[PATCH v2 1/2] mtd: fsl-quadspi: Update slave device hwcap based on mode provided in dtsi file
From: Cyrille Pitchen <hidden>
Date: 2018-02-05 20:48:53
Also in:
linux-devicetree
Hi Yogesh, Le 02/02/2018 ? 06:31, Yogesh Gaur a ?crit?:
quoted hunk
FSL QuadSPI controller supports Single, dual, quad modes of operation. Mode information is available via "spi-tx-bus-width" and "spi-rx-bus-width" nodes of device tree for the connected slave device. Update read and write hwcap capability for slave device by reading "spi-rx-bus-width" and "spi-tx-bus-width" respectively. Assign hwcaps mask to minimal caps for the slave node i.e. SNOR_HWCAPS_READ | SNOR_HWCAPS_PP If value not provided in device tree file, then fallback to default mode i.e. SNOR_HWCAPS_READ_1_1_4 and SNOR_HWCAPS_PP. Signed-off-by: Prabhakar Kushwaha <redacted> Signed-off-by: Yogesh Gaur <redacted> --- Changes for v2: - None drivers/mtd/spi-nor/fsl-quadspi.c | 56 +++++++++++++++++++++++++++++++++++---- 1 file changed, 51 insertions(+), 5 deletions(-)diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c index b9c5918..1503e0c 100644 --- a/drivers/mtd/spi-nor/fsl-quadspi.c +++ b/drivers/mtd/spi-nor/fsl-quadspi.c@@ -994,17 +994,14 @@ static void fsl_qspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops) static int fsl_qspi_probe(struct platform_device *pdev) { - const struct spi_nor_hwcaps hwcaps = { - .mask = SNOR_HWCAPS_READ_1_1_4 | - SNOR_HWCAPS_PP, - }; + struct spi_nor_hwcaps hwcaps; struct device_node *np = pdev->dev.of_node; struct device *dev = &pdev->dev; struct fsl_qspi *q; struct resource *res; struct spi_nor *nor; struct mtd_info *mtd; - int ret, i = 0; + int ret, i = 0, value; q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL); if (!q)@@ -1077,6 +1074,10 @@ static int fsl_qspi_probe(struct platform_device *pdev) /* iterate the subnodes. */ for_each_available_child_of_node(dev->of_node, np) { + /* Reset hwcaps mask to minimal caps for the slave node. */ + hwcaps.mask = SNOR_HWCAPS_READ | SNOR_HWCAPS_PP; + value = 0; + /* skip the holes */ if (!q->has_second_chip) i *= 2;@@ -1106,6 +1107,51 @@ static int fsl_qspi_probe(struct platform_device *pdev) /* set the chip address for READID */ fsl_qspi_set_base_addr(q, nor); + /* + * If spi-rx-bus-width and spi-tx-bus-width not defined assign + * default hardware capabilities SNOR_HWCAPS_READ_1_1_4 and + * SNOR_HWCAPS_PP supported by the Quad-SPI controller. + */ + if (!of_property_read_u32(np, "spi-rx-bus-width", &value)) { + switch (value) { + case 1: + hwcaps.mask |= SNOR_HWCAPS_READ | + SNOR_HWCAPS_READ_FAST; + break; + case 2: + hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2 | + SNOR_HWCAPS_READ_1_2_2;
I guess there is a misunderstanding in the meaning of spi-rx-bus-width and spi-tx-bus_width. spi-rx-bus-width = <N>, resp. spi-tx-bus-width = <N>, means the SPI controller can receive, resp. send, data on N I/O Lines. Then let's take the example of some Fast Read X-Y-Z command: the op code is *sent* on X I/O lines: you need to check spi-tx-bus-width the address/mode/dummy bits are *sent* on Y I/O lines: check spi-tx-bus-width too the data bits are *received* on Z I/O lines: check spi-rx-bus_width.
+ break; + case 4: + hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4 | + SNOR_HWCAPS_READ_1_4_4;
The same here: to allow SPI 1-4-4, you have to check that spi-tx-bus-width == 4.
So your usage of spi-{tx|rx}-bus-width is not consistent with the usage done in
the SPI subsystem. Please have a look at drivers/mtd/devices/m25p80.c, especially
how the SPI_RX_QUAD and SPI_TX_QUAD flags are used in the m25p_probe() function
to have a better idea of how it should work.
Also have a look at of_spi_parse_dt() in drivers/spi/spi.c, to figure out how the
SPI_{TX|RX}_{DUAL|QUAD} flags are set according to the spi-{tx|rx}-bus-width DT
properties.
+ break; + default: + dev_err(dev, + "spi-rx-bus-width %d not supported\n", + value); + break; + } + } else + hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
Not sure whether it passes checkpatch, you may have to add { } for the else
statement even if there is a single line as the if statement use { }.
Personally I don't mind that much. Please just check that your patch passes
checkpatch verification and it will be okay for me :)
Best regards,
Cyrille
+
+ if (!of_property_read_u32(np, "spi-tx-bus-width", &value)) {
+ switch (value) {
+ case 1:
+ hwcaps.mask |= SNOR_HWCAPS_PP;
+ break;
+ case 4:
+ hwcaps.mask |= SNOR_HWCAPS_PP_1_1_4 |
+ SNOR_HWCAPS_PP_1_4_4;
+ break;
+ default:
+ dev_err(dev,
+ "spi-tx-bus-width %d not supported\n",
+ value);
+ break;
+ }
+ }
+
ret = spi_nor_scan(nor, NULL, &hwcaps);
if (ret)
goto mutex_failed;