On 27/10/16 15:01, Mirza Krak wrote:
From: Mirza Krak <mirza.krak@xxxxxxxxx> The Generic Memory Interface bus can be used to connect high-speed devices such as NOR flash, FPGAs, DSPs... Signed-off-by: Mirza Krak <mirza.krak@xxxxxxxxx> Tested-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx> Tested-on: Colibri T20/T30 on EvalBoard V3.x and GMI-Memory Board --- Changes in v2: - Fixed some checkpatch errors - Re-ordered probe to get rid of local variables - Moved of_platform_default_populate call to the end of probe - Use the timing and configuration properties from the child device - Added warning if more then 1 child device exist Changes in v3: - added helper function to disable the controller which is used in remove and on error. - Added logic to parse CS# from "ranges" property with fallback to "reg" property drivers/bus/Kconfig | 8 ++ drivers/bus/Makefile | 1 + drivers/bus/tegra-gmi.c | 267 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 276 insertions(+) create mode 100644 drivers/bus/tegra-gmi.c diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig index 4ed7d26..2e75a7f 100644 --- a/drivers/bus/Kconfig +++ b/drivers/bus/Kconfig @@ -141,6 +141,14 @@ config TEGRA_ACONNECT Driver for the Tegra ACONNECT bus which is used to interface with the devices inside the Audio Processing Engine (APE) for Tegra210. +config TEGRA_GMI + tristate "Tegra Generic Memory Interface bus driver" + depends on ARCH_TEGRA + help + Driver for the Tegra Generic Memory Interface bus which can be used + to attach devices such as NOR, UART, FPGA and more. + +
Nit-pick ... only one additional line above is needed to be consistent with the rest of the file.
config UNIPHIER_SYSTEM_BUS tristate "UniPhier System Bus driver" depends on ARCH_UNIPHIER && OF diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile index ac84cc4..34e2bab 100644 --- a/drivers/bus/Makefile +++ b/drivers/bus/Makefile @@ -18,5 +18,6 @@ obj-$(CONFIG_OMAP_OCP2SCP) += omap-ocp2scp.o obj-$(CONFIG_SUNXI_RSB) += sunxi-rsb.o obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o obj-$(CONFIG_TEGRA_ACONNECT) += tegra-aconnect.o +obj-$(CONFIG_TEGRA_GMI) += tegra-gmi.o obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o diff --git a/drivers/bus/tegra-gmi.c b/drivers/bus/tegra-gmi.c new file mode 100644 index 0000000..dd9623e --- /dev/null +++ b/drivers/bus/tegra-gmi.c @@ -0,0 +1,267 @@ +/* + * Driver for NVIDIA Generic Memory Interface + * + * Copyright (C) 2016 Host Mobility AB. All rights reserved. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/reset.h> + +#define TEGRA_GMI_CONFIG 0x00 +#define TEGRA_GMI_CONFIG_GO BIT(31) +#define TEGRA_GMI_BUS_WIDTH_32BIT BIT(30) +#define TEGRA_GMI_MUX_MODE BIT(28) +#define TEGRA_GMI_RDY_BEFORE_DATA BIT(24) +#define TEGRA_GMI_RDY_ACTIVE_HIGH BIT(23) +#define TEGRA_GMI_ADV_ACTIVE_HIGH BIT(22) +#define TEGRA_GMI_OE_ACTIVE_HIGH BIT(21) +#define TEGRA_GMI_CS_ACTIVE_HIGH BIT(20) +#define TEGRA_GMI_CS_SELECT(x) ((x & 0x7) << 4) + +#define TEGRA_GMI_TIMING0 0x10 +#define TEGRA_GMI_MUXED_WIDTH(x) ((x & 0xf) << 12) +#define TEGRA_GMI_HOLD_WIDTH(x) ((x & 0xf) << 8) +#define TEGRA_GMI_ADV_WIDTH(x) ((x & 0xf) << 4) +#define