Date: Tue, 6 Aug 2019 17:44:49 +0200 From: Milan Obuch <freebsd-arm@dino.sk> To: freebsd-arm@freebsd.org Subject: Re: Attempt to use uart0 on Zybo Z7 Message-ID: <20190806174449.24493f85@zeta.dino.sk> In-Reply-To: <20190806172337.31f87439@zeta.dino.sk> References: <20190803091019.2d067756@zeta.dino.sk> <20190806161415.4be2a991@zeta.dino.sk> <20190806172337.31f87439@zeta.dino.sk>
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On Tue, 6 Aug 2019 17:23:37 +0200 Milan Obuch <freebsd-arm@dino.sk> wrote: > On Tue, 6 Aug 2019 16:14:15 +0200 > Milan Obuch <freebsd-arm@dino.sk> wrote: > > > On Sat, 3 Aug 2019 09:10:19 +0200 > > Milan Obuch <freebsd-arm@dino.sk> wrote: > > > > > Hi, > > > > > > Zynq SoC has several peripherals available on its PS/ARM side of > > > thing. Currently supported list contains UART, USB, ethernet, SDIO > > > and GPIO. No driver yet for SPI, I2C and CAN. > > > > > > Available GPIO pins are on JF6 (MIO pmod connector), I tested them > > > as inputs and they are working as expected. > > > > After some testing I found a way to enable uart0. Currently only > devices initialized by u-boot could be used, I think, and uart0 had no > clocks initialized. Now my hardware loopback works, I am going to > connect TTL-RS232 level converter and/or USB/UART convertor to check > from other box. > > Summary: > > zy7_slcr_unlock(sc); > WR4(sc, ZY7_SLCR_MIO_PIN(14), 0x16E1); > WR4(sc, ZY7_SLCR_MIO_PIN(15), 0x16E0); > > j = RD4(sc, ZY7_SLCR_APER_CLK_CTRL); > WR4(sc, ZY7_SLCR_APER_CLK_CTRL, j | > ZY7_SLCR_APER_CLK_CTRL_UART0_CPU_1XCLKACT); > > j = RD4(sc, ZY7_SLCR_UART_CLK_CTRL); > WR4(sc, ZY7_SLCR_UART_CLK_CTRL, j | 1); > > This makes necessary MIO routing change, enables APB and refererence > clocks for uart0. I put this at end of zy7_slcr_attach() function as > mentioned in original mail. > Testing with TTL-RS232 level converter: it works almost perfect, just bit rate is doubled. On Zybo I use cu -l /dev/cuau0 -s 9600 and on the other box cu -l /dev/cuaU3 -s 19200 and then I see all I type over the wire, on the other end, correctly. Milan
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