[Patch v2 3/9] spi: bcm-qspi: Handle lack of MSPI_REV offset

From: Kamal Dasu
Date: Sun Apr 19 2020 - 15:26:27 EST


Older MIPS chips have a QSPI/MSPI controller that does not have the
MSPI_REV offset, reading from that offset will cause a bus error. Match
their compatible string and do not perform a read from that register in
that case.

Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
---
drivers/spi/spi-bcm-qspi.c | 50 ++++++++++++++++++++++++++++++++++++--
1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index 74f4579c3f6a..d901dcb10d06 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -91,6 +91,7 @@
#define MSPI_MSPI_STATUS 0x020
#define MSPI_CPTQP 0x024
#define MSPI_SPCR3 0x028
+#define MSPI_REV 0x02c
#define MSPI_TXRAM 0x040
#define MSPI_RXRAM 0x0c0
#define MSPI_CDRAM 0x140
@@ -217,6 +218,8 @@ struct bcm_qspi {
struct bcm_qspi_dev_id *dev_ids;
struct completion mspi_done;
struct completion bspi_done;
+ u8 mspi_maj_rev;
+ u8 mspi_min_rev;
};

static inline bool has_bspi(struct bcm_qspi *qspi)
@@ -1190,8 +1193,35 @@ static const struct spi_controller_mem_ops bcm_qspi_mem_ops = {
.exec_op = bcm_qspi_exec_mem_op,
};

+struct bcm_qspi_data {
+ bool has_mspi_rev;
+};
+
+static const struct bcm_qspi_data bcm_qspi_no_rev_data = {
+ .has_mspi_rev = false,
+};
+
+static const struct bcm_qspi_data bcm_qspi_rev_data = {
+ .has_mspi_rev = true,
+};
+
static const struct of_device_id bcm_qspi_of_match[] = {
- { .compatible = "brcm,spi-bcm-qspi" },
+ {
+ .compatible = "brcm,spi-bcm7425-qspi",
+ .data = &bcm_qspi_no_rev_data,
+ },
+ {
+ .compatible = "brcm,spi-bcm7429-qspi",
+ .data = &bcm_qspi_no_rev_data,
+ },
+ {
+ .compatible = "brcm,spi-bcm7435-qspi",
+ .data = &bcm_qspi_no_rev_data,
+ },
+ {
+ .compatible = "brcm,spi-bcm-qspi",
+ .data = &bcm_qspi_rev_data,
+ },
{},
};
MODULE_DEVICE_TABLE(of, bcm_qspi_of_match);
@@ -1199,12 +1229,15 @@ MODULE_DEVICE_TABLE(of, bcm_qspi_of_match);
int bcm_qspi_probe(struct platform_device *pdev,
struct bcm_qspi_soc_intc *soc_intc)
{
+ const struct of_device_id *of_id = NULL;
+ const struct bcm_qspi_data *data;
struct device *dev = &pdev->dev;
struct bcm_qspi *qspi;
struct spi_master *master;
struct resource *res;
int irq, ret = 0, num_ints = 0;
u32 val;
+ u32 rev = 0;
const char *name = NULL;
int num_irqs = ARRAY_SIZE(qspi_irq_tab);

@@ -1212,9 +1245,12 @@ int bcm_qspi_probe(struct platform_device *pdev,
if (!dev->of_node)
return -ENODEV;

- if (!of_match_node(bcm_qspi_of_match, dev->of_node))
+ of_id = of_match_node(bcm_qspi_of_match, dev->of_node);
+ if (!of_id)
return -ENODEV;

+ data = of_id->data;
+
master = spi_alloc_master(dev, sizeof(struct bcm_qspi));
if (!master) {
dev_err(dev, "error allocating spi_master\n");
@@ -1349,6 +1385,16 @@ int bcm_qspi_probe(struct platform_device *pdev,
qspi->base_clk = clk_get_rate(qspi->clk);
qspi->max_speed_hz = qspi->base_clk / (QSPI_SPBR_MIN * 2);

+ if (data->has_mspi_rev) {
+ rev = bcm_qspi_read(qspi, MSPI, MSPI_REV);
+ /* some older revs do not have a MSPI_REV register */
+ if ((rev & 0xff) == 0xff)
+ rev = 0;
+ }
+
+ qspi->mspi_maj_rev = (rev >> 4) & 0xf;
+ qspi->mspi_min_rev = rev & 0xf;
+
bcm_qspi_hw_init(qspi);
init_completion(&qspi->mspi_done);
init_completion(&qspi->bspi_done);
--
2.17.1