Subject: [PATCH v2] serial: amba-pl011: complete support to ZTE uart

From: [email-masked] (Greg KH)
Date: Thu, 28 Apr 2016 13:11:06 -0700

On Mon, Apr 25, 2016 at 02:53:02PM +0800, Jun Nie wrote:
> 2016-04-12 21:01 GMT+08:00 Jun Nie <[email-masked]>:
> > On 2016?04?01? 17:53, Jun Nie wrote:
> >>
> >> 2016-03-23 15:12 GMT+08:00 Jun Nie <[email-masked]>:
> >>>
> >>> Complete support to ZTE uart with adding specific registers
> >>> mask.
> >>> We use a magic amba periphid value as pl011 device on ZTE
> >>> does not have a periphid value in register. The magic value
> >>> should also be feed via device tree "arm,primecell-periphid"
> >>> property to match pl011 driver and get ZTE uart data.
> >>>
> >>> Signed-off-by: Jun Nie <[email-masked]>
> >>> ---
> >>>   drivers/tty/serial/amba-pl011.c | 73
> >>> +++++++++++++++++++++++++++++++++--------
> >>>   include/linux/amba/serial.h     |  4 +++
> >>>   2 files changed, 64 insertions(+), 13 deletions(-)
> >>>
> >>> diff --git a/drivers/tty/serial/amba-pl011.c
> >>> b/drivers/tty/serial/amba-pl011.c
> >>> index 7c198e0..696ee0c 100644
> >>> --- a/drivers/tty/serial/amba-pl011.c
> >>> +++ b/drivers/tty/serial/amba-pl011.c
> >>> @@ -93,6 +93,10 @@ static u16 pl011_std_offsets[REG_ARRAY_SIZE] = {
> >>>   struct vendor_data {
> >>>          const u16               *reg_offset;
> >>>          unsigned int            ifls;
> >>> +       unsigned int            fr_busy;
> >>> +       unsigned int            fr_dsr;
> >>> +       unsigned int            fr_cts;
> >>> +       unsigned int            fr_ri;
> >>>          bool                    access_32b;
> >>>          bool                    oversampling;
> >>>          bool                    dma_threshold;
> >>> @@ -111,6 +115,10 @@ static unsigned int get_fifosize_arm(struct
> >>> amba_device *dev)
> >>>   static struct vendor_data vendor_arm = {
> >>>          .reg_offset             = pl011_std_offsets,
> >>>          .ifls                   = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
> >>> +       .fr_busy                = UART01x_FR_BUSY,
> >>> +       .fr_dsr                 = UART01x_FR_DSR,
> >>> +       .fr_cts                 = UART01x_FR_CTS,
> >>> +       .fr_ri                  = UART011_FR_RI,
> >>>          .oversampling           = false,
> >>>          .dma_threshold          = false,
> >>>          .cts_event_workaround   = false,
> >>> @@ -121,6 +129,10 @@ static struct vendor_data vendor_arm = {
> >>>
> >>>   static struct vendor_data vendor_sbsa = {
> >>>          .reg_offset             = pl011_std_offsets,
> >>> +       .fr_busy                = UART01x_FR_BUSY,
> >>> +       .fr_dsr                 = UART01x_FR_DSR,
> >>> +       .fr_cts                 = UART01x_FR_CTS,
> >>> +       .fr_ri                  = UART011_FR_RI,
> >>>          .oversampling           = false,
> >>>          .dma_threshold          = false,
> >>>          .cts_event_workaround   = false,
> >>> @@ -163,6 +175,10 @@ static unsigned int get_fifosize_st(struct
> >>> amba_device *dev)
> >>>   static struct vendor_data vendor_st = {
> >>>          .reg_offset             = pl011_st_offsets,
> >>>          .ifls                   =
> >>> UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
> >>> +       .fr_busy                = UART01x_FR_BUSY,
> >>> +       .fr_dsr                 = UART01x_FR_DSR,
> >>> +       .fr_cts                 = UART01x_FR_CTS,
> >>> +       .fr_ri                  = UART011_FR_RI,
> >>>          .oversampling           = true,
> >>>          .dma_threshold          = true,
> >>>          .cts_event_workaround   = true,
> >>> @@ -187,11 +203,25 @@ static const u16 pl011_zte_offsets[REG_ARRAY_SIZE]
> >>> = {
> >>>          [REG_DMACR] = ZX_UART011_DMACR,
> >>>   };
> >>>
> >>> +static unsigned int get_fifosize_zte(struct amba_device *dev)
> >>> +{
> >>> +       return 16;
> >>> +}
> >>> +
