(port->dev, + "dma_request_slave_channel_compat failed\n"); + return NULL; + } + + memset(&cfg, 0, sizeof(cfg)); + cfg.direction = dir; + if (dir == DMA_MEM_TO_DEV) { + cfg.dst_addr = port->mapbase + + (sci_getreg(port, SCxTDR)->offset << port->regshift); + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } else { + cfg.src_addr = port->mapbase + + (sci_getreg(port, SCxRDR)->offset << port->regshift); + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } + + ret = dmaengine_slave_config(chan, &cfg); + if (ret) { + dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret); + dma_release_channel(chan); + return NULL; + } + + return chan; +} + static void sci_request_dma(struct uart_port *port) { struct sci_port *s = to_sci_port(port); - struct sh_dmae_slave *param; struct dma_chan *chan; - dma_cap_mask_t mask; dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); - if (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0) + if (!port->dev->of_node && + (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0)) return; - dma_cap_zero(mask); - dma_cap_set(DMA_SLAVE, mask); - - param = &s->param_tx; - - /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */ - param->shdma_slave.slave_id = s->cfg->dma_slave_tx; - s->cookie_tx = -EINVAL; - chan = dma_request_channel(mask, filter, param); + chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV, s->cfg->dma_slave_tx); dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan); if (chan) { s->chan_tx = chan; @@ -1390,12 +1411,7 @@ static void sci_request_dma(struct uart_port *port) INIT_WORK(&s->work_tx, work_fn_tx); } - param = &s->param_rx; - - /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */ - param->shdma_slave.slave_id = s->cfg->dma_slave_rx; - - chan = dma_request_channel(mask, filter, param); + chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM, s->cfg->dma_slave_rx); dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan); if (chan) { unsigned int i; -- 2.39.5