[PATCH v13 2/5] uart: pl011: Introduce register accessor
Andre Przywara
andre.przywara at arm.com
Fri Sep 18 03:51:57 PDT 2015
Hi Jun,
(CC:ing linux-arm-kernel to catch a broader audience)
I assume this is the latest version on the list? If I got the outcome of
the discussion right, we do more review on this and merge an improved
version later on.
On 31/07/15 08:49, Jun Nie wrote:
> Introduce register accessor to ease loop up table access
> in later patch.
Wouldn't it make sense to make this the first patch? Then you could get
rid of patching your own previous patch, possibly also joining patch 1/5
and 3/5 into a new 2/4.
More comments inline ...
> Signed-off-by: Jun Nie <jun.nie at linaro.org>
> Reviewed-by: Peter Hurley <peter at hurleysoftware.com>
> ---
> drivers/tty/serial/amba-pl011.c | 263 +++++++++++++++++++++-------------------
> 1 file changed, 141 insertions(+), 122 deletions(-)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index ee57e2b..29a291d 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -85,23 +85,26 @@ struct vendor_data {
> unsigned int (*get_fifosize)(struct amba_device *dev);
> };
>
> +/* Max address offset of register in use is 0x48 */
> +#define REG_NR (0x48 >> 2)
> +#define IDX(x) (x >> 2)
> enum reg_idx {
> - REG_DR = UART01x_DR,
> - REG_RSR = UART01x_RSR,
> - REG_ST_DMAWM = ST_UART011_DMAWM,
> - REG_FR = UART01x_FR,
> - REG_ST_LCRH_RX = ST_UART011_LCRH_RX,
> - REG_ILPR = UART01x_ILPR,
> - REG_IBRD = UART011_IBRD,
> - REG_FBRD = UART011_FBRD,
> - REG_LCRH = UART011_LCRH,
> - 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_DR = IDX(UART01x_DR),
> + REG_RSR = IDX(UART01x_RSR),
> + REG_ST_DMAWM = IDX(ST_UART011_DMAWM),
> + REG_FR = IDX(UART01x_FR),
> + REG_ST_LCRH_RX = IDX(ST_UART011_LCRH_RX),
> + REG_ILPR = IDX(UART01x_ILPR),
> + REG_IBRD = IDX(UART011_IBRD),
> + REG_FBRD = IDX(UART011_FBRD),
> + REG_LCRH = IDX(UART011_LCRH),
> + REG_CR = IDX(UART011_CR),
> + REG_IFLS = IDX(UART011_IFLS),
> + REG_IMSC = IDX(UART011_IMSC),
> + REG_RIS = IDX(UART011_RIS),
> + REG_MIS = IDX(UART011_MIS),
> + REG_ICR = IDX(UART011_ICR),
> + REG_DMACR = IDX(UART011_DMACR),
> };
>
> static unsigned int get_fifosize_arm(struct amba_device *dev)
> @@ -203,6 +206,24 @@ struct uart_amba_port {
> #endif
> };
>
> +static unsigned int pl011_readw(struct uart_amba_port *uap, int index)
> +{
> + WARN_ON(index > REG_NR);
> + return readw_relaxed(uap->port.membase + (index << 2));
> +}
> +
> +static void pl011_writew(struct uart_amba_port *uap, int val, int index)
> +{
> + WARN_ON(index > REG_NR);
> + writew_relaxed(val, uap->port.membase + (index << 2));
> +}
I wonder if you could rename those to pl011_{read,write}, respectively
(loosing the "w" suffix).
The SBSA UART spec reads as the registers are actually accessible via
32-bit accesses and rumour has it that there are implementations which
rely on that and don't work with ldrh/strh.
I am still waiting for reports about actual hardware to fail, but we
might be forced to change the access width to 32-bit for the SBSA subset
in the future. So having wrapper functions would make that change much
easier, but having them without a suffix from the beginning would even
be better, as I wouldn't be bothered to rename them later on.