> >>>   static struct vendor_data vendor_zte __maybe_unused = {
> >>>          .reg_offset             = pl011_zte_offsets,
> >>>          .access_32b             = true,
> >>>          .ifls                   = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
> >>> -       .get_fifosize           = get_fifosize_arm,
> >>> +       .fr_busy                = ZX_UART01x_FR_BUSY,
> >>> +       .fr_dsr                 = ZX_UART01x_FR_DSR,
> >>> +       .fr_cts                 = ZX_UART01x_FR_CTS,
> >>> +       .fr_ri                  = ZX_UART011_FR_RI,
> >>> +       .oversampling           = false,
> >>> +       .dma_threshold          = false,
> >>> +       .cts_event_workaround   = false,
> >>> +       .always_enabled         = false,
> >>> +       .fixed_options          = false,
> >>> +       .get_fifosize           = get_fifosize_zte,
> >>>   };
> >>>
> >>>   /* Deals with DMA transactions */
> >>> @@ -236,6 +266,10 @@ struct uart_amba_port {
> >>>          unsigned int            im;             /* interrupt mask */
> >>>          unsigned int            old_status;
> >>>          unsigned int            fifosize;       /* vendor-specific */
> >>> +       unsigned int            fr_busy;        /* vendor-specific */
> >>> +       unsigned int            fr_dsr;         /* vendor-specific */
> >>> +       unsigned int            fr_cts;         /* vendor-specific */
> >>> +       unsigned int            fr_ri;          /* vendor-specific */
> >>>          unsigned int            old_cr;         /* state during shutdown
> >>> */
> >>>          bool                    autorts;
> >>>          unsigned int            fixed_baud;     /* vendor-set fixed baud
> >>> rate */
> >>> @@ -1166,7 +1200,7 @@ static void pl011_dma_shutdown(struct
> >>> uart_amba_port *uap)
> >>>                  return;
> >>>
> >>>          /* Disable RX and TX DMA */
> >>> -       while (pl011_read(uap, REG_FR) & UART01x_FR_BUSY)
> >>> +       while (pl011_read(uap, REG_FR) & uap->fr_busy)
> >>>                  cpu_relax();
> >>>
> >>>          spin_lock_irq(&uap->port.lock);
> >>> @@ -1415,11 +1449,11 @@ static void pl011_modem_status(struct
> >>> uart_amba_port *uap)
> >>>          if (delta & UART01x_FR_DCD)
> >>>                  uart_handle_dcd_change(&uap->port, status &
> >>> UART01x_FR_DCD);
> >>>
> >>> -       if (delta & UART01x_FR_DSR)
> >>> +       if (delta & uap->fr_dsr)
> >>>                  uap->port.icount.dsr++;
> >>>
> >>> -       if (delta & UART01x_FR_CTS)
> >>> -               uart_handle_cts_change(&uap->port, status &
> >>> UART01x_FR_CTS);
> >>> +       if (delta & uap->fr_cts)
> >>> +               uart_handle_cts_change(&uap->port, status & uap->fr_cts);
> >>>
> >>>          wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
> >>>   }
> >>> @@ -1492,7 +1526,7 @@ static unsigned int pl011_tx_empty(struct uart_port
> >>> *port)
> >>>          struct uart_amba_port *uap =
> >>>              container_of(port, struct uart_amba_port, port);
> >>>          unsigned int status = pl011_read(uap, REG_FR);
> >>> -       return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 :
> >>> TIOCSER_TEMT;
> >>> +       return status & (uap->fr_busy | UART01x_FR_TXFF) ? 0 :
> >>> TIOCSER_TEMT;
> >>>   }
> >>>
> >>>   static unsigned int pl011_get_mctrl(struct uart_port *port)
> >>> @@ -1507,9 +1541,9 @@ static unsigned int pl011_get_mctrl(struct
> >>> uart_port *port)
> >>>                  result |= tiocmbit
> >>>
> >>>          TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
> >>> -       TIOCMBIT(UART01x_FR_DSR, TIOCM_DSR);
> >>> -       TIOCMBIT(UART01x_FR_CTS, TIOCM_CTS);
> >>> -       TIOCMBIT(UART011_FR_RI, TIOCM_RNG);
> >>> +       TIOCMBIT(uap->fr_dsr, TIOCM_DSR);
> >>> +       TIOCMBIT(uap->fr_cts, TIOCM_CTS);
> >>> +       TIOCMBIT(uap->fr_ri, TIOCM_RNG);
> >>>   #undef TIOCMBIT
> >>>          return result;
