Hi,
On 20. 11. 22, 9:21, Jisheng Zhang wrote:
Add the driver for Bouffalolab UART IP which is found in Bouffalolab
SoCs such as bl808.
UART driver probe will create path named "/dev/ttySx".
Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
...
> #define UART_FIFO_CONFIG_0 (0x80)
Superfluous parentheses.
...
+static void bflb_uart_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ const struct ktermios *old)
+{
+ unsigned long flags;
+ u32 valt, valr, val;
+ unsigned int baud, min;
+
+ valt = valr = 0;
Unneeded (see below).
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /* set data length */
+ val = tty_get_char_size(termios->c_cflag) - 1;
+ valt |= (val << UART_CR_UTX_BIT_CNT_D_SFT);
Use =, not |=. Other than that, can FIELD_SET() be used, provided you
already define the constants using GENMASK()?
+
+ /* calculate parity */
+ termios->c_cflag &= ~CMSPAR; /* no support mark/space */
+ if (termios->c_cflag & PARENB) {
+ valt |= UART_CR_UTX_PRT_EN;
+ if (termios->c_cflag & PARODD)
+ valr |= UART_CR_UTX_PRT_SEL;
This should be valt, IMO.
+ }
+
+ valr = valt;
If not, this doesn't make sense to me.
+ /* calculate stop bits */
+ if (termios->c_cflag & CSTOPB)
+ val = 2;
+ else
+ val = 1;
+ valt |= (val << UART_CR_UTX_BIT_CNT_P_SFT);
+
+ /* flow control */
+ if (termios->c_cflag & CRTSCTS)
+ valt |= UART_CR_UTX_CTS_EN;
+
+ /* enable TX freerunning mode */
+ valt |= UART_CR_UTX_FRM_EN;
+
+ valt |= UART_CR_UTX_EN;
+ valr |= UART_CR_URX_EN;
Why this is not the very first and only for valt and copied to valr above?
+
+ wrl(port, UART_UTX_CONFIG, valt);
+ wrl(port, UART_URX_CONFIG, valr);
+
+ min = port->uartclk / (UART_CR_UTX_BIT_PRD + 1);
+ baud = uart_get_baud_rate(port, termios, old, min, 4000000);
+
+ val = DIV_ROUND_CLOSEST(port->uartclk, baud) - 1;
+ val &= UART_CR_UTX_BIT_PRD;
+ val |= (val << 16);
+ wrl(port, UART_BIT_PRD, val);
+
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void bflb_uart_rx_chars(struct uart_port *port)
+{
+ unsigned char ch, flag;
Please use u8. (serial_core should too, but that's only on a TODO list yet)
+ unsigned long status;
Long? I think u32.
+
+ while ((status = rdl(port, UART_FIFO_CONFIG_1)) & UART_RX_FIFO_CNT_MSK) {
+ ch = rdl(port, UART_FIFO_RDATA) & UART_FIFO_RDATA_MSK;
+ flag = TTY_NORMAL;
Drop this flag completely and use the constant below directly.
+ port->icount.rx++;
+
+ if (uart_handle_sysrq_char(port, ch))
+ continue;
+ uart_insert_char(port, 0, 0, ch, flag);
+ }
+
+ spin_unlock(&port->lock);
+ tty_flip_buffer_push(&port->state->port);
+ spin_lock(&port->lock);
+}
+
+static void bflb_uart_tx_chars(struct uart_port *port)
+{
Are you unable to use the TX helper? If so:
* why?
* use uart_advance_xmit() at least.
+ struct circ_buf *xmit = &port->state->xmit;
+ unsigned int pending, count;
+
+ if (port->x_char) {
+ /* Send special char - probably flow control */
+ wrl(port, UART_FIFO_WDATA, port->x_char);
+ port->x_char = 0;
+ port->icount.tx++;
+ return;
+ }
+
+ pending = uart_circ_chars_pending(xmit);
+ if (pending > 0) {
+ count = (rdl(port, UART_FIFO_CONFIG_1) &
+ UART_TX_FIFO_CNT_MSK) >> UART_TX_FIFO_CNT_SFT;
+ if (count > pending)
+ count = pending;
+ if (count > 0) {
+ pending -= count;
+ while (count--) {
+ wrl(port, UART_FIFO_WDATA, xmit->buf[xmit->tail]);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ }
+ if (pending < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+ }
+ }
+
+ if (pending == 0)
+ bflb_uart_stop_tx(port);
+}
+
+static irqreturn_t bflb_uart_interrupt(int irq, void *data)
+{
+ struct uart_port *port = data;
+ u32 isr, val;
+
+ isr = rdl(port, UART_INT_STS);
+ wrl(port, UART_INT_CLEAR, isr);
+
+ isr &= ~rdl(port, UART_INT_MASK);
+
+ spin_lock(&port->lock);
+
+ if (isr & UART_URX_FER_INT) {
+ /* RX FIFO error interrupt */
+ val = rdl(port, UART_FIFO_CONFIG_0);
+ if (val & UART_RX_FIFO_OVERFLOW)
+ port->icount.overrun++;
+
+ val |= UART_RX_FIFO_CLR;
+ wrl(port, UART_FIFO_CONFIG_0, val);
+ }
+
+ if (isr & (UART_URX_FIFO_INT | UART_URX_RTO_INT)) {
+ bflb_uart_rx_chars(port);
+ }
+ if (isr & (UART_UTX_FIFO_INT | UART_UTX_END_INT)) {
+ bflb_uart_tx_chars(port);
+ }
Superfluous braces.