> +
> +static void pl011_writeb(struct uart_amba_port *uap, u8 val, int index)
> +{
> + WARN_ON(index > REG_NR);
> + writeb_relaxed(val, uap->port.membase + (index << 2));
> +}
> +
As you already know, this one can go, as we don't need it.
> /*
> * Reads up to 256 characters from the FIFO or until it's empty and
> * inserts them into the TTY layer. Returns the number of characters
> @@ -215,12 +236,12 @@ static int pl011_fifo_to_tty(struct uart_amba_port *uap)
> int fifotaken = 0;
>
> while (max_count--) {
> - status = readw(uap->port.membase + REG_FR);
> + status = pl011_readw(uap, REG_FR);
> if (status & UART01x_FR_RXFE)
> break;
>
> /* Take chars from the FIFO and update status */
> - ch = readw(uap->port.membase + REG_DR) |
> + ch = pl011_readw(uap, REG_DR) |
> UART_DUMMY_DR_RX;
> flag = TTY_NORMAL;
> uap->port.icount.rx++;
> @@ -457,7 +478,7 @@ static void pl011_dma_tx_callback(void *data)
>
> dmacr = uap->dmacr;
> uap->dmacr = dmacr & ~UART011_TXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
>
> /*
> * If TX DMA was disabled, it means that we've stopped the DMA for
> @@ -571,7 +592,7 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
> dma_dev->device_issue_pending(chan);
>
> uap->dmacr |= UART011_TXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> uap->dmatx.queued = true;
>
> /*
> @@ -607,9 +628,9 @@ static bool pl011_dma_tx_irq(struct uart_amba_port *uap)
> */
> if (uap->dmatx.queued) {
> uap->dmacr |= UART011_TXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> uap->im &= ~UART011_TXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> return true;
> }
>
> @@ -619,7 +640,7 @@ static bool pl011_dma_tx_irq(struct uart_amba_port *uap)
> */
> if (pl011_dma_tx_refill(uap) > 0) {
> uap->im &= ~UART011_TXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> return true;
> }
> return false;
> @@ -633,7 +654,7 @@ static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
> {
> if (uap->dmatx.queued) {
> uap->dmacr &= ~UART011_TXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> }
> }
>
> @@ -659,14 +680,12 @@ static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
> if (!uap->dmatx.queued) {
> if (pl011_dma_tx_refill(uap) > 0) {
> uap->im &= ~UART011_TXIM;
> - writew(uap->im, uap->port.membase +
> - REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> } else
> ret = false;
> } else if (!(uap->dmacr & UART011_TXDMAE)) {
> uap->dmacr |= UART011_TXDMAE;
> - writew(uap->dmacr,
> - uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> }
> return ret;
> }
> @@ -677,9 +696,9 @@ static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
> */
> dmacr = uap->dmacr;
> uap->dmacr &= ~UART011_TXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
>
> - if (readw(uap->port.membase + REG_FR) & UART01x_FR_TXFF) {
> + if (pl011_readw(uap, REG_FR) & UART01x_FR_TXFF) {
> /*
> * No space in the FIFO, so enable the transmit interrupt
> * so we know when there is space. Note that once we've
> @@ -688,13 +707,13 @@ static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
> return false;
> }
>
> - writew(uap->port.x_char, uap->port.membase + REG_DR);
> + pl011_writew(uap, uap->port.x_char, REG_DR);
> uap->port.icount.tx++;
> uap->port.x_char = 0;
>
> /* Success - restore the DMA state */
> uap->dmacr = dmacr;
> - writew(dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, dmacr, REG_DMACR);
>
> return true;
> }
> @@ -722,7 +741,7 @@ __acquires(&uap->port.lock)
> DMA_TO_DEVICE);
> uap->dmatx.queued = false;
> uap->dmacr &= ~UART011_TXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> }
> }
>
