[U-Boot] [RFC][PATCH] ARM: mxs: Added application UART driver

Marek Vasut marex at denx.de
Sun Aug 11 21:19:44 CEST 2013 

Dear Andreas Wass,

> The driver is ported from a driver that was implemented
> using u-boot 2009.
> 
> The driver makes it possible to use a regular application UART as
> the U-Boot output console for MXS CPUs.
> 
> Signed-off-by: Andreas Wass <andreas.wass at dalelven.com>
> Cc: Fabio Estevam <fabio.estevam at freescale.com>
> Cc: Marek Vasut <marex at denx.de>
> ---
>  arch/arm/include/asm/arch-mxs/regs-uartapp.h | 321
> +++++++++++++++++++++++++++ drivers/serial/Makefile                      |
>   1 +
>  drivers/serial/mxs_auart.c                   | 118 ++++++++++
>  drivers/serial/serial.c                      |   3 +-
>  4 files changed, 442 insertions(+), 1 deletion(-)
>  create mode 100644 arch/arm/include/asm/arch-mxs/regs-uartapp.h
>  create mode 100644 drivers/serial/mxs_auart.c
> 
> diff --git a/arch/arm/include/asm/arch-mxs/regs-uartapp.h
> b/arch/arm/include/asm/arch-mxs/regs-uartapp.h new file mode 100644
> index 0000000..5e871b6
> --- /dev/null
> +++ b/arch/arm/include/asm/arch-mxs/regs-uartapp.h
> @@ -0,0 +1,321 @@
> +/*
> + * Freescale MXS UARTAPP Register Definitions
> + *
> + * Copyright (C) 2013 Andreas Wass <andreas.wass at dalelven.com>
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */

This is pulled from LTIB, right? Make sure to add proper comment about it (see 
the rest of the drivers).

> +#ifndef __ARCH_ARM___MXS_UARTAPP_H
> +#define __ARCH_ARM___MXS_UARTAPP_H
> +
> +#include <asm/imx-common/regs-common.h>
> +
> +#ifndef __ASSEMBLY__
> +struct mxs_uartapp_regs {
> +	mxs_reg_32(hw_uartapp_ctrl0)
> +	mxs_reg_32(hw_uartapp_ctrl1)
> +	mxs_reg_32(hw_uartapp_ctrl2)
> +	mxs_reg_32(hw_uartapp_linectrl)
> +	mxs_reg_32(hw_uartapp_linectrl2)
> +	mxs_reg_32(hw_uartapp_intr)
> +	mxs_reg_32(hw_uartapp_data)
> +	mxs_reg_32(hw_uartapp_stat)
> +	mxs_reg_32(hw_uartapp_debug)
> +	mxs_reg_32(hw_uartapp_version)
> +	mxs_reg_32(hw_uartapp_autobaud)
> +};
> +#endif
> +
> +
> +#define BM_UARTAPP_CTRL0_SFTRST				(1 << 31)
> +#define BM_UARTAPP_CTRL0_CLKGATE			(1 << 30)
> +#define BM_UARTAPP_CTRL0_RUN				(1 << 29)
> +#define BM_UARTAPP_CTRL0_RX_SOURCE			(1 << 28)
> +#define BM_UARTAPP_CTRL0_RXTO_ENABLE			(1 << 27)
> +#define BP_UARTAPP_CTRL0_RXTIMEOUT			(1 << 4)
> +#define BM_UARTAPP_CTRL0_RXTIMEOUT			0x07FF0000
> +#define BF_UARTAPP_CTRL0_RXTIMEOUT(v)  \
> +	(((v) << 16) & BM_UARTAPP_CTRL0_RXTIMEOUT)
> +#define BP_UARTAPP_CTRL0_XFER_COUNT			0
> +#define BM_UARTAPP_CTRL0_XFER_COUNT			0x0000FFFF
> +#define BF_UARTAPP_CTRL0_XFER_COUNT(v)  \
> +	(((v) << BP_UARTAPP_CTRL0_XFER_COUNT) & \
> +	 BM_UARTAPP_CTRL0_XFER_COUNT)

Can you rework it so the register/mask/offset definition pattern matches the 
rest of the files with registers?

- Drop the leading "B[A-Z]_"
- Add _MASK suffix to 'mask' vars (transfor the BM_ vars)
- The BF_ vars are not needed at all
- Add _OFFSET suffix to 'offset' vars (transform the BP_ vars)

It should be a simple 'sed' job.

[...]


> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index 697f2bb..4c45bfa 100644
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -38,6 +38,7 @@ COBJS-$(CONFIG_SCIF_CONSOLE) += serial_sh.o
>  COBJS-$(CONFIG_ZYNQ_SERIAL) += serial_zynq.o
>  COBJS-$(CONFIG_BFIN_SERIAL) += serial_bfin.o
>  COBJS-$(CONFIG_FSL_LPUART) += serial_lpuart.o
> +COBJS-$(CONFIG_MXS_AUART) += mxs_auart.o
> 
>  ifndef CONFIG_SPL_BUILD
>  COBJS-$(CONFIG_USB_TTY) += usbtty.o
> diff --git a/drivers/serial/mxs_auart.c b/drivers/serial/mxs_auart.c
> new file mode 100644
> index 0000000..a99dccf
> --- /dev/null
> +++ b/drivers/serial/mxs_auart.c
> @@ -0,0 +1,118 @@
> +/*
> + * Driver to use an application UART as console output for Freescale
> + * MXS devices.
> + *
> + * Copyright (C) 2013 Andreas Wass <andreas.wass at dalelven.com>
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +#include <common.h>
> +#include <asm/io.h>
> +#include <serial.h>
> +#include <linux/compiler.h>
> +#include <asm/arch/regs-base.h>
> +#include <asm/arch/regs-uartapp.h>
> +#include <asm/arch/sys_proto.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +#ifndef CONFIG_MXS_AUART_BASE
> +#error "CONFIG_MXS_AUART_BASE must be set to the base UART to use"
> +#endif
> +
> +#ifndef CONFIG_MXS_AUART_CLK
> +/* At least the i.MX28 always uses a 24MHz clock for AUART */
> +#define CONFIG_MXS_AUART_CLK 24000000
> +#endif

Just drop the leading CONFIG_ here and remove the ifdef, the AUART is always 
supplied from XTAL , so we dont need a config for this.

> +static struct mxs_uartapp_regs *get_uartapp_registers(void)
> +{
> +	return (struct mxs_uartapp_regs*)CONFIG_MXS_AUART_BASE;
> +}
> +
> +/*
> + * Set baud rate. The settings are always 8n1
> + */
> +void mxs_auart_setbrg(void)
> +{
> +	u32 div;
> +	u32 linectrl = 0;
> +	struct mxs_uartapp_regs *regs = get_uartapp_registers();
> +
> +	div = (CONFIG_MXS_AUART_CLK * 32) / CONFIG_BAUDRATE;
> +	linectrl |= BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(div & 0x3F);
> +	linectrl |= BF_UARTAPP_LINECTRL_BAUD_DIVINT(div >> 6);
> +	linectrl |= BF_UARTAPP_LINECTRL_WLEN(3);
> +	linectrl |= BM_UARTAPP_LINECTRL_FEN;
> +
> +	writel(linectrl, &regs->hw_uartapp_linectrl);
> +}
> +
> +int mxs_auart_init(void)
> +{
> +	struct mxs_uartapp_regs *regs = get_uartapp_registers();
> +	mxs_reset_block(&regs->hw_uartapp_ctrl0_reg);
> +	writel(0, &regs->hw_uartapp_intr);

You might want to comment on this a little.

> +	serial_setbrg();
> +
> +	writel(BM_UARTAPP_CTRL2_RTSEN |
> +			BM_UARTAPP_CTRL2_CTSEN |
> +			BM_UARTAPP_CTRL2_USE_LCR2,
> +			&regs->hw_uartapp_ctrl2_clr);
> +
> +	writel(BM_UARTAPP_CTRL2_RXE |
> +			BM_UARTAPP_CTRL2_TXE |
> +			BM_UARTAPP_CTRL2_UARTEN,
> +			&regs->hw_uartapp_ctrl2_set);
> +	return 0;
> +}

[...]

> diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
> index 6730135..2bc42a7 100644
> --- a/drivers/serial/serial.c
> +++ b/drivers/serial/serial.c
> @@ -159,6 +159,7 @@ serial_initfunc(pl01x_serial_initialize);
>  serial_initfunc(s3c44b0_serial_initialize);
>  serial_initfunc(sa1100_serial_initialize);
>  serial_initfunc(sh_serial_initialize);
> +serial_initfunc(mxs_auart_initialize);
> 
>  /**
>   * serial_register() - Register serial driver with serial driver core
> @@ -251,7 +252,7 @@ void serial_initialize(void)
>  	s3c44b0_serial_initialize();
>  	sa1100_serial_initialize();
>  	sh_serial_initialize();
> -
> +	mxs_auart_initialize();

Keep the newline here please.

>  	serial_assign(default_serial_console()->name);
>  }

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