The "soft uart" mechanism is a workaround for a silicon bug which (as
far as I know) only affects some PPC-based SOCs.
The code that determines which microcode blob to request relies on
some powerpc-specific bits (e.g. the mfspr(SPRN_SVR) and hence also
the asm/reg.h header). This makes it a little awkward to allow this
driver to be built for non-PPC based SOCs with a QE, even if they are
not affected by that silicon bug and thus don't need any of the Soft
UART logic.
There's no way around guarding those bits with some ifdeffery, so to
keep that isolated, factor out the
do-we-need-soft-uart-and-if-so-handle-the-firmware to a separate
function, which we can then easily stub out for non-PPC.
Signed-off-by: Rasmus Villemoes <[email protected]>
---
drivers/tty/serial/ucc_uart.c | 110 ++++++++++++++++++----------------
1 file changed, 58 insertions(+), 52 deletions(-)
diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
index 8a378ee5d34f..f286e91714cb 100644
--- a/drivers/tty/serial/ucc_uart.c
+++ b/drivers/tty/serial/ucc_uart.c
@@ -1183,70 +1183,76 @@ static void uart_firmware_cont(const struct firmware *fw, void *context)
release_firmware(fw);
}
-static int ucc_uart_probe(struct platform_device *ofdev)
+static int soft_uart_init(struct platform_device *ofdev)
{
struct device_node *np = ofdev->dev.of_node;
- const unsigned int *iprop; /* Integer OF properties */
- const char *sprop; /* String OF properties */
- struct uart_qe_port *qe_port = NULL;
- struct resource res;
+ struct qe_firmware_info *qe_fw_info;
int ret;
- /*
- * Determine if we need Soft-UART mode
- */
if (of_find_property(np, "soft-uart", NULL)) {
dev_dbg(&ofdev->dev, "using Soft-UART mode\n");
soft_uart = 1;
+ } else {
+ return 0;
}
- /*
- * If we are using Soft-UART, determine if we need to upload the
- * firmware, too.
- */
- if (soft_uart) {
- struct qe_firmware_info *qe_fw_info;
-
- qe_fw_info = qe_get_firmware_info();
-
- /* Check if the firmware has been uploaded. */
- if (qe_fw_info && strstr(qe_fw_info->id, "Soft-UART")) {
- firmware_loaded = 1;
- } else {
- char filename[32];
- unsigned int soc;
- unsigned int rev_h;
- unsigned int rev_l;
-
- soc = soc_info(&rev_h, &rev_l);
- if (!soc) {
- dev_err(&ofdev->dev, "unknown CPU model\n");
- return -ENXIO;
- }
- sprintf(filename, "fsl_qe_ucode_uart_%u_%u%u.bin",
- soc, rev_h, rev_l);
-
- dev_info(&ofdev->dev, "waiting for firmware %s\n",
- filename);
+ qe_fw_info = qe_get_firmware_info();
- /*
- * We call request_firmware_nowait instead of
- * request_firmware so that the driver can load and
- * initialize the ports without holding up the rest of
- * the kernel. If hotplug support is enabled in the
- * kernel, then we use it.
- */
- ret = request_firmware_nowait(THIS_MODULE,
- FW_ACTION_HOTPLUG, filename, &ofdev->dev,
- GFP_KERNEL, &ofdev->dev, uart_firmware_cont);
- if (ret) {
- dev_err(&ofdev->dev,
- "could not load firmware %s\n",
- filename);
- return ret;
- }
+ /* Check if the firmware has been uploaded. */
+ if (qe_fw_info && strstr(qe_fw_info->id, "Soft-UART")) {
+ firmware_loaded = 1;
+ } else {
+ char filename[32];
+ unsigned int soc;
+ unsigned int rev_h;
+ unsigned int rev_l;
+
+ soc = soc_info(&rev_h, &rev_l);
+ if (!soc) {
+ dev_err(&ofdev->dev, "unknown CPU model\n");
+ return -ENXIO;
+ }
+ sprintf(filename, "fsl_qe_ucode_uart_%u_%u%u.bin",
+ soc, rev_h, rev_l);
+
+ dev_info(&ofdev->dev, "waiting for firmware %s\n",
+ filename);
+
+ /*
+ * We call request_firmware_nowait instead of
+ * request_firmware so that the driver can load and
+ * initialize the ports without holding up the rest of
+ * the kernel. If hotplug support is enabled in the
+ * kernel, then we use it.
+ */
+ ret = request_firmware_nowait(THIS_MODULE,
+ FW_ACTION_HOTPLUG, filename, &ofdev->dev,
+ GFP_KERNEL, &ofdev->dev, uart_firmware_cont);
+ if (ret) {
+ dev_err(&ofdev->dev,
+ "could not load firmware %s\n",
+ filename);
+ return ret;
}
}
+ return 0;
+}
+
+static int ucc_uart_probe(struct platform_device *ofdev)
+{
+ struct device_node *np = ofdev->dev.of_node;
+ const unsigned int *iprop; /* Integer OF properties */
+ const char *sprop; /* String OF properties */
+ struct uart_qe_port *qe_port = NULL;
+ struct resource res;
+ int ret;
+
+ /*
+ * Determine if we need Soft-UART mode
+ */
+ ret = soft_uart_init(ofdev);
+ if (ret)
+ return ret;
qe_port = kzalloc(sizeof(struct uart_qe_port), GFP_KERNEL);
if (!qe_port) {
--
2.23.0
On Fri, Nov 8, 2019 at 7:03 AM Rasmus Villemoes
<[email protected]> wrote:
>
> - /*
> - * Determine if we need Soft-UART mode
> - */
> if (of_find_property(np, "soft-uart", NULL)) {
> dev_dbg(&ofdev->dev, "using Soft-UART mode\n");
> soft_uart = 1;
> + } else {
> + return 0;
> }
How about:
if (!of_find_property(np, "soft-uart", NULL))
return 0;
And I think you should be able to get rid of the "soft_uart" variable.
On 14/11/2019 06.14, Timur Tabi wrote:
> On Fri, Nov 8, 2019 at 7:03 AM Rasmus Villemoes
> <[email protected]> wrote:
>>
>> - /*
>> - * Determine if we need Soft-UART mode
>> - */
>> if (of_find_property(np, "soft-uart", NULL)) {
>> dev_dbg(&ofdev->dev, "using Soft-UART mode\n");
>> soft_uart = 1;
>> + } else {
>> + return 0;
>> }
>
> How about:
>
> if (!of_find_property(np, "soft-uart", NULL))
> return 0;
of_property_read_bool() if anything. But I didn't want to do that kind
of transformation - just a pure "move this code out and fix the
indentation" with the minor edits needed to hook it back up where it
came from.
> And I think you should be able to get rid of the "soft_uart" variable.
Eh, no, it's used in several other places in the driver. I kind of hope
gcc is smart enough to see that in the !PPC32 case it is a static,
never-assigned-to, never-escapes variable so all the "if (soft_uart)"
branches go away, but that's not really very important.
Rasmus