> @@ -762,11 +781,11 @@ static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
> dma_async_issue_pending(rxchan);
>
> uap->dmacr |= UART011_RXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> uap->dmarx.running = true;
>
> uap->im &= ~UART011_RXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
>
> return 0;
> }
> @@ -824,8 +843,9 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap,
> */
> if (dma_count == pending && readfifo) {
> /* Clear any error flags */
> - writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS,
> - uap->port.membase + REG_ICR);
> + pl011_writew(uap,
> + UART011_OEIS | UART011_BEIS | UART011_PEIS
> + | UART011_FEIS, REG_ICR);
>
> /*
> * If we read all the DMA'd characters, and we had an
> @@ -873,7 +893,7 @@ static void pl011_dma_rx_irq(struct uart_amba_port *uap)
>
> /* Disable RX DMA - incoming data will wait in the FIFO */
> uap->dmacr &= ~UART011_RXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> uap->dmarx.running = false;
>
> pending = sgbuf->sg.length - state.residue;
> @@ -893,7 +913,7 @@ static void pl011_dma_rx_irq(struct uart_amba_port *uap)
> dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
> "fall back to interrupt mode\n");
> uap->im |= UART011_RXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> }
> }
>
> @@ -941,7 +961,7 @@ static void pl011_dma_rx_callback(void *data)
> dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
> "fall back to interrupt mode\n");
> uap->im |= UART011_RXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> }
> }
>
> @@ -954,7 +974,7 @@ static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
> {
> /* FIXME. Just disable the DMA enable */
> uap->dmacr &= ~UART011_RXDMAE;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> }
>
> /*
> @@ -998,7 +1018,7 @@ static void pl011_dma_rx_poll(unsigned long args)
> spin_lock_irqsave(&uap->port.lock, flags);
> pl011_dma_rx_stop(uap);
> uap->im |= UART011_RXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> spin_unlock_irqrestore(&uap->port.lock, flags);
>
> uap->dmarx.running = false;
> @@ -1060,7 +1080,7 @@ static void pl011_dma_startup(struct uart_amba_port *uap)
> skip_rx:
> /* Turn on DMA error (RX/TX will be enabled on demand) */
> uap->dmacr |= UART011_DMAONERR;
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
>
> /*
> * ST Micro variants has some specific dma burst threshold
> @@ -1068,9 +1088,9 @@ skip_rx:
> * be issued above/below 16 bytes.
> */
> if (uap->vendor->dma_threshold)
> - writew(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16,
> - uap->port.membase + REG_ST_DMAWM);
> -
> + pl011_writew(uap,
> + ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16,
> + REG_ST_DMAWM);
>
> if (uap->using_rx_dma) {
> if (pl011_dma_rx_trigger_dma(uap))
> @@ -1095,12 +1115,12 @@ static void pl011_dma_shutdown(struct uart_amba_port *uap)
> return;
>
> /* Disable RX and TX DMA */
> - while (readw(uap->port.membase + REG_FR) & UART01x_FR_BUSY)
> + while (pl011_readw(uap, REG_FR) & UART01x_FR_BUSY)
> barrier();
>
> spin_lock_irq(&uap->port.lock);
> uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE);
> - writew(uap->dmacr, uap->port.membase + REG_DMACR);
> + pl011_writew(uap, uap->dmacr, REG_DMACR);
> spin_unlock_irq(&uap->port.lock);
>
> if (uap->using_tx_dma) {
> @@ -1201,7 +1221,7 @@ static void pl011_stop_tx(struct uart_port *port)
> container_of(port, struct uart_amba_port, port);
>
> uap->im &= ~UART011_TXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> pl011_dma_tx_stop(uap);
> }
>
> @@ -1211,7 +1231,7 @@ static void pl011_tx_chars(struct uart_amba_port *uap, bool from_irq);
