diff options
Diffstat (limited to 'drivers/tty/serial/stm32-usart.c')
-rw-r--r-- | drivers/tty/serial/stm32-usart.c | 348 |
1 files changed, 249 insertions, 99 deletions
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index e8d7a7bb4339..24a2261f879a 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -105,9 +105,7 @@ static int stm32_config_rs485(struct uart_port *port, struct stm32_usart_config *cfg = &stm32_port->info->cfg; u32 usartdiv, baud, cr1, cr3; bool over8; - unsigned long flags; - spin_lock_irqsave(&port->lock, flags); stm32_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); port->rs485 = *rs485conf; @@ -147,7 +145,6 @@ static int stm32_config_rs485(struct uart_port *port, } stm32_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); - spin_unlock_irqrestore(&port->lock, flags); return 0; } @@ -194,8 +191,8 @@ static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res, return 0; } -static unsigned long -stm32_get_char(struct uart_port *port, u32 *sr, int *last_res) +static unsigned long stm32_get_char(struct uart_port *port, u32 *sr, + int *last_res) { struct stm32_port *stm32_port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; @@ -205,10 +202,13 @@ stm32_get_char(struct uart_port *port, u32 *sr, int *last_res) c = stm32_port->rx_buf[RX_BUF_L - (*last_res)--]; if ((*last_res) == 0) *last_res = RX_BUF_L; - return c; } else { - return readl_relaxed(port->membase + ofs->rdr); + c = readl_relaxed(port->membase + ofs->rdr); + /* apply RDR data mask */ + c &= stm32_port->rdr_mask; } + + return c; } static void stm32_receive_chars(struct uart_port *port, bool threaded) @@ -225,35 +225,51 @@ static void stm32_receive_chars(struct uart_port *port, bool threaded) while (stm32_pending_rx(port, &sr, &stm32_port->last_res, threaded)) { sr |= USART_SR_DUMMY_RX; - c = stm32_get_char(port, &sr, &stm32_port->last_res); flag = TTY_NORMAL; - port->icount.rx++; + /* + * Status bits has to be cleared before reading the RDR: + * In FIFO mode, reading the RDR will pop the next data + * (if any) along with its status bits into the SR. + * Not doing so leads to misalignement between RDR and SR, + * and clear status bits of the next rx data. + * + * Clear errors flags for stm32f7 and stm32h7 compatible + * devices. On stm32f4 compatible devices, the error bit is + * cleared by the sequence [read SR - read DR]. + */ + if ((sr & USART_SR_ERR_MASK) && ofs->icr != UNDEF_REG) + stm32_clr_bits(port, ofs->icr, USART_ICR_ORECF | + USART_ICR_PECF | USART_ICR_FECF); + + c = stm32_get_char(port, &sr, &stm32_port->last_res); + port->icount.rx++; if (sr & USART_SR_ERR_MASK) { - if (sr & USART_SR_LBD) { - port->icount.brk++; - if (uart_handle_break(port)) - continue; - } else if (sr & USART_SR_ORE) { - if (ofs->icr != UNDEF_REG) - writel_relaxed(USART_ICR_ORECF, - port->membase + - ofs->icr); + if (sr & USART_SR_ORE) { port->icount.overrun++; } else if (sr & USART_SR_PE) { port->icount.parity++; } else if (sr & USART_SR_FE) { - port->icount.frame++; + /* Break detection if character is null */ + if (!c) { + port->icount.brk++; + if (uart_handle_break(port)) + continue; + } else { + port->icount.frame++; + } } sr &= port->read_status_mask; - if (sr & USART_SR_LBD) - flag = TTY_BREAK; - else if (sr & USART_SR_PE) + if (sr & USART_SR_PE) { flag = TTY_PARITY; - else if (sr & USART_SR_FE) - flag = TTY_FRAME; + } else if (sr & USART_SR_FE) { + if (!c) + flag = TTY_BREAK; + else + flag = TTY_FRAME; + } } if (uart_handle_sysrq_char(port, c)) @@ -271,21 +287,6 @@ static void stm32_tx_dma_complete(void *arg) struct uart_port *port = arg; struct stm32_port *stm32port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32port->info->ofs; - unsigned int isr; - int ret; - - ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, - isr, - (isr & USART_SR_TC), - 10, 100000); - - if (ret) - dev_err(port->dev, "terminal count not set\n"); - - if (ofs->icr == UNDEF_REG) - stm32_clr_bits(port, ofs->isr, USART_SR_TC); - else - stm32_set_bits(port, ofs->icr, USART_CR_TC); stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT); stm32port->tx_dma_busy = false; @@ -294,32 +295,57 @@ static void stm32_tx_dma_complete(void *arg) stm32_transmit_chars(port); } +static void stm32_tx_interrupt_enable(struct uart_port *port) +{ + struct stm32_port *stm32_port = to_stm32_port(port); + struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + + /* + * Enables TX FIFO threashold irq when FIFO is enabled, + * or TX empty irq when FIFO is disabled + */ + if (stm32_port->fifoen) + stm32_set_bits(port, ofs->cr3, USART_CR3_TXFTIE); + else + stm32_set_bits(port, ofs->cr1, USART_CR1_TXEIE); +} + +static void stm32_tx_interrupt_disable(struct uart_port *port) +{ + struct stm32_port *stm32_port = to_stm32_port(port); + struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + + if (stm32_port->fifoen) + stm32_clr_bits(port, ofs->cr3, USART_CR3_TXFTIE); + else + stm32_clr_bits(port, ofs->cr1, USART_CR1_TXEIE); +} + static void stm32_transmit_chars_pio(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct circ_buf *xmit = &port->state->xmit; - unsigned int isr; - int ret; if (stm32_port->tx_dma_busy) { stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT); stm32_port->tx_dma_busy = false; } - ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, - isr, - (isr & USART_SR_TXE), - 10, 100000); - - if (ret) - dev_err(port->dev, "tx empty not set\n"); - - stm32_set_bits(port, ofs->cr1, USART_CR1_TXEIE); + while (!uart_circ_empty(xmit)) { + /* Check that TDR is empty before filling FIFO */ + if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE)) + break; + writel_relaxed(xmit->buf[xmit->tail], port->membase + ofs->tdr); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + } - writel_relaxed(xmit->buf[xmit->tail], port->membase + ofs->tdr); - xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); - port->icount.tx++; + /* rely on TXE irq (mask or unmask) for sending remaining data */ + if (uart_circ_empty(xmit)) + stm32_tx_interrupt_disable(port); + else + stm32_tx_interrupt_enable(port); } static void stm32_transmit_chars_dma(struct uart_port *port) @@ -377,7 +403,6 @@ static void stm32_transmit_chars_dma(struct uart_port *port) /* Issue pending DMA TX requests */ dma_async_issue_pending(stm32port->tx_ch); - stm32_clr_bits(port, ofs->isr, USART_SR_TC); stm32_set_bits(port, ofs->cr3, USART_CR3_DMAT); xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); @@ -401,15 +426,15 @@ static void stm32_transmit_chars(struct uart_port *port) return; } - if (uart_tx_stopped(port)) { - stm32_stop_tx(port); + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + stm32_tx_interrupt_disable(port); return; } - if (uart_circ_empty(xmit)) { - stm32_stop_tx(port); - return; - } + if (ofs->icr == UNDEF_REG) + stm32_clr_bits(port, ofs->isr, USART_SR_TC); + else + stm32_set_bits(port, ofs->icr, USART_ICR_TCCF); if (stm32_port->tx_ch) stm32_transmit_chars_dma(port); @@ -420,7 +445,7 @@ static void stm32_transmit_chars(struct uart_port *port) uart_write_wakeup(port); if (uart_circ_empty(xmit)) - stm32_stop_tx(port); + stm32_tx_interrupt_disable(port); } static