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path: root/drivers/tty/serial/8250/8250_dw.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_dw.c')
-rw-r--r--drivers/tty/serial/8250/8250_dw.c292
1 files changed, 132 insertions, 160 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 06324f17a0cb..a5d319e4aae6 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -63,6 +63,9 @@ struct dw8250_data {
struct clk *pclk;
struct reset_control *rst;
struct uart_8250_dma dma;
+
+ unsigned int skip_autocfg:1;
+ unsigned int uart_16550_compatible:1;
};
#define BYT_PRV_CLK 0x800
@@ -224,10 +227,6 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
if (IS_ERR(d->clk) || !old)
goto out;
- /* Not requesting clock rates below 1.8432Mhz */
- if (baud < 115200)
- baud = 115200;
-
clk_disable_unprepare(d->clk);
rate = clk_round_rate(d->clk, baud * 16);
ret = clk_set_rate(d->clk, rate);
@@ -244,24 +243,77 @@ out:
serial8250_do_set_termios(p, termios, old);
}
-static bool dw8250_dma_filter(struct dma_chan *chan, void *param)
+/*
+ * dw8250_fallback_dma_filter will prevent the UART from getting just any free
+ * channel on platforms that have DMA engines, but don't have any channels
+ * assigned to the UART.
+ *
+ * REVISIT: This is a work around for limitation in the DMA Engine API. Once the
+ * core problem is fixed, this function is no longer needed.
+ */
+static bool dw8250_fallback_dma_filter(struct dma_chan *chan, void *param)
{
return false;
}
-static void dw8250_setup_port(struct uart_8250_port *up)
+static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
+{
+ return param == chan->device->dev->parent;
+}
+
+static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
{
- struct uart_port *p = &up->port;
- u32 reg = readl(p->membase + DW_UART_UCV);
+ if (p->dev->of_node) {
+ struct device_node *np = p->dev->of_node;
+ int id;
+
+ /* get index of serial line, if found in DT aliases */
+ id = of_alias_get_id(np, "serial");
+ if (id >= 0)
+ p->line = id;
+#ifdef CONFIG_64BIT
+ if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
+ p->serial_in = dw8250_serial_inq;
+ p->serial_out = dw8250_serial_outq;
+ p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
+ p->type = PORT_OCTEON;
+ data->usr_reg = 0x27;
+ data->skip_autocfg = true;
+ }
+#endif
+ } else if (has_acpi_companion(p->dev)) {
+ p->iotype = UPIO_MEM32;
+ p->regshift = 2;
+ p->serial_in = dw8250_serial_in32;
+ p->set_termios = dw8250_set_termios;
+ /* So far none of there implement the Busy Functionality */
+ data->uart_16550_compatible = true;
+ }
+
+ /* Platforms with iDMA */
+ if (platform_get_resource_byname(to_platform_device(p->dev),
+ IORESOURCE_MEM, "lpss_priv")) {
+ p->set_termios = dw8250_set_termios;
+ data->dma.rx_param = p->dev->parent;
+ data->dma.tx_param = p->dev->parent;
+ data->dma.fn = dw8250_idma_filter;
+ }
+}
+
+static void dw8250_setup_port(struct uart_port *p)
+{
+ struct uart_8250_port *up = up_to_u8250p(p);
+ u32 reg;
/*
* If the Component Version Register returns zero, we know that
* ADDITIONAL_FEATURES are not enabled. No need to go any further.
