On 12/20/2012 09:18 PM, Laxman Dewangan wrote: > On Thursday 20 December 2012 10:33 PM, Stephen Warren wrote: >> On 12/19/2012 11:15 PM, Laxman Dewangan wrote: >>> On Wednesday 19 December 2012 10:30 PM, Stephen Warren wrote: >>>> On 12/18/2012 11:31 PM, Laxman Dewangan wrote: >>>>> Add APB DMA requestor and serial aliases for serial controller. >>>>> There will be two serial driver i.e. 8250 based simple serial driver >>>>> and APB DMA based serial driver for higher baudrate and performace. ... >>>> This patch seems to do two things: ... >>>> 2) Add aliases for the serial ports. I have no idea why this is useful. >>> Serial aliases are added because we want to get the port number like >>> /dev/ttyTHS0, /d/ttyTHS2 etc. The uarta should be /dev/ttyTHS0 and >>> uartc should be /dev/ttyTHS2. The port number can be found using aliases >>> and of_alias_get_id() in driver file: >>> >>> port_number = of_alias_get_id(np, "serial"); >> >> Oh, I see. I guess the aliases make sense then. >> >> But, wouldn't you only add aliases for the specific UARTs that are in >> use on a particular board (so put them in tegraNN-board.dts) rather than >> all UARTs on Tegra (i.e. the current patch which puts them into >> tegraNN.dtsi)? > > I like to have this in tegraN N.dtsi file becasue: > - This policy is not going to change the board to board. For high speed > driver the uarta will be ttyTHS0 and uartb ttyTHS1. Sure it is. Since the board files select which UARTs use the low-speed driver vs. the high-speed driver by overriding the compatible value, each board will have a different subset of UARTs which use the high speed driver and hence which use the aliases. Don't you want to end up with /dev/ttyHS0 on each board, rather than ending up with a "random" device node name depending on which UART the board designer picked for the high speed device? -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
