[PATCH 05/12] tty: amba-pl011: add register lookup table

[shijie.huang@arm.com (Huang Shijie)]

On Mon, Nov 16, 2015 at 05:40:26PM +0000, Russell King wrote:
Hi Russell,

> Add a register lookup table, which allows the register offsets to be
> adjusted on a per-port basis.
I met a console hang with my ARM juno-r1 board after the linux-next merge this patch.

The console hang like this:

==================================
on will start in   1 seconds
EFI stub: Booting Linux Kernel...
EFI stub: Using DTB from command line
EFI stub: Exiting boot services and installing virtual address map...
==================================

The console runs well if I revert this patch. Does anyone also meet the
same hang issue?

My kernel cmdline:
  console=ttyAMA0,115200 earlycon=pl011,0x7ff80000 root=/dev/sda1 rootwait verbose debug sky2.mac_address=0x00,0x02,0xF7,0x00,0x63,0x3C dtb=r1a57.dtb

thanks
Huang Shijie
>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
> ---
>  drivers/tty/serial/amba-pl011.c | 33 ++++++++++++++++++++++++-
>  drivers/tty/serial/amba-pl011.h | 53 ++++++++++++++++++++++-------------------
>  2 files changed, 60 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index 5ea5b0a3dbb9..628557f6a7a1 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -73,6 +73,34 @@
>  #define UART_DR_ERROR                (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
>  #define UART_DUMMY_DR_RX     (1 << 16)
>
> +static u16 pl011_std_offsets[REG_ARRAY_SIZE] = {
> +     [REG_DR] = UART01x_DR,
> +     [REG_ST_DMAWM] = ST_UART011_DMAWM,
> +     [REG_ST_TIMEOUT] = ST_UART011_TIMEOUT,
> +     [REG_FR] = UART01x_FR,
> +     [REG_ST_LCRH_RX] = ST_UART011_LCRH_RX,
> +     [REG_IBRD] = UART011_IBRD,
> +     [REG_FBRD] = UART011_FBRD,
> +     [REG_LCRH] = UART011_LCRH,
> +     [REG_ST_LCRH_TX] = ST_UART011_LCRH_TX,
> +     [REG_CR] = UART011_CR,
> +     [REG_IFLS] = UART011_IFLS,
> +     [REG_IMSC] = UART011_IMSC,
> +     [REG_RIS] = UART011_RIS,
> +     [REG_MIS] = UART011_MIS,
> +     [REG_ICR] = UART011_ICR,
> +     [REG_DMACR] = UART011_DMACR,
> +     [REG_ST_XFCR] = ST_UART011_XFCR,
> +     [REG_ST_XON1] = ST_UART011_XON1,
> +     [REG_ST_XON2] = ST_UART011_XON2,
> +     [REG_ST_XOFF1] = ST_UART011_XOFF1,
> +     [REG_ST_XOFF2] = ST_UART011_XOFF2,
> +     [REG_ST_ITCR] = ST_UART011_ITCR,
> +     [REG_ST_ITIP] = ST_UART011_ITIP,
> +     [REG_ST_ABCR] = ST_UART011_ABCR,
> +     [REG_ST_ABIMSC] = ST_UART011_ABIMSC,
> +};
> +
>  /* There is by now at least one vendor with differing details, so handle it */
>  struct vendor_data {
>       unsigned int            ifls;
> @@ -164,6 +192,7 @@ struct pl011_dmatx_data {
>   */
>  struct uart_amba_port {
>       struct uart_port        port;
> +     const u16               *reg_offset;
>       struct clk              *clk;