*/
+ reg = readl(p->membase + DW_UART_UCV);
if (!reg)
return;
- dev_dbg_ratelimited(p->dev, "Designware UART version %c.%c%c\n",
+ dev_dbg(p->dev, "Designware UART version %c.%c%c\n",
(reg >> 24) & 0xff, (reg >> 16) & 0xff, (reg >> 8) & 0xff);
reg = readl(p->membase + DW_UART_CPR);
@@ -273,7 +325,6 @@ static void dw8250_setup_port(struct uart_8250_port *up)
p->type = PORT_16550A;
p->flags |= UPF_FIXED_TYPE;
p->fifosize = DW_UART_CPR_FIFO_SIZE(reg);
- up->tx_loadsz = p->fifosize;
up->capabilities = UART_CAP_FIFO;
}
@@ -281,166 +332,91 @@ static void dw8250_setup_port(struct uart_8250_port *up)
up->capabilities |= UART_CAP_AFE;
}
-static int dw8250_probe_of(struct uart_port *p,
- struct dw8250_data *data)
+static int dw8250_probe(struct platform_device *pdev)
{
- struct device_node *np = p->dev->of_node;
- struct uart_8250_port *up = up_to_u8250p(p);
- u32 val;
- bool has_ucv = true;
- int id;
+ struct uart_8250_port uart = {};
+ struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ int irq = platform_get_irq(pdev, 0);
+ struct uart_port *p = &uart.port;
+ struct dw8250_data *data;
+ int err;
+ u32 val;
-#ifdef CONFIG_64BIT
- if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
- p->serial_in = dw8250_serial_inq;
- p->serial_out = dw8250_serial_outq;
- p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
- p->type = PORT_OCTEON;
- data->usr_reg = 0x27;
- has_ucv = false;
- } else
-#endif
- if (!of_property_read_u32(np, "reg-io-width", &val)) {
- switch (val) {
- case 1:
- break;
- case 4:
- p->iotype = UPIO_MEM32;
- p->serial_in = dw8250_serial_in32;
- p->serial_out = dw8250_serial_out32;
- break;
- default:
- dev_err(p->dev, "unsupported reg-io-width (%u)\n", val);
- return -EINVAL;
- }
+ if (!regs) {
+ dev_err(&pdev->dev, "no registers defined\n");
+ return -EINVAL;
}
- if (has_ucv)
- dw8250_setup_port(up);
-
- /* if we have a valid fifosize, try hooking up DMA here */
- if (p->fifosize) {
- up->dma = &data->dma;
- up->dma->rxconf.src_maxburst = p->fifosize / 4;
- up->dma->txconf.dst_maxburst = p->fifosize / 4;
+ if (irq < 0) {
+ if (irq != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "cannot get irq\n");
+ return irq;
}
- if (!of_property_read_u32(np, "reg-shift", &val))
+ spin_lock_init(&p->lock);
+ p->mapbase = regs->start;
+ p->irq = irq;
+ p->handle_irq = dw8250_handle_irq;
+ p->pm = dw8250_do_pm;
+ p->type = PORT_8250;
+ p->flags = UPF_SHARE_IRQ | UPF_FIXED_PORT;
+ p->dev = &pdev->dev;
+ p->iotype = UPIO_MEM;
+ p->serial_in = dw8250_serial_in;
+ p->serial_out = dw8250_serial_out;
+
+ p->membase = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
+ if (!p->membase)
+ return -ENOMEM;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->dma.fn = dw8250_fallback_dma_filter;
+ data->usr_reg = DW_UART_USR;
+ p->private_data = data;
+
+ data->uart_16550_compatible = device_property_read_bool(p->dev,
+ "snps,uart-16550-compatible");
+
+ err = device_property_read_u32(p->dev, "reg-shift", &val);
+ if (!err)
p->regshift = val;
- /* get index of serial line, if found in DT aliases */
- id = of_alias_get_id(np, "serial");
- if (id >= 0)
- p->line = id;
+ err = device_property_read_u32(p->dev, "reg-io-width", &val);
+ if (!err && val == 4) {
+ p->iotype = UPIO_MEM32;
+ p->serial_in = dw8250_serial_in32;
+ p->serial_out = dw8250_serial_out32;
+ }
- if (of_property_read_bool(np, "dcd-override")) {
+ if (device_property_read_bool(p->dev, "dcd-override")) {
/* Always report DCD as active */
data->msr_mask_on |= UART_MSR_DCD;
data->msr_mask_off |= UART_MSR_DDCD;
}
- if (of_property_read_bool(np, "dsr-override")) {
+ if (device_property_read_bool(p->dev, "dsr-override")) {
/* Always report DSR as active */
data->msr_mask_on |= UART_MSR_DSR;
data->msr_mask_off |= UART_MSR_DDSR;
}
- if (of_property_read_bool(np, "cts-override")) {
+ if (device_property_read_bool(p->dev, "cts-override")) {
/* Always report CTS as active */
data->msr_mask_on |= UART_MSR_CTS;