TEGRA_GMI_CE_WIDTH(x) (x & 0xf) + +#define TEGRA_GMI_TIMING1 0x14 +#define TEGRA_GMI_WE_WIDTH(x) ((x & 0xff) << 16) +#define TEGRA_GMI_OE_WIDTH(x) ((x & 0xff) << 8) +#define TEGRA_GMI_WAIT_WIDTH(x) (x & 0xff) + +struct tegra_gmi_priv { + void __iomem *base; + struct reset_control *rst; + struct clk *clk; + + u32 snor_config; + u32 snor_timing0; + u32 snor_timing1; +}; + +static void tegra_gmi_disable(struct tegra_gmi_priv *priv) +{ + u32 config; + + /* stop GMI operation */ + config = readl(priv->base + TEGRA_GMI_CONFIG); + config &= ~TEGRA_GMI_CONFIG_GO; + writel(config, priv->base + TEGRA_GMI_CONFIG); + + reset_control_assert(priv->rst); + clk_disable_unprepare(priv->clk); +} + +static void tegra_gmi_init(struct device *dev, struct tegra_gmi_priv *priv) +{ + writel(priv->snor_timing0, priv->base + TEGRA_GMI_TIMING0); + writel(priv->snor_timing1, priv->base + TEGRA_GMI_TIMING1); + + priv->snor_config |= TEGRA_GMI_CONFIG_GO; + writel(priv->snor_config, priv->base + TEGRA_GMI_CONFIG); +} + +static int tegra_gmi_parse_dt(struct device *dev, struct tegra_gmi_priv *priv) +{ + struct device_node *child = of_get_next_available_child(dev->of_node, + NULL); + u32 property, ranges[4]; + int ret; + + if (!child) { + dev_warn(dev, "no child nodes found\n"); + return 0;
Don't we want to return an error here? Otherwise, we will call tegra_gmi_init() with an invalid configuration.
+ } + + /* + * We currently only support one child device due to lack of + * chip-select address decoding. Which means that we only have one + * chip-select line from the GMI controller. + */ + if (of_get_child_count(dev->of_node) > 1) + dev_warn(dev, "only one child device is supported."); + + if (of_property_read_bool(child, "nvidia,snor-data-width-32bit")) + priv->snor_config |= TEGRA_GMI_BUS_WIDTH_32BIT; + + if (of_property_read_bool(child, "nvidia,snor-mux-mode")) + priv->snor_config |= TEGRA_GMI_MUX_MODE; + + if (of_property_read_bool(child, "nvidia,snor-rdy-active-before-data")) + priv->snor_config |= TEGRA_GMI_RDY_BEFORE_DATA; + + if (of_property_read_bool(child, "nvidia,snor-rdy-inv")) + priv->snor_config |= TEGRA_GMI_RDY_ACTIVE_HIGH; + + if (of_property_read_bool(child, "nvidia,snor-adv-inv")) + priv->snor_config |= TEGRA_GMI_ADV_ACTIVE_HIGH; + + if (of_property_read_bool(child, "nvidia,snor-oe-inv")) + priv->snor_config |= TEGRA_GMI_OE_ACTIVE_HIGH; + + if (of_property_read_bool(child, "nvidia,snor-cs-inv")) + priv->snor_config |= TEGRA_GMI_CS_ACTIVE_HIGH; + + /* Decode the CS# */ + ret = of_property_read_u32_array(child, "ranges", ranges, 4); + if (ret < 0) { + /* Invalid binding */ + if (ret == -EOVERFLOW) { + dev_err(dev, "invalid ranges length\n"); + goto error_cs_decode; + } + + /* + * If we reach here it means that the child node has an empty + * ranges or it does not exist at all. Attempt to decode the + * CS# from the reg property instead. + */ + ret = of_property_read_u32(child, "reg", &property); + if (ret < 0) { + dev_err(dev, "no reg property found\n"); + goto error_cs_decode; + } + } else { + property = ranges[1]; + } + + priv->snor_config |= TEGRA_GMI_CS_SELECT(property);
Should we make sure the CS is a valid value before setting?
