Create a new driver for the da8xx DDR2/mDDR controller and implement support for writing to the Peripheral Bus Burst Priority Register.
Signed-off-by: Bartosz Golaszewski bgolaszewski@baylibre.com --- .../memory-controllers/ti-da8xx-ddrctl.txt | 20 +++ drivers/memory/Kconfig | 8 + drivers/memory/Makefile | 1 + drivers/memory/da8xx-ddrctl.c | 175 +++++++++++++++++++++ 4 files changed, 204 insertions(+) create mode 100644 Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt create mode 100644 drivers/memory/da8xx-ddrctl.c
diff --git a/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt b/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt new file mode 100644 index 0000000..7e271dd --- /dev/null +++ b/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt @@ -0,0 +1,20 @@ +* Device tree bindings for Texas Instruments da8xx DDR2/mDDR memory controller + +The DDR2/mDDR memory controller present on Texas Instruments da8xx SoCs features +a set of registers which allow to tweak the controller's behavior. + +Documentation: +OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf + +Required properties: + +- compatible: "ti,da850-ddr-controller" - for da850 SoC based boards +- reg: a tuple containing the base address of the memory + controller and the size of the memory area to map + +Example for da850 shown below. + +ddrctl { + compatible = "ti,da850-ddr-controller"; + reg = <0xB0000000 0x100>; +}; diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig index 4b4c0c3..ec80e35 100644 --- a/drivers/memory/Kconfig +++ b/drivers/memory/Kconfig @@ -134,6 +134,14 @@ config MTK_SMI mainly help enable/disable iommu and control the power domain and clocks for each local arbiter.
+config DA8XX_DDRCTL + bool "Texas Instruments da8xx DDR2/mDDR driver" + depends on ARCH_DAVINCI_DA8XX + help + This driver is for the DDR2/mDDR Memory Controller present on + Texas Instruments da8xx SoCs. It's used to tweak various memory + controller configuration options. + source "drivers/memory/samsung/Kconfig" source "drivers/memory/tegra/Kconfig"
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile index b20ae38..e88097fb 100644 --- a/drivers/memory/Makefile +++ b/drivers/memory/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o obj-$(CONFIG_JZ4780_NEMC) += jz4780-nemc.o obj-$(CONFIG_MTK_SMI) += mtk-smi.o +obj-$(CONFIG_DA8XX_DDRCTL) += da8xx-ddrctl.o
obj-$(CONFIG_SAMSUNG_MC) += samsung/ obj-$(CONFIG_TEGRA_MC) += tegra/ diff --git a/drivers/memory/da8xx-ddrctl.c b/drivers/memory/da8xx-ddrctl.c new file mode 100644 index 0000000..900e131 --- /dev/null +++ b/drivers/memory/da8xx-ddrctl.c @@ -0,0 +1,175 @@ +/* + * TI da8xx DDR2/mDDR controller driver + * + * Copyright (C) 2016 BayLibre SAS + * + * Author: + * Bartosz Golaszewski bgolaszewski@baylibre.com + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_fdt.h> +#include <linux/platform_device.h> +#include <linux/io.h> + +/* + * REVISIT: Linux doesn't have a good framework for the kind of performance + * knobs this driver controls. We can't use device tree properties as it deals + * with hardware configuration rather than description. We also don't want to + * commit to maintaining some random sysfs attributes. + * + * For now we just hardcode the register values for the boards that need + * some changes (as is the case for the LCD controller on da850-lcdk - the + * first board we support here). When linux gets an appropriate framework, + * we'll easily convert the driver to it. + */ + +struct da8xx_ddrctl_config_knob { + const char *name; + u32 reg; + u32 mask; + u32 shift; +}; + +static const struct da8xx_ddrctl_config_knob da8xx_ddrctl_knobs[] = { + { + .name = "da850-pbbpr", + .reg = 0x20, + .mask = 0xffffff00, + .shift = 0, + }, +}; + +struct da8xx_ddrctl_setting { + const char *name; + u32 val; +}; + +struct da8xx_ddrctl_board_settings { + const char *board; + const struct da8xx_ddrctl_setting *settings; +}; + +static const struct da8xx_ddrctl_setting da850_lcdk_ddrctl_settings[] = { + { + .name = "da850-pbbpr", + .val = 0x20, + }, + { } +}; + +static const struct da8xx_ddrctl_board_settings da8xx_ddrctl_board_confs[] = { + { + .board = "ti,da850-lcdk", + .settings = da850_lcdk_ddrctl_settings, + }, +}; + +static const struct da8xx_ddrctl_config_knob * +da8xx_ddrctl_match_knob(const struct da8xx_ddrctl_setting *setting) +{ + const struct da8xx_ddrctl_config_knob *knob; + int i; + + for (i = 0; i < ARRAY_SIZE(da8xx_ddrctl_knobs); i++) { + knob = &da8xx_ddrctl_knobs[i]; + + if (strcmp(knob->name, setting->name) == 0) + return knob; + } + + return NULL; +} + +static const struct da8xx_ddrctl_setting *da8xx_ddrctl_get_board_settings(void) +{ + const struct da8xx_ddrctl_board_settings *board_settings; + int i; + + for (i = 0; i < ARRAY_SIZE(da8xx_ddrctl_board_confs); i++) { + board_settings = &da8xx_ddrctl_board_confs[i]; + + if (of_machine_is_compatible(board_settings->board)) + return board_settings->settings; + } + + return NULL; +} + +static int da8xx_ddrctl_probe(struct platform_device *pdev) +{ + const struct da8xx_ddrctl_config_knob *knob; + const struct da8xx_ddrctl_setting *setting; + struct device_node *node; + struct resource *res; + void __iomem *ddrctl; + struct device *dev; + u32 reg; + + dev = &pdev->dev; + node = dev->of_node; + + setting = da8xx_ddrctl_get_board_settings(); + if (!setting) { + dev_err(dev, "no settings for board '%s'\n", + of_flat_dt_get_machine_name()); + return -EINVAL; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + ddrctl = devm_ioremap_resource(dev, res); + if (IS_ERR(ddrctl)) { + dev_err(dev, "unable to map memory controller registers\n"); + return PTR_ERR(ddrctl); + } + + for (; setting->name; setting++) { + knob = da8xx_ddrctl_match_knob(setting); + if (!knob) { + dev_warn(dev, + "no such config option: %s\n", setting->name); + continue; + } + + if (knob->reg > (res->end - res->start - sizeof(u32))) { + dev_warn(dev, + "register offset of '%s' exceeds mapped memory size\n", + knob->name); + continue; + } + + reg = __raw_readl(ddrctl + knob->reg); + reg &= knob->mask; + reg |= setting->val << knob->shift; + + dev_dbg(dev, "writing 0x%08x to %s\n", reg, setting->name); + + __raw_writel(reg, ddrctl + knob->reg); + } + + return 0; +} + +static const struct of_device_id da8xx_ddrctl_of_match[] = { + { .compatible = "ti,da850-ddr-controller", }, + { }, +}; + +static struct platform_driver da8xx_ddrctl_driver = { + .probe = da8xx_ddrctl_probe, + .driver = { + .name = "da850-ddr-controller", + .of_match_table = da8xx_ddrctl_of_match, + }, +}; +module_platform_driver(da8xx_ddrctl_driver); + +MODULE_AUTHOR("Bartosz Golaszewski bgolaszewski@baylibre.com"); +MODULE_DESCRIPTION("TI da8xx DDR2/mDDR controller driver"); +MODULE_LICENSE("GPL v2");