Re: [PATCH v2 2/3] mtd: spi-nor: cadence-quadspi: disable DMA and DAC for Intel LGM
From: Ramuthevar, Vadivel MuruganX
Date: Mon Sep 09 2019 - 03:33:05 EST
Hi Vignesh,
Thank you so much for the review comments and your time.
On 9/9/2019 2:05 PM, Vignesh Raghavendra wrote:
Hi,
On 27/08/19 9:28 AM, Ramuthevar,Vadivel MuruganX wrote:
From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
on Intel's Lightning Mountain(LGM) SoCs QSPI controller do not use
Direct Memory Access(DMA) and Direct Access Controller(DAC).
This patch introduces to properly disable the DMA and DAC
for data transfer instead it uses indirect data transfer.
Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
---
drivers/mtd/spi-nor/Kconfig | 2 +-
drivers/mtd/spi-nor/cadence-quadspi.c | 21 ++++++++++++++++++---
2 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 6de83277ce8b..ba2e372ae514 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -34,7 +34,7 @@ config SPI_ASPEED_SMC
config SPI_CADENCE_QUADSPI
tristate "Cadence Quad SPI controller"
- depends on OF && (ARM || ARM64 || COMPILE_TEST)
+ depends on OF && (ARM || ARM64 || COMPILE_TEST || X86)
help
Enable support for the Cadence Quad SPI Flash controller.
diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 67f15a1f16fd..69fa13e95110 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -517,12 +517,16 @@ static int cqspi_indirect_read_execute(struct spi_nor *nor, u8 *rxbuf,
struct cqspi_st *cqspi = f_pdata->cqspi;
void __iomem *reg_base = cqspi->iobase;
void __iomem *ahb_base = cqspi->ahb_base;
+ u32 trigger_address = cqspi->trigger_address;
unsigned int remaining = n_rx;
unsigned int mod_bytes = n_rx % 4;
unsigned int bytes_to_read = 0;
u8 *rxbuf_end = rxbuf + n_rx;
int ret = 0;
+ if (!f_pdata->use_direct_mode)
+ writel(trigger_address, reg_base + CQSPI_REG_INDIRECTTRIGGER);
+
Again, as I pointed out previously, this should not be needed.
cqspi_controller_init() already does above configuration and no need to
touch this register on every read.
Agreed!, drop this one.
writel(from_addr, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR);
writel(remaining, reg_base + CQSPI_REG_INDIRECTRDBYTES);
@@ -609,6 +613,14 @@ static int cqspi_write_setup(struct spi_nor *nor)
struct cqspi_st *cqspi = f_pdata->cqspi;
void __iomem *reg_base = cqspi->iobase;
+ /* Disable the DMA and direct access controller */
+ if (!f_pdata->use_direct_mode) {
+ reg = readl(reg_base + CQSPI_REG_CONFIG);
+ reg &= ~CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
+ reg &= ~CQSPI_REG_CONFIG_DMA_MASK;
+ writel(reg, reg_base + CQSPI_REG_CONFIG);
+ }
+
You did not respond to my previous comment. Why would you need to clear
CQSPI_REG_CONFIG_DMA_MASK field, if reset default is 0 anyway?
while testing on the real setup it is not working for me, double confirm
and drop it.
/* Set opcode. */
reg = nor->program_opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
writel(reg, reg_base + CQSPI_REG_WR_INSTR);
@@ -1171,7 +1183,8 @@ static int cqspi_of_get_pdata(struct platform_device *pdev)
return -ENXIO;
}
- cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
+ if (!of_device_is_compatible(np, "intel,lgm-qspi"))
+ cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
If you don't want to use this property, then just drop it from your DT.
Don't override it in the driver based on compatible.
Sure.
return 0;
}
@@ -1301,7 +1314,8 @@ static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np)
f_pdata->registered = true;
if (mtd->size <= cqspi->ahb_size) {
- f_pdata->use_direct_mode = true;
+ f_pdata->use_direct_mode =
+ !(of_device_is_compatible(np, "intel,lgm-qspi"));
Looks like, you haven't followed any of my advice. Please add a quirk
flag to disable DAC mode. Something like:
Sorry, on real setup kernel got crash if we add quirks, so that is the
reason I started using DT compatible to
avoid crashing and also don't want disturb the existing functionalities.
Let me check once again.
Thank you so much for your valuable comments.
#define CQSPI_DISABLE_DAC_MODE BIT(1)
static const struct cqspi_driver_platdata intel_lgm_qspi = {
.hwcaps_mask = CQSPI_BASE_HWCAPS_MASK,
.quirks = CQSPI_DISABLE_DAC_MODE,
};
static const struct of_device_id cqspi_dt_ids[] = {
...
{
.compatible = "intel,lgm-qspi",
.data = &intel_lgm_qspi,
},
...
};
Then in cqspi_setup_flash(),
if (mtd->size <= cqspi->ahb_size &&
!ddata->quirks & CQSPI_DISABLE_DAC_MODE) {
f_pdata->use_direct_mode = true;
...
}
dev_dbg(nor->dev, "using direct mode for %s\n",
mtd->name);
@@ -1347,7 +1361,7 @@ static int cqspi_probe(struct platform_device *pdev)
}
/* Obtain QSPI clock. */
- cqspi->clk = devm_clk_get(dev, NULL);
+ cqspi->clk = devm_clk_get(dev, "qspi");
This will break DT backward compatibility. Existing DTs don't have
clock-names = "qspi". Hence, this code will error out.
What I meant in the previous mail was: if device does not have multiple
clk inputs then there is no need for clock-names and there is no need to
touch this part of code.
cqspi->clk = devm_clk_get(dev, NULL);
This should just work fine even on your board. So drop this hunk.
Sure, I will drop it.
if (IS_ERR(cqspi->clk)) {
dev_err(dev, "Cannot claim QSPI clock.\n");
return PTR_ERR(cqspi->clk);
@@ -1369,6 +1383,7 @@ static int cqspi_probe(struct platform_device *pdev)
return PTR_ERR(cqspi->ahb_base);
}
cqspi->mmap_phys_base = (dma_addr_t)res_ahb->start;
+ cqspi->trigger_address = res_ahb->start;
Nope, this is not needed. See:
https://elixir.bootlin.com/linux/v5.3-rc6/source/drivers/mtd/spi-nor/cadence-quadspi.c#L1168
Populate the trigger-address using cdns,trigger-address property in DT
Agreed!, fix it in the next version.
Best Regards
vadivel
cqspi->ahb_size = resource_size(res_ahb);
init_completion(&cqspi->transfer_complete);