Hi Miquel,
On ven., oct. 06 2017, Miquel Raynal <miquel.raynal@xxxxxxxxxxxxxxxxxx> wrote:
> While the standard UART port can use a single IRQ that 'sums' both RX
> and TX interrupts, the extended port cannot and has to use two different
> ISR, one for each direction. The standard port also has the hability
ability
> to use two separate interrupts (one for each direction).
>
> The logic is then: either there is only one unnamed interrupt on the
> standard port and this interrupt must be used for both directions
> (this is legacy bindings); or all the interrupts must be described and
> named 'uart-sum' (if available), 'uart-rx', 'uart-tx' and two separate
> handlers for each direction will be used.
>
> Suggested-by: Allen Yan <yanwei@xxxxxxxxxxx>
> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/tty/serial/mvebu-uart.c | 129 ++++++++++++++++++++++++++++++++++++----
> 1 file changed, 118 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
> index 46d10209637a..b52cbe8c0558 100644
> --- a/drivers/tty/serial/mvebu-uart.c
> +++ b/drivers/tty/serial/mvebu-uart.c
> @@ -79,7 +79,16 @@
> #define MVEBU_UART_TYPE "mvebu-uart"
> #define DRIVER_NAME "mvebu_serial"
>
> -/* Register offsets, different depending on the UART */
> +enum {
> + /* Either there is only one summed IRQ... */
> + UART_IRQ_SUM = 0,
> + /* ...or there are two separate IRQ for RX and TX */
> + UART_RX_IRQ = 0,
> + UART_TX_IRQ,
> + UART_IRQ_COUNT
> +};
> +
> +/* Diverging register offsets */
> struct uart_regs_layout {
> unsigned int rbr;
> unsigned int tsh;
> @@ -106,6 +115,8 @@ struct mvebu_uart_driver_data {
> struct mvebu_uart {
> struct uart_port *port;
> struct clk *clk;
> + int irq[UART_IRQ_COUNT];
> + unsigned char __iomem *nb;
> struct mvebu_uart_driver_data *data;
> };
>
> @@ -313,9 +324,32 @@ static irqreturn_t mvebu_uart_isr(int irq, void *dev_id)
> unsigned int st = readl(port->membase + UART_STAT);
>
> if (st & (STAT_RX_RDY(port) | STAT_OVR_ERR | STAT_FRM_ERR |
> + STAT_BRK_DET))
> + mvebu_uart_rx_chars(port, st);
> +
> + if (st & STAT_TX_RDY(port))
> + mvebu_uart_tx_chars(port, st);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t mvebu_uart_rx_isr(int irq, void *dev_id)
> +{
> + struct uart_port *port = (struct uart_port *)dev_id;
> + unsigned int st = readl(port->membase + UART_STAT);
> +
> + if (st & (STAT_RX_RDY(port) | STAT_OVR_ERR | STAT_FRM_ERR |
> STAT_BRK_DET))
> mvebu_uart_rx_chars(port, st);
>
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t mvebu_uart_tx_isr(int irq, void *dev_id)
> +{
> + struct uart_port *port = (struct uart_port *)dev_id;
> + unsigned int st = readl(port->membase + UART_STAT);
> +
> if (st & STAT_TX_RDY(port))
> mvebu_uart_tx_chars(port, st);
>
> @@ -324,6 +358,7 @@ static irqreturn_t mvebu_uart_isr(int irq, void *dev_id)
>
> static int mvebu_uart_startup(struct uart_port *port)
> {
> + struct mvebu_uart *mvuart = to_mvuart(port);
> unsigned int ctl;
> int ret;
>
> @@ -342,11 +377,37 @@ static int mvebu_uart_startup(struct uart_port *port)
> ctl |= CTRL_RX_RDY_INT(port);
> writel(ctl, port->membase + UART_INTR(port));
>
> - ret = request_irq(port->irq, mvebu_uart_isr, port->irqflags,
> - DRIVER_NAME, port);
> - if (ret) {
> - dev_err(port->dev, "failed to request irq\n");
> - return ret;
> + if (!mvuart->irq[UART_TX_IRQ]) {
> + /* Old bindings with just one interrupt (UART0 only) */
> + ret = devm_request_irq(port->dev, mvuart->irq[UART_IRQ_SUM],
> + mvebu_uart_isr, port->irqflags,
> + dev_name(port->dev), port);
> + if (ret) {
> + dev_err(port->dev, "unable to request IRQ %d\n",
> + mvuart->irq[UART_IRQ_SUM]);
> + return ret;
> + }
> + } else {
> + /* New bindings with an IRQ for RX and TX (both UART) */
> + ret = devm_request_irq(port->dev, mvuart->irq[UART_RX_IRQ],
> + mvebu_uart_rx_isr, port->irqflags,
> + dev_name(port->dev), port);
> + if (ret) {
> + dev_err(port->dev, "unable to request IRQ %d\n",
> + mvuart->irq[UART_RX_IRQ]);
> + return ret;
> + }
> +
> + ret = devm_request_irq(port->dev, mvuart->irq[UART_TX_IRQ],
> + mvebu_uart_tx_isr, port->irqflags,
> + dev_name(port->dev),
> + port);
> + if (ret) {
> + dev_err(port->dev, "unable to request IRQ %d\n",
> + mvuart->irq[UART_TX_IRQ]);
> + free_irq(mvuart->irq[UART_RX_IRQ], port);
If you register with devm_request_irq then you have to free with
devm_free_irq().
