staging: pi433: validate max bit_rate based on modulation used

Max bit rate is dependent on which modulation is used. Previous
validation routine only took into consideration min bit rate which can
lead a misconfiguration of the rf69 chip causing the packets not to be
sent/read.

This patch enhances that input check in set_bit_rate to account for
modulation values and their respective max bit rate

Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
Link: https://lore.kernel.org/r/20220118230555.GA4961@mail.google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/pi433/TODO b/drivers/staging/pi433/TODO
index 63a40bfcc67e6c3e343f1aeb8bd6caf8f248a83c..b9e6c01a02e00fd95beda0888703772d4d70c799 100644 (file)
--- a/drivers/staging/pi433/TODO
+++ b/drivers/staging/pi433/TODO
@@ -3,3 +3,5 @@
 * currently the code introduces new IOCTLs. I'm afraid this is a bad idea.
   -> Replace this with another interface, hints are welcome!
 * Some missing data (marked with ###) needs to be added in the documentation
+* Change (struct pi433_tx_cfg)->bit_rate to be a u32 so that we can support
+    bit rates up to 300kbps per the spec.

diff --git a/drivers/staging/pi433/rf69.c b/drivers/staging/pi433/rf69.c
index f4ac17adcd8381d42ceb361c7eb3f53160deb454..d60514a840c28abcc2923c74ded0b1fb987663d0 100644 (file)
--- a/drivers/staging/pi433/rf69.c
+++ b/drivers/staging/pi433/rf69.c
@@ -229,9 +229,17 @@ int rf69_set_bit_rate(struct spi_device *spi, u16 bit_rate)
        u32 bit_rate_reg;
        u8 msb;
        u8 lsb;
+       enum modulation mod;
+
+       // check if modulation is configured
+       mod = rf69_get_modulation(spi);
+       if (mod == UNDEF) {
+               dev_dbg(&spi->dev, "setBitRate: modulation is undefined");
+               return -EINVAL;
+       }
 
        // check input value
-       if (bit_rate < 1200) {
+       if (bit_rate < 1200 || (mod == OOK && bit_rate > 32768)) {
                dev_dbg(&spi->dev, "setBitRate: illegal input param");
                return -EINVAL;
        }