irqreturn_t stm32_interrupt(int irq, void *ptr) @@ -434,6 +459,10 @@ static irqreturn_t stm32_interrupt(int irq, void *ptr) sr = readl_relaxed(port->membase + ofs->isr); + if ((sr & USART_SR_RTOF) && ofs->icr != UNDEF_REG) + writel_relaxed(USART_ICR_RTOCF, + port->membase + ofs->icr); + if ((sr & USART_SR_WUF) && (ofs->icr != UNDEF_REG)) writel_relaxed(USART_ICR_WUCF, port->membase + ofs->icr); @@ -495,10 +524,7 @@ static unsigned int stm32_get_mctrl(struct uart_port *port) /* Transmit stop */ static void stm32_stop_tx(struct uart_port *port) { - struct stm32_port *stm32_port = to_stm32_port(port); - struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; - - stm32_clr_bits(port, ofs->cr1, USART_CR1_TXEIE); + stm32_tx_interrupt_disable(port); } /* There are probably characters waiting to be transmitted. */ @@ -520,7 +546,10 @@ static void stm32_throttle(struct uart_port *port) unsigned long flags; spin_lock_irqsave(&port->lock, flags); - stm32_clr_bits(port, ofs->cr1, USART_CR1_RXNEIE); + stm32_clr_bits(port, ofs->cr1, stm32_port->cr1_irq); + if (stm32_port->cr3_irq) + stm32_clr_bits(port, ofs->cr3, stm32_port->cr3_irq); + spin_unlock_irqrestore(&port->lock, flags); } @@ -532,7 +561,10 @@ static void stm32_unthrottle(struct uart_port *port) unsigned long flags; spin_lock_irqsave(&port->lock, flags); - stm32_set_bits(port, ofs->cr1, USART_CR1_RXNEIE); + stm32_set_bits(port, ofs->cr1, stm32_port->cr1_irq); + if (stm32_port->cr3_irq) + stm32_set_bits(port, ofs->cr3, stm32_port->cr3_irq); + spin_unlock_irqrestore(&port->lock, flags); } @@ -542,7 +574,10 @@ static void stm32_stop_rx(struct uart_port *port) struct stm32_port *stm32_port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; - stm32_clr_bits(port, ofs->cr1, USART_CR1_RXNEIE); + stm32_clr_bits(port, ofs->cr1, stm32_port->cr1_irq); + if (stm32_port->cr3_irq) + stm32_clr_bits(port, ofs->cr3, stm32_port->cr3_irq); + } /* Handle breaks - ignored by us */ @@ -554,7 +589,6 @@ static int stm32_startup(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; - struct stm32_usart_config *cfg = &stm32_port->info->cfg; const char *name = to_platform_device(port->dev)->name; u32 val; int ret; @@ -565,16 +599,21 @@ static int stm32_startup(struct uart_port *port) if (ret) return ret; - if (cfg->has_wakeup && stm32_port->wakeirq >= 0) { - ret = dev_pm_set_dedicated_wake_irq(port->dev, - stm32_port->wakeirq); - if (ret) { - free_irq(port->irq, port); - return ret; - } + /* RX FIFO Flush */ + if (ofs->rqr != UNDEF_REG) + stm32_set_bits(port, ofs->rqr, USART_RQR_RXFRQ); + + /* Tx and RX FIFO configuration */ + if (stm32_port->fifoen) { + val = readl_relaxed(port->membase + ofs->cr3); + val &= ~(USART_CR3_TXFTCFG_MASK | USART_CR3_RXFTCFG_MASK); + val |= USART_CR3_TXFTCFG_HALF << USART_CR3_TXFTCFG_SHIFT; + val |= USART_CR3_RXFTCFG_HALF << USART_CR3_RXFTCFG_SHIFT; + writel_relaxed(val, port->membase + ofs->cr3); } - val = USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE; + /* RX FIFO enabling */ + val = stm32_port->cr1_irq | USART_CR1_RE; if (stm32_port->fifoen) val |= USART_CR1_FIFOEN; stm32_set_bits(port, ofs->cr1, val); @@ -587,18 +626,57 @@ static void stm32_shutdown(struct uart_port *port) struct stm32_port *stm32_port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct stm32_usart_config *cfg = &stm32_port->info->cfg; - u32 val; + u32 val, isr; + int ret; - val = USART_CR1_TXEIE | USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE; + val = USART_CR1_TXEIE | USART_CR1_TE; + val |= stm32_port->cr1_irq | USART_CR1_RE; val |= BIT(cfg->uart_enable_bit); if (stm32_port->fifoen) val |= USART_CR1_FIFOEN; + + ret = readl_relaxed_poll_timeout(port->membase + ofs->isr, + isr, (isr & USART_SR_TC), + 10, 100000); + + if (ret) + dev_err(port->dev, "transmission complete not set\n"); + stm32_clr_bits(port, ofs->cr1, val); - dev_pm_clear_wake_irq(port->dev); free_irq(port->irq, port); } +static unsigned int stm32_get_databits(struct ktermios *termios) +{ + unsigned int bits; + + tcflag_t cflag = termios->c_cflag; + + switch (cflag & CSIZE) { + /* + * CSIZE settings are not necessarily supported in hardware. + * CSIZE unsupported configurations are handled here to set word length + * to 8 bits word as default configuration and to print debug message. + */ + case CS5: + bits = 5; + break; + case CS6: + bits = 6; + break; + case CS7: + bits = 7; + break; + /* default including CS8 */ + default: + bits = 8; + break; + } + + return bits; +} + static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { @@ -606,7 +684,7 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct stm32_usart_config *cfg = &stm32_port->info->cfg; struct serial_rs485 *rs485conf = &port->rs485; - unsigned int baud; + unsigned int baud, bits; u32 usartdiv, mantissa, fraction, oversampling; tcflag_t cflag = termios->c_cflag; u32 cr1, cr2, cr3; @@ -622,26 +700,64 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, /* Stop serial port and reset value */ writel_relaxed(0, port->membase + ofs->cr1); - cr1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_RXNEIE; + /* flush RX & TX FIFO */ + if (ofs->rqr != UNDEF_REG) + stm32_set_bits(port, ofs->rqr, + USART_RQR_TXFRQ | USART_RQR_RXFRQ); + cr1 = USART_CR1_TE | USART_CR1_RE; if (stm32_port->fifoen) cr1 |= USART_CR1_FIFOEN; cr2 = 0; - cr3 = 0; + cr3 = readl_relaxed(port->membase + ofs->cr3); + cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE + | USART_CR3_TXFTCFG_MASK; if (cflag & CSTOPB) cr2 |= USART_CR2_STOP_2B; + bits = stm32_get_databits(termios); + stm32_port->rdr_mask = (BIT(bits) - 1); + if (cflag & PARENB) { + bits++; cr1 |= USART_CR1_PCE; - if ((cflag & CSIZE) == CS8) { - if (cfg->has_7bits_data) - cr1 |= USART_CR1_M0; - else - cr1 |= USART_CR1_M; - } } + /* + * Word length configuration: + * CS8 + parity, 9 bits word aka [M1:M0] = 0b01 + * CS7 or (CS6 + parity), 7 bits word aka [M1:M0] = 0b10 + * CS8 or (CS7 + parity), 8 bits word aka [M1:M0] = 0b00 + * M0 and M1 already cleared by cr1 initialization. + */ + if (bits == 9) + cr1 |= USART_CR1_M0; + else if ((bits == 7) && cfg->has_7bits_data) + cr1 |= USART_CR1_M1; + else if (bits != 8) + dev_dbg(port->dev, "Unsupported data bits config: %u bits\n" + , bits); + + if (ofs->rtor != UNDEF_REG && (stm32_port->rx_ch || + stm32_port->fifoen)) { + if (cflag & CSTOPB) + bits = bits + 3; /* 1 start bit + 2 stop bits */ + else + bits = bits + 2; /* 1 start bit + 1 stop bit */ + + /* RX timeout irq to occur after last stop bit + bits */ + stm32_port->cr1_irq = USART_CR1_RTOIE; + writel_relaxed(bits, port->membase + ofs->rtor); + cr2 |= USART_CR2_RTOEN; + /* Not using dma, enable fifo threshold irq */ + if (!stm32_port->rx_ch) + stm32_port->cr3_irq = USART_CR3_RXFTIE; + } + + cr1 |= stm32_port->cr1_irq; + cr3 |= stm32_port->cr3_irq; + if (cflag & PARODD) cr1 |= USART_CR1_PS; @@ -679,14 +795,14 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios, if (termios->c_iflag & INPCK) port->read_status_mask |= USART_SR_PE | USART_SR_FE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) - port->read_status_mask |= USART_SR_LBD; + port->read_status_mask |= USART_SR_FE; /* Characters to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask = USART_SR_PE | USART_SR_FE; if (termios->c_iflag & IGNBRK) { - port->ignore_status_mask |= USART_SR_LBD; + port->ignore_status_mask |= USART_SR_FE; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). @@ -808,12 +924,32 @@ static int stm32_init_port(struct stm32_port *stm32port, port->flags = UPF_BOOT_AUTOCONF; port->ops = &stm32_uart_ops; port->dev = &pdev->dev; - port->irq = platform_get_irq(pdev, 0); + port->fifosize = stm32port->info->cfg.fifosize; + + ret = platform_get_irq(pdev, 0); + if (ret <= 0) { + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "Can't get event IRQ: %d\n", ret); + return ret ? ret : -ENODEV; + } + port->irq = ret; + port->rs485_config = stm32_config_rs485; stm32_init_rs485(port, pdev); - stm32port->wakeirq = platform_get_irq(pdev, 1); + if (stm32port->info->cfg.has_wakeup) { + stm32port->wakeirq = platform_get_irq(pdev, 1); + if (stm32port->wakeirq <= 0 && stm32port->wakeirq != -ENXIO) { + if (stm32port->wakeirq != -EPROBE_DEFER) + dev_err(&pdev->dev, + "Can't get event wake IRQ: %d\n", + stm32port->wakeirq); + return stm32port->wakeirq ? stm32port->wakeirq : + -ENODEV; + } + } + stm32port->fifoen = stm32port->info->cfg.has_fifo; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -862,6 +998,8 @@ static struct stm32_port *stm32_of_get_stm32_port(struct platform_device *pdev) stm32_ports[id].hw_flow_control = of_property_read_bool(np, "st,hw-flow-ctrl"); stm32_ports[id].port.line = id; + stm32_ports[id].cr1_irq = USART_CR1_RXNEIE; + stm32_ports[id].cr3_irq = 0; stm32_ports[id].last_res = RX_BUF_L; return &stm32_ports[id]; } @@ -1020,15 +1158,22 @@ static int stm32_serial_probe(struct platform_device *pdev) if (ret) return ret; - if (stm32port->info->cfg.has_wakeup && stm32port->wakeirq >= 0) { + if (stm32port->wakeirq > 0) { ret = device_init_wakeup(&pdev->dev, true); if (ret) goto err_uninit; + + ret = dev_pm_set_dedicated_wake_irq(&pdev->dev, + stm32port->wakeirq); + if (ret) + goto err_nowup; + + device_set_wakeup_enable(&pdev->dev, false); } ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port); if (ret) - goto err_nowup; + goto err_wirq; ret = stm32_of_dma_rx_probe(stm32port, pdev); if (ret) @@ -1042,8 +1187,12 @@ static int stm32_serial_probe(struct platform_device *pdev) return 0; +err_wirq: + if (stm32port->wakeirq > 0) + dev_pm_clear_wake_irq(&pdev->dev); + err_nowup: - if (stm32port->info->cfg.has_wakeup && stm32port->wakeirq >= 0) + if (stm32port->wakeirq > 0) device_init_wakeup(&pdev->dev, false); err_uninit: @@ -1057,7 +1206,6 @@ static int stm32_serial_remove(struct platform_device *pdev) struct uart_port *port = platform_get_drvdata(pdev); struct stm32_port *stm32_port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; - struct stm32_usart_config *cfg = &stm32_port->info->cfg; stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAR); @@ -1079,8 +1227,10 @@ static int stm32_serial_remove(struct platform_device *pdev) TX_BUF_L, stm32_port->tx_buf, stm32_port->tx_dma_buf); - if (cfg->has_wakeup && stm32_port->wakeirq >= 0) + if (stm32_port->wakeirq > 0) { + dev_pm_clear_wake_irq(&pdev->dev); device_init_wakeup(&pdev->dev, false); + } clk_disable_unprepare(stm32_port->clk); @@ -1195,7 +1345,7 @@ static void stm32_serial_enable_wakeup(struct uart_port *port, bool enable) struct stm32_usart_config *cfg = &stm32_port->info->cfg; u32 val; - if (!cfg->has_wakeup || stm32_port->wakeirq < 0) + if (stm32_port->wakeirq <= 0) return; if (enable) { |