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

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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 <carlos.song@nxp.com>
Link: https://patch.msgid.link/20240820070658.672127-1-carlos.song@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Carlos Song 2024-08-20 15:06:58 +08:00 committed by Mark Brown
parent 57d5af2660
commit 783bf5d09f
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 29 additions and 2 deletions
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31
drivers/spi/spi-fsl-lpspi.c
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@ -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);