| Message ID | 1345544302-12406-1-git-send-email-matthew.leach@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/21/2012 05:18 AM, Matthew Leach wrote: > If the order of UART nodes is changed in the device tree, then tty dev > devices are attached to different serial ports causing the console to > be directed to a different physical serial port. The "serial" aliases > in the device tree should prevent this. > > This patch ensures that the UART driver creates tty devices that > honour these aliases if a device tree is present. > > Signed-off-by: Matthew Leach <matthew.leach@arm.com> One comment/question below, but otherwise: Acked-by: Rob Herring <rob.herring@calxeda.com> > --- > drivers/tty/serial/amba-pl011.c | 39 +++++++++++++++++++++++++++++++++++++++ > 1 files changed, 39 insertions(+), 0 deletions(-) > > diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c > index c17923e..5919599 100644 > --- a/drivers/tty/serial/amba-pl011.c > +++ b/drivers/tty/serial/amba-pl011.c > @@ -52,6 +52,7 @@ > #include <linux/scatterlist.h> > #include <linux/delay.h> > #include <linux/types.h> > +#include <linux/of_device.h> > #include <linux/pinctrl/consumer.h> > > #include <asm/io.h> > @@ -1869,6 +1870,42 @@ static struct uart_driver amba_reg = { > .cons = AMBA_CONSOLE, > }; > > +#ifdef CONFIG_OF Now that we have IS_ENABLED, perhaps we want to put this inside the function instead? if (!IS_ENABLED(CONFIG_OF)) return index; > +static int pl011_probe_dt_alias(int index, struct device *dev) > +{ > + struct device_node *np; > + static bool seen_dev_with_alias = false; > + static bool seen_dev_without_alias = false; > + int ret = index; > + > + np = dev->of_node; > + if (!np) > + return ret; > + > + ret = of_alias_get_id(np, "serial"); > + if (IS_ERR_VALUE(ret)) { > + seen_dev_without_alias = true; > + ret = index; > + } else { > + seen_dev_with_alias = true; > + if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) { > + dev_warn(dev, "requested serial port %d not available.\n", ret); > + ret = index; > + } > + } > + > + if (seen_dev_with_alias && seen_dev_without_alias) > + dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n"); > + > + return ret; > +} > +#else > +static int pl011_probe_dt_alias(int index, struct device *dev) > +{ > + return index; > +} > +#endif > + > static int pl011_probe(struct amba_device *dev, const struct amba_id *id) > { > struct uart_amba_port *uap; > @@ -1891,6 +1928,8 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id) > goto out; > } > > + i = pl011_probe_dt_alias(i, &dev->dev); > + > base = ioremap(dev->res.start, resource_size(&dev->res)); > if (!base) { > ret = -ENOMEM; >
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index c17923e..5919599 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -52,6 +52,7 @@ #include <linux/scatterlist.h> #include <linux/delay.h> #include <linux/types.h> +#include <linux/of_device.h> #include <linux/pinctrl/consumer.h> #include <asm/io.h> @@ -1869,6 +1870,42 @@ static struct uart_driver amba_reg = { .cons = AMBA_CONSOLE, }; +#ifdef CONFIG_OF +static int pl011_probe_dt_alias(int index, struct device *dev) +{ + struct device_node *np; + static bool seen_dev_with_alias = false; + static bool seen_dev_without_alias = false; + int ret = index; + + np = dev->of_node; + if (!np) + return ret; + + ret = of_alias_get_id(np, "serial"); + if (IS_ERR_VALUE(ret)) { + seen_dev_without_alias = true; + ret = index; + } else { + seen_dev_with_alias = true; + if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) { + dev_warn(dev, "requested serial port %d not available.\n", ret); + ret = index; + } + } + + if (seen_dev_with_alias && seen_dev_without_alias) + dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n"); + + return ret; +} +#else +static int pl011_probe_dt_alias(int index, struct device *dev) +{ + return index; +} +#endif + static int pl011_probe(struct amba_device *dev, const struct amba_id *id) { struct uart_amba_port *uap; @@ -1891,6 +1928,8 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id) goto out; } + i = pl011_probe_dt_alias(i, &dev->dev); + base = ioremap(dev->res.start, resource_size(&dev->res)); if (!base) { ret = -ENOMEM;
If the order of UART nodes is changed in the device tree, then tty dev devices are attached to different serial ports causing the console to be directed to a different physical serial port. The "serial" aliases in the device tree should prevent this. This patch ensures that the UART driver creates tty devices that honour these aliases if a device tree is present. Signed-off-by: Matthew Leach <matthew.leach@arm.com> --- drivers/tty/serial/amba-pl011.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 files changed, 39 insertions(+), 0 deletions(-)