Merge tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block

[linux-2.6-microblaze.git] / drivers / fpga / xilinx-spi.c

diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
index 2967aa2..27defa9 100644 (file)
--- a/drivers/fpga/xilinx-spi.c
+++ b/drivers/fpga/xilinx-spi.c
@@ -27,11 +27,22 @@ struct xilinx_spi_conf {
        struct gpio_desc *done;
 };
 
-static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
+static int get_done_gpio(struct fpga_manager *mgr)
 {
        struct xilinx_spi_conf *conf = mgr->priv;
+       int ret;
+
+       ret = gpiod_get_value(conf->done);
+
+       if (ret < 0)
+               dev_err(&mgr->dev, "Error reading DONE (%d)\n", ret);
 
-       if (!gpiod_get_value(conf->done))
+       return ret;
+}
+
+static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
+{
+       if (!get_done_gpio(mgr))
                return FPGA_MGR_STATE_RESET;
 
        return FPGA_MGR_STATE_UNKNOWN;
@@ -57,11 +68,21 @@ static int wait_for_init_b(struct fpga_manager *mgr, int value,
 
        if (conf->init_b) {
                while (time_before(jiffies, timeout)) {
-                       /* dump_state(conf, "wait for init_d .."); */
-                       if (gpiod_get_value(conf->init_b) == value)
+                       int ret = gpiod_get_value(conf->init_b);
+
+                       if (ret == value)
                                return 0;
+
+                       if (ret < 0) {
+                               dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret);
+                               return ret;
+                       }
+
                        usleep_range(100, 400);
                }
+
+               dev_err(&mgr->dev, "Timeout waiting for INIT_B to %s\n",
+                       value ? "assert" : "deassert");
                return -ETIMEDOUT;
        }
 
@@ -78,7 +99,7 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
        int err;
 
        if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
-               dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
+               dev_err(&mgr->dev, "Partial reconfiguration not supported\n");
                return -EINVAL;
        }
 
@@ -86,7 +107,6 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
 
        err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */
        if (err) {
-               dev_err(&mgr->dev, "INIT_B pin did not go low\n");
                gpiod_set_value(conf->prog_b, 0);
                return err;
        }
@@ -94,12 +114,10 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
        gpiod_set_value(conf->prog_b, 0);
 
        err = wait_for_init_b(mgr, 0, 0);
-       if (err) {
-               dev_err(&mgr->dev, "INIT_B pin did not go high\n");
+       if (err)
                return err;
-       }
 
-       if (gpiod_get_value(conf->done)) {
+       if (get_done_gpio(mgr)) {
                dev_err(&mgr->dev, "Unexpected DONE pin state...\n");
                return -EIO;
        }
@@ -152,25 +170,46 @@ static int xilinx_spi_write_complete(struct fpga_manager *mgr,
                                     struct fpga_image_info *info)
 {
        struct xilinx_spi_conf *conf = mgr->priv;
-       unsigned long timeout;
+       unsigned long timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+       bool expired = false;
+       int done;
        int ret;
 
-       if (gpiod_get_value(conf->done))
-               return xilinx_spi_apply_cclk_cycles(conf);
+       /*
+        * This loop is carefully written such that if the driver is
+        * scheduled out for more than 'timeout', we still check for DONE
+        * before giving up and we apply 8 extra CCLK cycles in all cases.
+        */
+       while (!expired) {
+               expired = time_after(jiffies, timeout);
 
-       timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
-
-       while (time_before(jiffies, timeout)) {
+               done = get_done_gpio(mgr);
+               if (done < 0)
+                       return done;
 
                ret = xilinx_spi_apply_cclk_cycles(conf);
                if (ret)
                        return ret;
 
-               if (gpiod_get_value(conf->done))
-                       return xilinx_spi_apply_cclk_cycles(conf);
+               if (done)
+                       return 0;
+       }
+
+       if (conf->init_b) {
+               ret = gpiod_get_value(conf->init_b);
+
+               if (ret < 0) {
+                       dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret);
+                       return ret;
+               }
+
+               dev_err(&mgr->dev,
+                       ret ? "CRC error or invalid device\n"
+                       : "Missing sync word or incomplete bitstream\n");
+       } else {
+               dev_err(&mgr->dev, "Timeout after config data transfer\n");
        }
 
-       dev_err(&mgr->dev, "Timeout after config data transfer.\n");
        return -ETIMEDOUT;
 }
 
@@ -220,18 +259,7 @@ static int xilinx_spi_probe(struct spi_device *spi)
        if (!mgr)
                return -ENOMEM;
 
-       spi_set_drvdata(spi, mgr);
-
-       return fpga_mgr_register(mgr);
-}
-
-static int xilinx_spi_remove(struct spi_device *spi)
-{
-       struct fpga_manager *mgr = spi_get_drvdata(spi);
-
-       fpga_mgr_unregister(mgr);
-
-       return 0;
+       return devm_fpga_mgr_register(&spi->dev, mgr);
 }
 
 static const struct of_device_id xlnx_spi_of_match[] = {
@@ -246,7 +274,6 @@ static struct spi_driver xilinx_slave_spi_driver = {
                .of_match_table = of_match_ptr(xlnx_spi_of_match),
        },
        .probe = xilinx_spi_probe,
-       .remove = xilinx_spi_remove,
 };
 
 module_spi_driver(xilinx_slave_spi_driver)