spi: spi-fsl-lpspi: limit PRESCALE bit in TCR register

Commit Message

Carlos Song Aug. 20, 2024, 7:06 a.m. UTC

From: Carlos Song <[e-mail]>

Referring to the errata ERR051608 of I.MX93, LPSPI TCR[PRESCALE]
can only be configured to be 0 or 1, other values are not valid
and will cause LPSPI to not work.

Add the prescale limitation for LPSPI in I.MX93. Other platforms
are not affected.

Signed-off-by: Carlos Song <[e-mail]>
---
 drivers/spi/spi-fsl-lpspi.c | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

Comments

Mark Brown Aug. 20, 2024, 1:27 p.m. UTC | #1

On Tue, 20 Aug 2024 15:06:58 +0800, [e-mail] wrote:
> Referring to the errata ERR051608 of I.MX93, LPSPI TCR[PRESCALE]
> can only be configured to be 0 or 1, other values are not valid
> and will cause LPSPI to not work.
> 
> Add the prescale limitation for LPSPI in I.MX93. Other platforms
> are not affected.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: spi-fsl-lpspi: limit PRESCALE bit in TCR register
      commit: 783bf5d09f86b9736605f3e01a3472e55ef98ff8

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Patch

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index be261ac09df8..350c5d91d869 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -82,6 +82,10 @@ 
 #define TCR_RXMSK	BIT(19)
 #define TCR_TXMSK	BIT(18)
 
+struct fsl_lpspi_devtype_data {
+	u8 prescale_max;
+};
+
 struct lpspi_config {
 	u8 bpw;
 	u8 chip_select;
@@ -119,10 +123,25 @@  struct fsl_lpspi_data {
 	bool usedma;
 	struct completion dma_rx_completion;
 	struct completion dma_tx_completion;
+
+	const struct fsl_lpspi_devtype_data *devtype_data;
+};
+
+/*
+ * ERR051608 fixed or not:
+ * https://www.nxp.com/docs/en/errata/i.MX93_1P87f.pdf
+ */
+static struct fsl_lpspi_devtype_data imx93_lpspi_devtype_data = {
+	.prescale_max = 1,
+};
+
+static struct fsl_lpspi_devtype_data imx7ulp_lpspi_devtype_data = {
+	.prescale_max = 8,
 };
 
 static const struct of_device_id fsl_lpspi_dt_ids[] = {
-	{ .compatible = "fsl,imx7ulp-spi", },
+	{ .compatible = "fsl,imx7ulp-spi", .data = &imx7ulp_lpspi_devtype_data,},
+	{ .compatible = "fsl,imx93-spi", .data = &imx93_lpspi_devtype_data,},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, fsl_lpspi_dt_ids);
@@ -297,9 +316,11 @@  static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
 {
 	struct lpspi_config config = fsl_lpspi->config;
 	unsigned int perclk_rate, scldiv, div;
+	u8 prescale_max;
 	u8 prescale;
 
 	perclk_rate = clk_get_rate(fsl_lpspi->clk_per);
+	prescale_max = fsl_lpspi->devtype_data->prescale_max;
 
 	if (!config.speed_hz) {
 		dev_err(fsl_lpspi->dev,
@@ -315,7 +336,7 @@  static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
 
 	div = DIV_ROUND_UP(perclk_rate, config.speed_hz);
 
-	for (prescale = 0; prescale < 8; prescale++) {
+	for (prescale = 0; prescale < prescale_max; prescale++) {
 		scldiv = div / (1 << prescale) - 2;
 		if (scldiv < 256) {
 			fsl_lpspi->config.prescale = prescale;
@@ -822,6 +843,7 @@  static int fsl_lpspi_init_rpm(struct fsl_lpspi_data *fsl_lpspi)
 
 static int fsl_lpspi_probe(struct platform_device *pdev)
 {
+	const struct fsl_lpspi_devtype_data *devtype_data;
 	struct fsl_lpspi_data *fsl_lpspi;
 	struct spi_controller *controller;
 	struct resource *res;
@@ -830,6 +852,10 @@  static int fsl_lpspi_probe(struct platform_device *pdev)
 	u32 temp;
 	bool is_target;
 
+	devtype_data = of_device_get_match_data(&pdev->dev);
+	if (!devtype_data)
+		return -ENODEV;
+
 	is_target = of_property_read_bool((&pdev->dev)->of_node, "spi-slave");
 	if (is_target)
 		controller = devm_spi_alloc_target(&pdev->dev,
@@ -848,6 +874,7 @@  static int fsl_lpspi_probe(struct platform_device *pdev)
 	fsl_lpspi->is_target = is_target;
 	fsl_lpspi->is_only_cs1 = of_property_read_bool((&pdev->dev)->of_node,
 						"fsl,spi-only-use-cs1-sel");
+	fsl_lpspi->devtype_data = devtype_data;
 
 	init_completion(&fsl_lpspi->xfer_done);