data->msr_mask_off |= UART_MSR_DCTS;
}
- if (of_property_read_bool(np, "ri-override")) {
+ if (device_property_read_bool(p->dev, "ri-override")) {
/* Always report Ring indicator as inactive */
data->msr_mask_off |= UART_MSR_RI;
data->msr_mask_off |= UART_MSR_TERI;
}
- return 0;
-}
-
-static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
-{
- struct device *dev = param;
-
- if (dev != chan->device->dev->parent)
- return false;
-
- return true;
-}
-
-static int dw8250_probe_acpi(struct uart_8250_port *up,
- struct dw8250_data *data)
-{
- struct uart_port *p = &up->port;
-
- dw8250_setup_port(up);
-
- p->iotype = UPIO_MEM32;
- p->serial_in = dw8250_serial_in32;
- p->serial_out = dw8250_serial_out32;
- p->regshift = 2;
-
- /* Platforms with iDMA */
- if (platform_get_resource_byname(to_platform_device(up->port.dev),
- IORESOURCE_MEM, "lpss_priv")) {
- data->dma.rx_param = up->port.dev->parent;
- data->dma.tx_param = up->port.dev->parent;
- data->dma.fn = dw8250_idma_filter;
- }
-
- up->dma = &data->dma;
- up->dma->rxconf.src_maxburst = p->fifosize / 4;
- up->dma->txconf.dst_maxburst = p->fifosize / 4;
-
- up->port.set_termios = dw8250_set_termios;
-
- return 0;
-}
-
-static int dw8250_probe(struct platform_device *pdev)
-{
- struct uart_8250_port uart = {};
- struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- int irq = platform_get_irq(pdev, 0);
- struct dw8250_data *data;
- int err;
-
- if (!regs) {
- dev_err(&pdev->dev, "no registers defined\n");
- return -EINVAL;
- }
-
- if (irq < 0) {
- if (irq != -EPROBE_DEFER)
- dev_err(&pdev->dev, "cannot get irq\n");
- return irq;
- }
-
- spin_lock_init(&uart.port.lock);
- uart.port.mapbase = regs->start;
- uart.port.irq = irq;
- uart.port.handle_irq = dw8250_handle_irq;
- uart.port.pm = dw8250_do_pm;
- uart.port.type = PORT_8250;
- uart.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
- uart.port.dev = &pdev->dev;
-
- uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
- resource_size(regs));
- if (!uart.port.membase)
- return -ENOMEM;
-
- data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- data->usr_reg = DW_UART_USR;
-
/* Always ask for fixed clock rate from a property. */
- device_property_read_u32(&pdev->dev, "clock-frequency",
- &uart.port.uartclk);
+ device_property_read_u32(p->dev, "clock-frequency", &p->uartclk);
/* If there is separate baudclk, get the rate from it. */
data->clk = devm_clk_get(&pdev->dev, "baudclk");
@@ -454,11 +430,11 @@ static int dw8250_probe(struct platform_device *pdev)
dev_warn(&pdev->dev, "could not enable optional baudclk: %d\n",
err);
else
- uart.port.uartclk = clk_get_rate(data->clk);
+ p->uartclk = clk_get_rate(data->clk);
}
/* If no clock rate is defined, fail. */
- if (!uart.port.uartclk) {
+ if (!p->uartclk) {
dev_err(&pdev->dev, "clock rate not defined\n");
return -EINVAL;
}
@@ -484,26 +460,22 @@ static int dw8250_probe(struct platform_device *pdev)
if (!IS_ERR(data->rst))
reset_control_deassert(data->rst);
- data->dma.rx_param = data;
- data->dma.tx_param = data;
- data->dma.fn = dw8250_dma_filter;
+ dw8250_quirks(p, data);
- uart.port.iotype = UPIO_MEM;
- uart.port.serial_in = dw8250_serial_in;
- uart.port.serial_out = dw8250_serial_out;
- uart.port.private_data = data;
+ /* If the Busy Functionality is not implemented, don't handle it */
+ if (data->uart_16550_compatible) {
+ p->serial_out = NULL;
+ p->handle_irq = NULL;
+ }
- if (pdev->dev.of_node) {
- err = dw8250_probe_of(&uart.port, data);
- if (err)
- goto err_reset;
- } else if (ACPI_HANDLE(&pdev->dev)) {
- err = dw8250_probe_acpi(&uart, data);
- if (err)
- goto err_reset;
- } else {
- err = -ENODEV;
- goto err_reset;
+ if (!data->skip_autocfg)
+ dw8250_setup_port(p);
+
+ /* If we have a valid fifosize, try hooking up DMA */
+ if (p->fifosize) {
+ data->dma.rxconf.src_maxburst = p->fifosize / 4;
+ data->dma.txconf.dst_maxburst = p->fifosize / 4;
+ uart.dma = &data->dma;
}
data->line = serial8250_register_8250_port(&uart);