> static void pl011_start_tx_pio(struct uart_amba_port *uap)
> {
> uap->im |= UART011_TXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> pl011_tx_chars(uap, false);
> }
>
> @@ -1231,7 +1251,7 @@ static void pl011_stop_rx(struct uart_port *port)
>
> uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM|
> UART011_PEIM|UART011_BEIM|UART011_OEIM);
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
>
> pl011_dma_rx_stop(uap);
> }
> @@ -1242,7 +1262,7 @@ static void pl011_enable_ms(struct uart_port *port)
> container_of(port, struct uart_amba_port, port);
>
> uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> }
>
> static void pl011_rx_chars(struct uart_amba_port *uap)
> @@ -1262,7 +1282,7 @@ __acquires(&uap->port.lock)
> dev_dbg(uap->port.dev, "could not trigger RX DMA job "
> "fall back to interrupt mode again\n");
> uap->im |= UART011_RXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> } else {
> #ifdef CONFIG_DMA_ENGINE
> /* Start Rx DMA poll */
> @@ -1283,10 +1303,10 @@ static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
> bool from_irq)
> {
> if (unlikely(!from_irq) &&
> - readw(uap->port.membase + REG_FR) & UART01x_FR_TXFF)
> + pl011_readw(uap, REG_FR) & UART01x_FR_TXFF)
> return false; /* unable to transmit character */
>
> - writew(c, uap->port.membase + REG_DR);
> + pl011_writew(uap, c, REG_DR);
> uap->port.icount.tx++;
>
> return true;
> @@ -1333,7 +1353,7 @@ static void pl011_modem_status(struct uart_amba_port *uap)
> {
> unsigned int status, delta;
>
> - status = readw(uap->port.membase + REG_FR) & UART01x_FR_MODEM_ANY;
> + status = pl011_readw(uap, REG_FR) & UART01x_FR_MODEM_ANY;
>
> delta = status ^ uap->old_status;
> uap->old_status = status;
> @@ -1361,15 +1381,15 @@ static void check_apply_cts_event_workaround(struct uart_amba_port *uap)
> return;
>
> /* workaround to make sure that all bits are unlocked.. */
> - writew(0x00, uap->port.membase + REG_ICR);
> + pl011_writew(uap, 0x00, REG_ICR);
>
> /*
> * WA: introduce 26ns(1 uart clk) delay before W1C;
> * single apb access will incur 2 pclk(133.12Mhz) delay,
> * so add 2 dummy reads
> */
> - dummy_read = readw(uap->port.membase + REG_ICR);
> - dummy_read = readw(uap->port.membase + REG_ICR);
> + dummy_read = pl011_readw(uap, REG_ICR);
> + dummy_read = pl011_readw(uap, REG_ICR);
> }
>
> static irqreturn_t pl011_int(int irq, void *dev_id)
> @@ -1381,15 +1401,13 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
> int handled = 0;
>
> spin_lock_irqsave(&uap->port.lock, flags);
> - imsc = readw(uap->port.membase + REG_IMSC);
> - status = readw(uap->port.membase + REG_RIS) & imsc;
> + imsc = pl011_readw(uap, REG_IMSC);
> + status = pl011_readw(uap, REG_RIS) & imsc;
> if (status) {
> do {
> check_apply_cts_event_workaround(uap);
> -
> - writew(status & ~(UART011_TXIS|UART011_RTIS|
> - UART011_RXIS),
> - uap->port.membase + REG_ICR);
> + pl011_writew(uap, status & ~(UART011_TXIS|UART011_RTIS|
> + UART011_RXIS), REG_ICR);
>
> if (status & (UART011_RTIS|UART011_RXIS)) {
> if (pl011_dma_rx_running(uap))
> @@ -1406,7 +1424,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
> if (pass_counter-- == 0)
> break;
>
> - status = readw(uap->port.membase + REG_RIS) & imsc;
> + status = pl011_readw(uap, REG_RIS) & imsc;
> } while (status != 0);
> handled = 1;
> }
> @@ -1420,7 +1438,7 @@ 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 = readw(uap->port.membase + REG_FR);
> + unsigned int status = pl011_readw(uap, REG_FR);
> return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT;
> }
>
