From: Fabio Estevam <festevam@gmail.com>
To: Clemens Gruber <clemens.gruber@pqgruber.com>
Cc: "linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Sascha Hauer" <s.hauer@pengutronix.de>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Nandor Han" <nandor.han@ge.com>,
"Lucas Stach" <l.stach@pengutronix.de>,
"Fabio Estevam" <fabio.estevam@freescale.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: imx: RS-485 problems during TX, maybe DMA related
Date: Fri, 6 Jan 2017 22:31:16 -0200 [thread overview]
Message-ID: <CAOMZO5CywajwZEL8K2ATfS80WzqY69YVX+3S7hq9_HmNdNAwaw@mail.gmail.com> (raw)
In-Reply-To: <20170106225026.GA3804@archie.localdomain>
Hi Clemens,
On Fri, Jan 6, 2017 at 8:50 PM, Clemens Gruber
<clemens.gruber@pqgruber.com> wrote:
> But according to the i.MX Pins tool, they can be muxed vice-versa too.
> So if you connected the transceiver-enable to ball L4 (CSI0_DAT16), you
> could mux MX6QDL_PAD_CSI0_DAT16__UART4_CTS_B and
> MX6QDL_PAD_CSI0_DAT17__UART4_RTS_B instead?
Yes, I have tried like this:
&uart4 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart4>;
uart-has-rtscts;
status = "okay";
};
pinctrl_uart4: uart4grp {
fsl,pins = <
MX6QDL_PAD_CSI0_DAT12__UART4_TX_DATA 0x1b0b1
MX6QDL_PAD_KEY_ROW0__UART4_RX_DATA 0x1b0b1
MX6QDL_PAD_CSI0_DAT16__UART4_CTS_B 0x1b0b1
>;
};
In this case the DE pin of the rs485 transceiver is always at 0 then
RX works and TX does not.
Then I tried to use a gpio for controling the rts line:
&uart4 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart4>;
rts-gpios = <&gpio6 2 GPIO_ACTIVE_HIGH>;
status = "okay";
};
pinctrl_uart4: uart4grp {
fsl,pins = <
MX6QDL_PAD_CSI0_DAT12__UART4_TX_DATA 0x1b0b1
MX6QDL_PAD_KEY_ROW0__UART4_RX_DATA 0x1b0b1
MX6QDL_PAD_CSI0_DAT16__GPIO6_IO02 0x1b0b1
>;
}
In this case the DE pin of the rs485 transceiver is always at 1, then
TX works and RX does not.
So I was never able to observe the DE pin toggling correctly.
Maybe you could share your userspace application with me offline?
Thanks
next prev parent reply other threads:[~2017-01-07 0:31 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-04 16:00 imx: RS-485 problems during TX, maybe DMA related Clemens Gruber
2017-01-06 21:22 ` Fabio Estevam
2017-01-06 22:50 ` Clemens Gruber
2017-01-07 0:31 ` Fabio Estevam [this message]
2017-01-07 13:45 ` Clemens Gruber
2017-01-07 14:57 ` Fabio Estevam
2017-01-07 15:34 ` Clemens Gruber
2017-01-07 16:48 ` Fabio Estevam
2017-01-07 20:59 ` Clemens Gruber
2017-01-07 21:43 ` Fabio Estevam
2017-01-07 23:06 ` Clemens Gruber
2017-01-08 2:30 ` Fabio Estevam
2017-01-08 18:06 ` Clemens Gruber
2017-01-08 21:46 ` Fabio Estevam
2017-01-11 0:33 ` Clemens Gruber
2017-01-11 11:51 ` Fabio Estevam
2017-01-08 15:12 ` Fabio Estevam
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