> >>>   }
> >>> @@ -2086,7 +2120,7 @@ static int pl011_verify_port(struct uart_port
> >>> *port, struct serial_struct *ser)
> >>>          return ret;
> >>>   }
> >>>
> >>> -static struct uart_ops amba_pl011_pops = {
> >>> +static const struct uart_ops amba_pl011_pops = {
> >>>          .tx_empty       = pl011_tx_empty,
> >>>          .set_mctrl      = pl011_set_mctrl,
> >>>          .get_mctrl      = pl011_get_mctrl,
> >>> @@ -2190,7 +2224,7 @@ pl011_console_write(struct console *co, const char
> >>> *s, unsigned int count)
> >>>           *      Finally, wait for transmitter to become empty
> >>>           *      and restore the TCR
> >>>           */
> >>> -       while (pl011_read(uap, REG_FR) & UART01x_FR_BUSY)
> >>> +       while (pl011_read(uap, REG_FR) & uap->fr_busy)
> >>>                  cpu_relax();
> >>>          if (!uap->vendor->always_enabled)
> >>>                  pl011_write(old_cr, uap, REG_CR);
> >>> @@ -2472,8 +2506,12 @@ static int pl011_probe(struct amba_device *dev,
> >>> const struct amba_id *id)
> >>>                  return PTR_ERR(uap->clk);
> >>>
> >>>          uap->reg_offset = vendor->reg_offset;
> >>> -       uap->vendor = vendor;
> >>> -       uap->fifosize = vendor->get_fifosize(dev);
> >>> +       uap->vendor     = vendor;
> >>> +       uap->fifosize   = vendor->get_fifosize(dev);
> >>> +       uap->fr_busy    = vendor->fr_busy;
> >>> +       uap->fr_dsr     = vendor->fr_dsr;
> >>> +       uap->fr_cts     = vendor->fr_cts;
> >>> +       uap->fr_ri      = vendor->fr_ri;
> >>>          uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
> >>>          uap->port.irq = dev->irq[0];
> >>>          uap->port.ops = &amba_pl011_pops;
> >>> @@ -2555,6 +2593,10 @@ static int sbsa_uart_probe(struct platform_device
> >>> *pdev)
> >>>          uap->reg_offset = vendor_sbsa.reg_offset;
> >>>          uap->vendor     = &vendor_sbsa;
> >>>          uap->fifosize   = 32;
> >>> +       uap->fr_busy    = vendor_sbsa.fr_busy;
> >>> +       uap->fr_dsr     = vendor_sbsa.fr_dsr;
> >>> +       uap->fr_cts     = vendor_sbsa.fr_cts;
> >>> +       uap->fr_ri      = vendor_sbsa.fr_ri;
> >>>          uap->port.iotype = vendor_sbsa.access_32b ? UPIO_MEM32 :
> >>> UPIO_MEM;
> >>>          uap->port.irq   = platform_get_irq(pdev, 0);
> >>>          uap->port.ops   = &sbsa_uart_pops;
> >>> @@ -2615,6 +2657,11 @@ static struct amba_id pl011_ids[] = {
> >>>                  .mask   = 0x00ffffff,
> >>>                  .data   = &vendor_st,
> >>>          },
> >>> +       {
> >>> +               .id     = 0xfefefe,
> >>> +               .mask   = 0xffffff,
> >>> +               .data   = &vendor_zte,
> >>> +       },
> >>>          { 0, 0 },
> >>>   };
> >>>
> >>> diff --git a/include/linux/amba/serial.h b/include/linux/amba/serial.h
> >>> index d76a19b..750f2ef 100644
> >>> --- a/include/linux/amba/serial.h
> >>> +++ b/include/linux/amba/serial.h
> >>> @@ -103,6 +103,10 @@
> >>>   #define UART01x_FR_DSR                 0x002
> >>>   #define UART01x_FR_CTS                 0x001
> >>>   #define UART01x_FR_TMSK                (UART01x_FR_TXFF +
> >>> UART01x_FR_BUSY)
> >>> +#define ZX_UART01x_FR_BUSY     0x300
> >>> +#define ZX_UART01x_FR_DSR      0x008
> >>> +#define ZX_UART01x_FR_CTS      0x002
> >>> +#define ZX_UART011_FR_RI       0x001
> >>>
> >>>   #define UART011_CR_CTSEN       0x8000  /* CTS hardware flow control */
> >>>   #define UART011_CR_RTSEN       0x4000  /* RTS hardware flow control */
> >>> --
> >>> 1.9.1
> >>>
> >
> > Russell,
> >
> > Do you have any comments to these change?
> >
> > Jun
> 
> Greg,
> 
> Do you have any idea on how to drive review on this patch? Seems
> maintainer Russell is too busy and missing for this thread and others
> do not have comments. Your comments are appreciated!

I would like to get Russell's opinion of this before merging it.

thanks,

greg k-h