[PATCH v2] serial: ns16550: Fix ordering of getting base address
Bin Meng
bmeng.cn at gmail.com
Fri Apr 3 14:46:19 CEST 2020
Currently the driver gets ns16550 base address in the driver
probe() routine, which may potentially break any ns16550 wrapper
driver that does additional initialization before calling
ns16550_serial_probe().
Things are complicated that we need consider ns16550 devices on
both simple-bus and PCI bus. To fix the issue we move the base
address assignment for simple-bus ns16550 device back to the
ofdata_to_platdata(), and assign base address for PCI ns16550
device in ns16550_serial_probe().
This is still not perfect. Ideally if any PCI bus based ns16550
wrapper driver tries to access plat->base before calling probe(),
it is subject to break.
Fixes: 720f9e1fdb0c9 ("serial: ns16550: Move PCI access from ofdata_to_platdata() to probe()")
Reported-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
Tested-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
Tested-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
---
Changes in v2:
- not to break Fixes, etc to two or more lines in the commit message
- add the same CONFIG_SYS_NS16550_PORT_MAPPED ifdefs in the PCI case
drivers/serial/ns16550.c | 53 ++++++++++++++++++++++++------------------------
1 file changed, 27 insertions(+), 26 deletions(-)
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index c1b303f..cb464a5 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -479,39 +479,28 @@ static int ns16550_serial_getinfo(struct udevice *dev,
return 0;
}
-#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
-static int ns1655_serial_set_base_addr(struct udevice *dev)
-{
- fdt_addr_t addr;
- struct ns16550_platdata *plat;
-
- plat = dev_get_platdata(dev);
-
- addr = dev_read_addr_pci(dev);
- if (addr == FDT_ADDR_T_NONE)
- return -EINVAL;
-
-#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
- plat->base = addr;
-#else
- plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
-#endif
-
- return 0;
-}
-#endif
-
int ns16550_serial_probe(struct udevice *dev)
{
+ struct ns16550_platdata *plat = dev->platdata;
struct NS16550 *const com_port = dev_get_priv(dev);
struct reset_ctl_bulk reset_bulk;
+ fdt_addr_t addr;
int ret;
-#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
- ret = ns1655_serial_set_base_addr(dev);
- if (ret)
- return ret;
+ /*
+ * If we are on PCI bus, either directly attached to a PCI root port,
+ * or via a PCI bridge, assign platdata->base before probing hardware.
+ */
+ if (device_is_on_pci_bus(dev)) {
+ addr = devfdt_get_addr_pci(dev);
+ if (addr == FDT_ADDR_T_NONE)
+ return -EINVAL;
+#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
+ plat->base = addr;
+#else
+ plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
#endif
+ }
ret = reset_get_bulk(dev, &reset_bulk);
if (!ret)
@@ -535,9 +524,21 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
{
struct ns16550_platdata *plat = dev->platdata;
const u32 port_type = dev_get_driver_data(dev);
+ fdt_addr_t addr;
struct clk clk;
int err;
+ addr = dev_read_addr(dev);
+ if (addr != FDT_ADDR_T_NONE) {
+#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
+ plat->base = addr;
+#else
+ plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
+#endif
+ } else if (!device_is_on_pci_bus(dev)) {
+ return -EINVAL;
+ }
+
plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0);
plat->reg_shift = dev_read_u32_default(dev, "reg-shift", 0);
plat->reg_width = dev_read_u32_default(dev, "reg-io-width", 1);
--
2.7.4
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