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| author | Mayuresh Chitale <mchitale@ventanamicro.com> | 2023-11-16 22:13:36 +0530 |
|---|---|---|
| committer | Michal Simek <michal.simek@amd.com> | 2023-12-13 08:58:06 +0100 |
| commit | 218539e2e7fab46bb35fb09b38ac4de4480e7836 (patch) | |
| tree | 08b9400777fae5191086c8936d1cf364a39a3327 /drivers/spi | |
| parent | 954d437d266207e6cb6c5d5706891ddde3671b6e (diff) | |
| download | u-boot-218539e2e7fab46bb35fb09b38ac4de4480e7836.tar.gz u-boot-218539e2e7fab46bb35fb09b38ac4de4480e7836.tar.bz2 u-boot-218539e2e7fab46bb35fb09b38ac4de4480e7836.zip | |
drivers: xilinx_spi: Probe fifo_depth at runtime
If the fifo-size DT parameter is not provided then probe the
controller's fifo depth at runtime. This is ported from a patch
in the Linux Xilinx SPI driver.
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/1422029330-10971-5-git-send-email-ricardo.ribalda@gmail.com
Tested-by: Love Kumar <love.kumar@amd.com>
Link: https://lore.kernel.org/r/20231116164336.140171-4-mchitale@ventanamicro.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/xilinx_spi.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c index b63cda2091..94ddf4967e 100644 --- a/drivers/spi/xilinx_spi.c +++ b/drivers/spi/xilinx_spi.c @@ -109,6 +109,27 @@ struct xilinx_spi_priv { u8 startup; }; +static int xilinx_spi_find_buffer_size(struct xilinx_spi_regs *regs) +{ + u8 sr; + int n_words = 0; + + /* + * Before the buffer_size detection reset the core + * to make sure to start with a clean state. + */ + writel(SPISSR_RESET_VALUE, ®s->srr); + + /* Fill the Tx FIFO with as many words as possible */ + do { + writel(0, ®s->spidtr); + sr = readl(®s->spisr); + n_words++; + } while (!(sr & SPISR_TX_FULL)); + + return n_words; +} + static int xilinx_spi_probe(struct udevice *bus) { struct xilinx_spi_priv *priv = dev_get_priv(bus); @@ -116,6 +137,8 @@ static int xilinx_spi_probe(struct udevice *bus) regs = priv->regs = dev_read_addr_ptr(bus); priv->fifo_depth = dev_read_u32_default(bus, "fifo-size", 0); + if (!priv->fifo_depth) + priv->fifo_depth = xilinx_spi_find_buffer_size(regs); writel(SPISSR_RESET_VALUE, ®s->srr); |