[PATCH 45/76] serial: mfd: add a module parameter for setting each port's working mode
From: Greg Kroah-Hartman <gregkh@suse.de>
Date: 2011-03-16 21:14:27
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
From: Feng Tang <redacted> The three identical uart ports can work either in DMA or PIO mode. Adding such a module parameter "hsu_dma_enable" will enable user to chose working modes for each port. If the mfd driver is built in kernel, adding a "mfd.hsu_dma_enable=x" in kernel command line has the same effect. Signed-off-by: Feng Tang <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- drivers/tty/serial/mfd.c | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/tty/serial/mfd.c b/drivers/tty/serial/mfd.c
index 53ff6af..c111f36 100644
--- a/drivers/tty/serial/mfd.c
+++ b/drivers/tty/serial/mfd.c@@ -47,6 +47,11 @@ #define mfd_readl(obj, offset) readl(obj->reg + offset) #define mfd_writel(obj, offset, val) writel(val, obj->reg + offset) +static int hsu_dma_enable; +module_param(hsu_dma_enable, int, 0); +MODULE_PARM_DESC(hsu_dma_enable, "It is a bitmap to set working mode, if \ +bit[x] is 1, then port[x] will work in DMA mode, otherwise in PIO mode."); + struct hsu_dma_buffer { u8 *buf; dma_addr_t dma_addr;
@@ -1367,6 +1372,12 @@ static void hsu_global_init(void) serial_hsu_ports[i] = uport; uport->index = i; + + if (hsu_dma_enable & (1<<i)) + uport->use_dma = 1; + else + uport->use_dma = 0; + uport++; }
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1.7.4.1