+ + /* The default values that are provided below are reset values */ + if (!of_property_read_u32(child, "nvidia,snor-muxed-width", &property)) + priv->snor_timing0 |= TEGRA_GMI_MUXED_WIDTH(property); + else + priv->snor_timing0 |= TEGRA_GMI_MUXED_WIDTH(1); + + if (!of_property_read_u32(child, "nvidia,snor-hold-width", &property)) + priv->snor_timing0 |= TEGRA_GMI_HOLD_WIDTH(property); + else + priv->snor_timing0 |= TEGRA_GMI_HOLD_WIDTH(1); + + if (!of_property_read_u32(child, "nvidia,snor-adv-width", &property)) + priv->snor_timing0 |= TEGRA_GMI_ADV_WIDTH(property); + else + priv->snor_timing0 |= TEGRA_GMI_ADV_WIDTH(1); + + if (!of_property_read_u32(child, "nvidia,snor-ce-width", &property)) + priv->snor_timing0 |= TEGRA_GMI_CE_WIDTH(property); + else + priv->snor_timing0 |= TEGRA_GMI_CE_WIDTH(4); + + if (!of_property_read_u32(child, "nvidia,snor-we-width", &property)) + priv->snor_timing1 |= TEGRA_GMI_WE_WIDTH(property); + else + priv->snor_timing1 |= TEGRA_GMI_WE_WIDTH(1); + + if (!of_property_read_u32(child, "nvidia,snor-oe-width", &property)) + priv->snor_timing1 |= TEGRA_GMI_OE_WIDTH(property); + else + priv->snor_timing1 |= TEGRA_GMI_OE_WIDTH(1); + + if (!of_property_read_u32(child, "nvidia,snor-wait-width", &property)) + priv->snor_timing1 |= TEGRA_GMI_WAIT_WIDTH(property); + else + priv->snor_timing1 |= TEGRA_GMI_WAIT_WIDTH(3); + +error_cs_decode: + if (ret < 0) + dev_err(dev, "failed to decode chip-select number\n");
Nit do we need another error message here? Can we add the "failed to decode CS" part the earlier message?
+ + of_node_put(child); + return ret; +} + +static int tegra_gmi_probe(struct platform_device *pdev) +{ + struct resource *res; + struct device *dev = &pdev->dev; + struct tegra_gmi_priv *priv; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->base = devm_ioremap_resource(dev, res); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->clk = devm_clk_get(dev, "gmi"); + if (IS_ERR(priv->clk)) { + dev_err(dev, "can not get clock\n"); + return PTR_ERR(priv->clk); + } + + priv->rst = devm_reset_control_get(dev, "gmi"); + if (IS_ERR(priv->rst)) { + dev_err(dev, "can not get reset\n"); + return PTR_ERR(priv->rst); + } + + ret = tegra_gmi_parse_dt(dev, priv); + if (ret) + return ret; + + ret = clk_prepare_enable(priv->clk); + if (ret) { + dev_err(dev, "fail to enable clock.\n"); + return ret; + } + + reset_control_assert(priv->rst); + udelay(2); + reset_control_deassert(priv->rst); + + tegra_gmi_init(dev, priv); + + ret = of_platform_default_populate(dev->of_node, NULL, dev); + if (ret < 0) { + dev_err(dev, "fail to create devices.\n"); + tegra_gmi_disable(priv); + return ret; + } + + dev_set_drvdata(dev, priv); + + return 0; +} + +static int tegra_gmi_remove(struct platform_device *pdev) +{ + struct tegra_gmi_priv *priv = dev_get_drvdata(&pdev->dev); + + of_platform_depopulate(&pdev->dev); + + tegra_gmi_disable(priv); + + return 0; +} + +static const struct of_device_id tegra_gmi_id_table[] = { + { .compatible = "nvidia,tegra20-gmi", }, + { .compatible = "nvidia,tegra30-gmi", }, + { } +}; +MODULE_DEVICE_TABLE(of, tegra_gmi_id_table); + +static struct platform_driver tegra_gmi_driver = { + .probe = tegra_gmi_probe, + .remove = tegra_gmi_remove, + .driver = { + .name = "tegra-gmi", + .of_match_table = tegra_gmi_id_table, + }, +}; +module_platform_driver(tegra_gmi_driver); + +MODULE_AUTHOR("Mirza Krak <mirza.krak@xxxxxxxxx"); +MODULE_DESCRIPTION("NVIDIA Tegra GMI Bus Driver"); +MODULE_LICENSE("GPL v2"); -- 2.1.4
Cheers Jon -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html