> @@ -1429,7 +1447,7 @@ static unsigned int pl011_get_mctrl(struct uart_port *port)
> struct uart_amba_port *uap =
> container_of(port, struct uart_amba_port, port);
> unsigned int result = 0;
> - unsigned int status = readw(uap->port.membase + REG_FR);
> + unsigned int status = pl011_readw(uap, REG_FR);
>
> #define TIOCMBIT(uartbit, tiocmbit) \
> if (status & uartbit) \
> @@ -1449,7 +1467,7 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
> container_of(port, struct uart_amba_port, port);
> unsigned int cr;
>
> - cr = readw(uap->port.membase + REG_CR);
> + cr = pl011_readw(uap, REG_CR);
>
> #define TIOCMBIT(tiocmbit, uartbit) \
> if (mctrl & tiocmbit) \
> @@ -1469,7 +1487,7 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
> }
> #undef TIOCMBIT
>
> - writew(cr, uap->port.membase + REG_CR);
> + pl011_writew(uap, cr, REG_CR);
> }
>
> static void pl011_break_ctl(struct uart_port *port, int break_state)
> @@ -1480,12 +1498,12 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
> unsigned int lcr_h;
>
> spin_lock_irqsave(&uap->port.lock, flags);
> - lcr_h = readw(uap->port.membase + uap->lcrh_tx);
> + lcr_h = pl011_readw(uap, uap->lcrh_tx);
> if (break_state == -1)
> lcr_h |= UART01x_LCRH_BRK;
> else
> lcr_h &= ~UART01x_LCRH_BRK;
> - writew(lcr_h, uap->port.membase + uap->lcrh_tx);
> + pl011_writew(uap, lcr_h, uap->lcrh_tx);
> spin_unlock_irqrestore(&uap->port.lock, flags);
> }
>
> @@ -1495,9 +1513,8 @@ static void pl011_quiesce_irqs(struct uart_port *port)
> {
> struct uart_amba_port *uap =
> container_of(port, struct uart_amba_port, port);
> - unsigned char __iomem *regs = uap->port.membase;
>
> - writew(readw(regs + REG_MIS), regs + REG_ICR);
> + pl011_writew(uap, pl011_readw(uap, REG_MIS), REG_ICR);
> /*
> * There is no way to clear TXIM as this is "ready to transmit IRQ", so
> * we simply mask it. start_tx() will unmask it.
> @@ -1511,7 +1528,7 @@ static void pl011_quiesce_irqs(struct uart_port *port)
> * (including tx queue), so we're also fine with start_tx()'s caller
> * side.
> */
> - writew(readw(regs + REG_IMSC) & ~UART011_TXIM, regs + REG_IMSC);
> + pl011_writew(uap, pl011_readw(uap, REG_IMSC) & ~UART011_TXIM, REG_IMSC);
> }
>
> static int pl011_get_poll_char(struct uart_port *port)
> @@ -1526,11 +1543,11 @@ static int pl011_get_poll_char(struct uart_port *port)
> */
> pl011_quiesce_irqs(port);
>
> - status = readw(uap->port.membase + REG_FR);
> + status = pl011_readw(uap, REG_FR);
> if (status & UART01x_FR_RXFE)
> return NO_POLL_CHAR;
>
> - return readw(uap->port.membase + REG_DR);
> + return pl011_readw(uap, REG_DR);
> }
>
> static void pl011_put_poll_char(struct uart_port *port,
> @@ -1539,10 +1556,10 @@ static void pl011_put_poll_char(struct uart_port *port,
> struct uart_amba_port *uap =
> container_of(port, struct uart_amba_port, port);
>
> - while (readw(uap->port.membase + REG_FR) & UART01x_FR_TXFF)
> + while (pl011_readw(uap, REG_FR) & UART01x_FR_TXFF)
> barrier();
>
> - writew(ch, uap->port.membase + REG_DR);
> + pl011_writew(uap, ch, REG_DR);
> }
>
> #endif /* CONFIG_CONSOLE_POLL */
> @@ -1566,15 +1583,15 @@ static int pl011_hwinit(struct uart_port *port)
> uap->port.uartclk = clk_get_rate(uap->clk);
>
> /* Clear pending error and receive interrupts */
> - writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS |
> - UART011_RTIS | UART011_RXIS, uap->port.membase + REG_ICR);
> + pl011_writew(uap, UART011_OEIS | UART011_BEIS | UART011_PEIS |
> + UART011_FEIS | UART011_RTIS | UART011_RXIS, REG_ICR);
>
> /*
> * Save interrupts enable mask, and enable RX interrupts in case if
> * the interrupt is used for NMI entry.
