Re: [PATCH v1 23/29] memory: tegra124-emc: Register as interconnect provider

Dmitry Osipenko
2019-11-19T16:58:07Z

18.11.2019 23:02, Dmitry Osipenko пишет:
> EMC now provides MC with memory bandwidth using interconnect API.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/memory/tegra/tegra124-emc.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
> index 2c73260654ba..c9478dcbeece 100644
> --- a/drivers/memory/tegra/tegra124-emc.c
> +++ b/drivers/memory/tegra/tegra124-emc.c
> @@ -25,6 +25,7 @@
> #define EMC_FBIO_CFG5 0x104
> #define EMC_FBIO_CFG5_DRAM_TYPE_MASK 0x3
> #define EMC_FBIO_CFG5_DRAM_TYPE_SHIFT 0
> +#define EMC_FBIO_CFG5_DRAM_WIDTH_X64 BIT(4)
>
> #define EMC_INTSTATUS 0x0
> #define EMC_INTSTATUS_CLKCHANGE_COMPLETE BIT(4)
> @@ -1080,11 +1081,28 @@ static void emc_debugfs_init(struct device *dev, struct tegra_emc *emc)
> dev_err(dev, "failed to create debugfs entry\n");
> }
>
> +static unsigned int emc_dram_data_bus_width_bytes(struct tegra_emc *emc)
> +{
> + unsigned int bus_width;
> + u32 emc_cfg;
> +
> + emc_cfg = readl_relaxed(emc->regs + EMC_FBIO_CFG5);
> + if (emc_cfg & EMC_FBIO_CFG5_DRAM_WIDTH_X64)
> + bus_width = 64;
> + else
> + bus_width = 32;

Looks like I got a bit confused while was looking at TRMs before, seems
this width is unrelated to the EMC channel at all. I'll try to revisit
this again.

> + dev_info(emc->dev, "DRAM data-bus width: %ubit\n", bus_width);
> +
> + return bus_width / 8;
> +}
> +
> static int tegra_emc_probe(struct platform_device *pdev)
> {
> struct platform_device *mc;
> struct device_node *np;
> struct tegra_emc *emc;
> + unsigned int bus_width;
> u32 ram_code;
> int err;
>
> @@ -1146,6 +1164,12 @@ static int tegra_emc_probe(struct platform_device *pdev)
> if (IS_ENABLED(CONFIG_DEBUG_FS))
> emc_debugfs_init(&pdev->dev, emc);
>
> + bus_width = emc_dram_data_bus_width_bytes(emc);
> +
> + err = tegra_icc_emc_setup_interconnect(&pdev->dev, bus_width);
> + if (err)
> + dev_err(&pdev->dev, "failed to initialize ICC: %d\n", err);
> +
> return 0;
> };
>
>