> + return ret;
> + }
> }
>
> return 0;
> @@ -354,9 +415,16 @@ static int mvebu_uart_startup(struct uart_port *port)
>
> static void mvebu_uart_shutdown(struct uart_port *port)
> {
> + struct mvebu_uart *mvuart = to_mvuart(port);
> +
> writel(0, port->membase + UART_INTR(port));
>
> - free_irq(port->irq, port);
> + if (!mvuart->irq[UART_TX_IRQ]) {
> + free_irq(mvuart->irq[UART_IRQ_SUM], port);
same here use devm_free_irq().
> + } else {
> + free_irq(mvuart->irq[UART_RX_IRQ], port);
> + free_irq(mvuart->irq[UART_TX_IRQ], port);
And here again.
Gregory
> + }
> }
>
> static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud)
> @@ -658,15 +726,15 @@ static const struct of_device_id mvebu_uart_of_match[];
> static int mvebu_uart_probe(struct platform_device *pdev)
> {
> struct resource *reg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> const struct of_device_id *match = of_match_device(mvebu_uart_of_match,
> &pdev->dev);
> struct uart_port *port;
> struct mvebu_uart *mvuart;
> + int irq;
> int ret;
>
> - if (!reg || !irq) {
> - dev_err(&pdev->dev, "no registers/irq defined\n");
> + if (!reg) {
> + dev_err(&pdev->dev, "no registers defined\n");
> return -EINVAL;
> }
>
> @@ -693,7 +761,12 @@ static int mvebu_uart_probe(struct platform_device *pdev)
> port->flags = UPF_FIXED_PORT;
> port->line = pdev->id;
>
> - port->irq = irq->start;
> + /*
> + * IRQ number is not stored in this structure because we may have two of
> + * them per port (RX and TX). Instead, use the driver UART structure
> + * array so called ->irq[].
> + */
> + port->irq = 0;
> port->irqflags = 0;
> port->mapbase = reg->start;
>
> @@ -728,6 +801,40 @@ static int mvebu_uart_probe(struct platform_device *pdev)
> port->uartclk = clk_get_rate(mvuart->clk);
> }
>
> + /* Manage interrupts */
> + memset(mvuart->irq, 0, UART_IRQ_COUNT);
> + if (platform_irq_count(pdev) == 1) {
> + /* Old bindings: no name on the single unamed UART0 IRQ */
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "unable to get UART IRQ\n");
> + return irq;
> + }
> +
> + mvuart->irq[UART_IRQ_SUM] = irq;
> + } else {
> + /*
> + * New bindings: named interrupts (RX, TX) for both UARTS,
> + * only make use of uart-rx and uart-tx interrupts, do not use
> + * uart-sum of UART0 port.
> + */
> + irq = platform_get_irq_byname(pdev, "uart-rx");
> + if (irq < 0) {
> + dev_err(&pdev->dev, "unable to get 'uart-rx' IRQ\n");
> + return irq;
> + }
> +
> + mvuart->irq[UART_RX_IRQ] = irq;
> +
> + irq = platform_get_irq_byname(pdev, "uart-tx");
> + if (irq < 0) {
> + dev_err(&pdev->dev, "unable to get 'uart-tx' IRQ\n");
> + return irq;
> + }
> +
> + mvuart->irq[UART_TX_IRQ] = irq;
> + }
> +
> /* UART Soft Reset*/
> writel(CTRL_SOFT_RST, port->membase + UART_CTRL(port));
> udelay(1);
> --
> 2.11.0
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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