> */
> - uap->im = readw(uap->port.membase + REG_IMSC);
> - writew(UART011_RTIM | UART011_RXIM, uap->port.membase + REG_IMSC);
> + uap->im = pl011_readw(uap, REG_IMSC);
> + pl011_writew(uap, UART011_RTIM | UART011_RXIM, REG_IMSC);
>
> if (dev_get_platdata(uap->port.dev)) {
> struct amba_pl011_data *plat;
> @@ -1588,7 +1605,7 @@ static int pl011_hwinit(struct uart_port *port)
>
> static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
> {
> - writew(lcr_h, uap->port.membase + uap->lcrh_rx);
> + pl011_writew(uap, lcr_h, uap->lcrh_rx);
> if (uap->lcrh_rx != uap->lcrh_tx) {
> int i;
> /*
> @@ -1596,14 +1613,14 @@ static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
> * to get this delay write read only register 10 times
> */
> for (i = 0; i < 10; ++i)
> - writew(0xff, uap->port.membase + REG_MIS);
> - writew(lcr_h, uap->port.membase + uap->lcrh_tx);
> + pl011_writew(uap, 0xff, REG_MIS);
> + pl011_writew(uap, lcr_h, uap->lcrh_tx);
> }
> }
>
> static int pl011_allocate_irq(struct uart_amba_port *uap)
> {
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
>
> return request_irq(uap->port.irq, pl011_int, 0, "uart-pl011", uap);
> }
> @@ -1618,12 +1635,11 @@ static void pl011_enable_interrupts(struct uart_amba_port *uap)
> spin_lock_irq(&uap->port.lock);
>
> /* Clear out any spuriously appearing RX interrupts */
> - writew(UART011_RTIS | UART011_RXIS,
> - uap->port.membase + REG_ICR);
> + pl011_writew(uap, UART011_RTIS | UART011_RXIS, REG_ICR);
> uap->im = UART011_RTIM;
> if (!pl011_dma_rx_running(uap))
> uap->im |= UART011_RXIM;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> + pl011_writew(uap, uap->im, REG_IMSC);
> spin_unlock_irq(&uap->port.lock);
> }
>
> @@ -1642,21 +1658,21 @@ static int pl011_startup(struct uart_port *port)
> if (retval)
> goto clk_dis;
>
> - writew(uap->vendor->ifls, uap->port.membase + REG_IFLS);
> + pl011_writew(uap, uap->vendor->ifls, REG_IFLS);
>
> spin_lock_irq(&uap->port.lock);
>
> /* restore RTS and DTR */
> cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR);
> cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
> - writew(cr, uap->port.membase + REG_CR);
> + pl011_writew(uap, cr, REG_CR);
>
> spin_unlock_irq(&uap->port.lock);
>
> /*
> * initialise the old status of the modem signals
> */
> - uap->old_status = readw(uap->port.membase + REG_FR) &
> + uap->old_status = pl011_readw(uap, REG_FR) &
> UART01x_FR_MODEM_ANY;
>
> /* Startup DMA */
> @@ -1696,11 +1712,11 @@ static int sbsa_uart_startup(struct uart_port *port)
> static void pl011_shutdown_channel(struct uart_amba_port *uap,
> unsigned int lcrh)
> {
> - unsigned long val;
> + unsigned long val;
>
> - val = readw(uap->port.membase + lcrh);
> - val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
> - writew(val, uap->port.membase + lcrh);
> + val = pl011_readw(uap, lcrh);
> + val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
> + pl011_writew(uap, val, lcrh);
> }
>
> /*
> @@ -1714,11 +1730,11 @@ static void pl011_disable_uart(struct uart_amba_port *uap)