>       const struct vendor_data *vendor;
>       unsigned int            dmacr;          /* dma control reg */
> @@ -189,7 +218,7 @@ struct uart_amba_port {
>  static unsigned int pl011_reg_to_offset(const struct uart_amba_port *uap,
>       unsigned int reg)
>  {
> -     return reg;
> +     return uap->reg_offset[reg];
>  }
>
>  static unsigned int pl011_read(const struct uart_amba_port *uap,
> @@ -2397,6 +2426,7 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
>       if (IS_ERR(uap->clk))
>               return PTR_ERR(uap->clk);
>
> +     uap->reg_offset = pl011_std_offsets;
>       uap->vendor = vendor;
>       uap->lcrh_rx = vendor->lcrh_rx;
>       uap->lcrh_tx = vendor->lcrh_tx;
> @@ -2478,6 +2508,7 @@ static int sbsa_uart_probe(struct platform_device *pdev)
>       if (!uap)
>               return -ENOMEM;
>
> +     uap->reg_offset = pl011_std_offsets;
>       uap->vendor     = &vendor_sbsa;
>       uap->fifosize   = 32;
>       uap->port.irq   = platform_get_irq(pdev, 0);
> diff --git a/drivers/tty/serial/amba-pl011.h b/drivers/tty/serial/amba-pl011.h
> index b7eb1bc2fab9..0c6756dba2fe 100644
> --- a/drivers/tty/serial/amba-pl011.h
> +++ b/drivers/tty/serial/amba-pl011.h
> @@ -2,31 +2,34 @@
>  #define AMBA_PL011_H
>
>  enum {
> -     REG_DR = UART01x_DR,
> -     REG_ST_DMAWM = ST_UART011_DMAWM,
> -     REG_ST_TIMEOUT = ST_UART011_TIMEOUT,
> -     REG_FR = UART01x_FR,
> -     REG_ST_LCRH_RX = ST_UART011_LCRH_RX,
> -     REG_IBRD = UART011_IBRD,
> -     REG_FBRD = UART011_FBRD,
> -     REG_LCRH = UART011_LCRH,
> -     REG_ST_LCRH_TX = ST_UART011_LCRH_TX,
> -     REG_CR = UART011_CR,
> -     REG_IFLS = UART011_IFLS,
> -     REG_IMSC = UART011_IMSC,
> -     REG_RIS = UART011_RIS,
> -     REG_MIS = UART011_MIS,
> -     REG_ICR = UART011_ICR,
> -     REG_DMACR = UART011_DMACR,
> -     REG_ST_XFCR = ST_UART011_XFCR,
> -     REG_ST_XON1 = ST_UART011_XON1,
> -     REG_ST_XON2 = ST_UART011_XON2,
> -     REG_ST_XOFF1 = ST_UART011_XOFF1,
> -     REG_ST_XOFF2 = ST_UART011_XOFF2,
> -     REG_ST_ITCR = ST_UART011_ITCR,
> -     REG_ST_ITIP = ST_UART011_ITIP,
> -     REG_ST_ABCR = ST_UART011_ABCR,
> -     REG_ST_ABIMSC = ST_UART011_ABIMSC,
> +     REG_DR,
> +     REG_ST_DMAWM,
> +     REG_ST_TIMEOUT,
> +     REG_FR,
> +     REG_ST_LCRH_RX,
> +     REG_IBRD,
> +     REG_FBRD,
> +     REG_LCRH,
> +     REG_ST_LCRH_TX,
> +     REG_CR,
> +     REG_IFLS,
> +     REG_IMSC,
> +     REG_RIS,
> +     REG_MIS,
> +     REG_ICR,
> +     REG_DMACR,
> +     REG_ST_XFCR,
> +     REG_ST_XON1,
> +     REG_ST_XON2,
> +     REG_ST_XOFF1,
> +     REG_ST_XOFF2,
> +     REG_ST_ITCR,
> +     REG_ST_ITIP,
> +     REG_ST_ABCR,
> +     REG_ST_ABIMSC,
> +
> +     /* The size of the array - must be last */
> +     REG_ARRAY_SIZE,
>  };
>
>  #endif
> --
> 2.1.0
>
>
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