+
+ spin_unlock(&port->lock);
+
+ return IRQ_RETVAL(isr);
Can it happen that UART_INT_STS is nonzero and UART_INT_MASK is zero?
You'd cause "irqX: nobody cared" in that case.
+}
+
+static void bflb_uart_config_port(struct uart_port *port, int flags)
+{
+ u32 val;
+
+ port->type = PORT_BFLB;
+
+ /* Clear mask, so no surprise interrupts. */
surprising?
+ val = rdl(port, UART_INT_MASK);
+ val |= UART_UTX_END_INT;
+ val |= UART_UTX_FIFO_INT;
+ val |= UART_URX_FIFO_INT;
+ val |= UART_URX_RTO_INT;
+ val |= UART_URX_FER_INT;
+ wrl(port, UART_INT_MASK, val);
+}
+
+static int bflb_uart_startup(struct uart_port *port)
+{
+ unsigned long flags;
+ int ret;
+ u32 val;
+
+ ret = devm_request_irq(port->dev, port->irq, bflb_uart_interrupt,
+ IRQF_SHARED, port->name, port);
+ if (ret) {
+ dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
+ port->irq, ret);
+ return ret;
+ }
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ val = rdl(port, UART_INT_MASK);
+ val |= 0xfff;
Can this be a defined macro too, please?
+ wrl(port, UART_INT_MASK, val);
+
+ wrl(port, UART_DATA_CONFIG, 0);
+ wrl(port, UART_SW_MODE, 0);
+ wrl(port, UART_URX_RTO_TIMER, 0x4f);
Another magic constant.
+
+ val = rdl(port, UART_FIFO_CONFIG_1);
+ val &= ~UART_RX_FIFO_TH_MSK;
+ val |= BFLB_UART_RX_FIFO_TH << UART_RX_FIFO_TH_SFT;
FIELD_SET()?
+ wrl(port, UART_FIFO_CONFIG_1, val);
+
+ /* Unmask RX interrupts now */
+ val = rdl(port, UART_INT_MASK);
+ val &= ~UART_URX_FIFO_INT;
+ val &= ~UART_URX_RTO_INT;
+ val &= ~UART_URX_FER_INT;
+ wrl(port, UART_INT_MASK, val);
+ val = rdl(port, UART_UTX_CONFIG);
+ val |= UART_CR_UTX_EN;
+ wrl(port, UART_UTX_CONFIG, val);
+ val = rdl(port, UART_URX_CONFIG);
+ val |= UART_CR_URX_EN;
+ wrl(port, UART_URX_CONFIG, val);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return 0;
+}
...
+/*
+ * Interrupts are disabled on entering
+ */
+static void bflb_uart_console_write(struct console *co, const char *s,
+ u_int count)
+{
+ struct uart_port *port = &bflb_uart_ports[co->index]->port;
+ u32 status, reg, mask;
+
+ /* save then disable interrupts */
+ mask = rdl(port, UART_INT_MASK);
+ reg = -1;
You use 0xfff earlier, now 0xffffffff. Is that OK? Why not use the same
constant?
+ wrl(port, UART_INT_MASK, reg);
+
+ /* Make sure that tx is enabled */
+ reg = rdl(port, UART_UTX_CONFIG);
+ reg |= UART_CR_UTX_EN;
+ wrl(port, UART_UTX_CONFIG, reg);
+
+ uart_console_write(port, s, count, bflb_console_putchar);
+
+ /* wait for TX done */
+ do {
+ status = rdl(port, UART_STATUS);
+ } while ((status & UART_STS_UTX_BUS_BUSY));
+
+ /* restore IRQ mask */
+ wrl(port, UART_INT_MASK, mask);
+}
regards,
--
js
suse labs