>
> uap->autorts = false;
> spin_lock_irq(&uap->port.lock);
> - cr = readw(uap->port.membase + REG_CR);
> + cr = pl011_readw(uap, REG_CR);
> uap->old_cr = cr;
> cr &= UART011_CR_RTS | UART011_CR_DTR;
> cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
> - writew(cr, uap->port.membase + REG_CR);
> + pl011_writew(uap, cr, REG_CR);
> spin_unlock_irq(&uap->port.lock);
>
> /*
> @@ -1735,8 +1751,8 @@ static void pl011_disable_interrupts(struct uart_amba_port *uap)
>
> /* mask all interrupts and clear all pending ones */
> uap->im = 0;
> - writew(uap->im, uap->port.membase + REG_IMSC);
> - writew(0xffff, uap->port.membase + REG_ICR);
> + pl011_writew(uap, uap->im, REG_IMSC);
> + pl011_writew(0xffff, REG_ICR);
>
> spin_unlock_irq(&uap->port.lock);
> }
> @@ -1888,8 +1904,8 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
> pl011_enable_ms(port);
>
> /* first, disable everything */
> - old_cr = readw(port->membase + REG_CR);
> - writew(0, port->membase + REG_CR);
> + old_cr = pl011_readw(uap, REG_CR);
> + pl011_writew(uap, 0, REG_CR);
>
> if (termios->c_cflag & CRTSCTS) {
> if (old_cr & UART011_CR_RTS)
> @@ -1922,8 +1938,8 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
> quot -= 2;
> }
> /* Set baud rate */
> - writew(quot & 0x3f, port->membase + REG_FBRD);
> - writew(quot >> 6, port->membase + REG_IBRD);
> + pl011_writew(uap, quot & 0x3f, REG_FBRD);
> + pl011_writew(uap, quot >> 6, REG_IBRD);
>
> /*
> * ----------v----------v----------v----------v-----
> @@ -1932,7 +1948,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
> * ----------^----------^----------^----------^-----
> */
> pl011_write_lcr_h(uap, lcr_h);
> - writew(old_cr, port->membase + REG_CR);
> + pl011_writew(uap, old_cr, REG_CR);
>
> spin_unlock_irqrestore(&port->lock, flags);
> }
> @@ -2073,9 +2089,9 @@ static void pl011_console_putchar(struct uart_port *port, int ch)
> struct uart_amba_port *uap =
> container_of(port, struct uart_amba_port, port);
>
> - while (readw(uap->port.membase + REG_FR) & UART01x_FR_TXFF)
> + while (pl011_readw(uap, REG_FR) & UART01x_FR_TXFF)
> barrier();
> - writew(ch, uap->port.membase + REG_DR);
> + pl011_writew(uap, ch, REG_DR);
> }
>
> static void
> @@ -2100,10 +2116,10 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
> * First save the CR then disable the interrupts
> */
> if (!uap->vendor->always_enabled) {
> - old_cr = readw(uap->port.membase + REG_CR);
> + old_cr = pl011_readw(uap, REG_CR);
> new_cr = old_cr & ~UART011_CR_CTSEN;
> new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
> - writew(new_cr, uap->port.membase + REG_CR);
> + pl011_writew(uap, new_cr, REG_CR);
> }
>
> uart_console_write(&uap->port, s, count, pl011_console_putchar);
> @@ -2113,10 +2129,10 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
> * and restore the TCR
> */
> do {
> - status = readw(uap->port.membase + REG_FR);
> + status = pl011_readw(uap, REG_FR);
> } while (status & UART01x_FR_BUSY);
> if (!uap->vendor->always_enabled)
> - writew(old_cr, uap->port.membase + REG_CR);
> + pl011_writew(uap, old_cr, REG_CR);
>
> if (locked)
> spin_unlock(&uap->port.lock);
> @@ -2129,10 +2145,10 @@ static void __init
> pl011_console_get_options(struct uart_amba_port *uap, int *baud,
> int *parity, int *bits)
> {
> - if (readw(uap->port.membase + REG_CR) & UART01x_CR_UARTEN) {
> + if (pl011_readw(uap, REG_CR) & UART01x_CR_UARTEN) {
> unsigned int lcr_h, ibrd, fbrd;
>
> - lcr_h = readw(uap->port.membase + uap->lcrh_tx);
> + lcr_h = pl011_readw(uap, uap->lcrh_tx);
>
> *parity = 'n';
> if (lcr_h & UART01x_LCRH_PEN) {
> @@ -2147,13 +2163,13 @@ pl011_console_get_options(struct uart_amba_port *uap, int *baud,
> else
> *bits = 8;
>
> - ibrd = readw(uap->port.membase + REG_IBRD);
> - fbrd = readw(uap->port.membase + REG_FBRD);
> + ibrd = pl011_readw(uap, REG_IBRD);
> + fbrd = pl011_readw(uap, REG_FBRD);
>
> *baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd);
>
> if (uap->vendor->oversampling) {
> - if (readw(uap->port.membase + REG_CR)
> + if (pl011_readw(uap, REG_CR)
> & ST_UART011_CR_OVSFACT)
> *baud *= 2;
> }
> @@ -2225,10 +2241,13 @@ static struct console amba_console = {
>
> static void pl011_putc(struct uart_port *port, int c)
> {
> - while (readl(port->membase + REG_FR) & UART01x_FR_TXFF)
> + struct uart_amba_port *uap =
> + container_of(port, struct uart_amba_port, port);
> +
> + while (pl011_readw(uap, REG_FR) & UART01x_FR_TXFF)
> ;
> - writeb(c, port->membase + REG_DR);
> - while (readl(port->membase + REG_FR) & UART01x_FR_BUSY)
> + pl011_writeb(uap, c, REG_DR);
> + while (pl011_readw(uap, REG_FR) & UART01x_FR_BUSY)
> ;
> }
Just for the records, as this has been discussed before: pl011_putc() is
called by the earlycon code, before the uart_port is actually
initialized. So we cannot rely on the accessors, but have to use the
old-fashioned director accessors for this.
Which means you cannot use that approach to get earlycon support for the
ZTE UART, if I get this correctly. It shouldn't be to hard to introduce
another earlycon type specificly for that one, copying pl011_early_write
and pl011_early_console_setup and changing pl011_putc into
zte_uart_putc. But of course this belongs into the final patch (or a
separate one), not in this. So I guess you just leave that function
unchanged in this patch.
As a side note: I wonder why those accessors here are actually 32-bit
wide here, and the data register 8-bits only?
This is in contrast to the rest of the driver, which uses 16-bit
accesses all of the time (in line with the spec).
Cheers,
Andre.
>
> @@ -2355,8 +2374,8 @@ static int pl011_register_port(struct uart_amba_port *uap)
> int ret;
>
> /* Ensure interrupts from this UART are masked and cleared */
> - writew(0, uap->port.membase + REG_IMSC);
> - writew(0xffff, uap->port.membase + REG_ICR);
> + pl011_writew(uap, 0, REG_IMSC);
> + pl011_writew(uap, 0xffff, REG_ICR);
>
> if (!amba_reg.state) {
> ret = uart_register_driver(&amba_reg);
> --
> 1.9.1
>
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