On 19/07/16 14:36, Mirza Krak wrote:
> From: Mirza Krak <mirza.krak@xxxxxxxxx>
>
> The NOR bus can be used to connect high-speed devices such as NOR flash,
> FPGAs, DSPs, CAN chips, Wi-Fi chips etc.
>
> Signed-off-by: Mirza Krak <mirza.krak@xxxxxxxxx>
> ---
> drivers/bus/Kconfig | 7 +++
> drivers/bus/Makefile | 1 +
> drivers/bus/tegra-nor.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 126 insertions(+)
> create mode 100644 drivers/bus/tegra-nor.c
>
> diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
> index 3b205e2..b74be7d8 100644
> --- a/drivers/bus/Kconfig
> +++ b/drivers/bus/Kconfig
> @@ -145,6 +145,13 @@ 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_NOR
> + tristate "Nvidia Tegra NOR flash bus driver a.k.a GMI/SNOR"
> + depends on ARCH_TEGRA_2x_SOC || ARCH_TEGRA_3x_SOC
> + depends on OF
> + help
> + Driver for NOR flash bus found on Tegra30/20 SOC`s.
It is actually present on all Tegra's and so I would drop the 30/20.
> +
> 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..46d0129 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-$(CONFIG_TEGRA_NOR) += tegra-nor.o
> obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
> obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o
> diff --git a/drivers/bus/tegra-nor.c b/drivers/bus/tegra-nor.c
> new file mode 100644
> index 0000000..1e48113
> --- /dev/null
> +++ b/drivers/bus/tegra-nor.c
> @@ -0,0 +1,118 @@
> +/*
> + * Driver for Nvidia NOR Flash bus a.k.a SNOR/GMI.
> + *
> + * 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/io.h>
> +#include <linux/mfd/syscon.h>
Is this needed?
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
Or this?
> +
> +#define TEGRA_NOR_TIMING_REG_COUNT 2
> +
> +#define TEGRA_NOR_CONFIG 0x00
> +#define TEGRA_NOR_STATUS 0x04
> +#define TEGRA_NOR_ADDR_PTR 0x08
> +#define TEGRA_NOR_AHB_ADDR_PTR 0x0c
> +#define TEGRA_NOR_TIMING0 0x10
> +#define TEGRA_NOR_TIMING1 0x14
> +#define TEGRA_NOR_MIO_CONFIG 0x18
> +#define TEGRA_NOR_MIO_TIMING 0x1c
> +#define TEGRA_NOR_DMA_CONFIG 0x20
> +#define TEGRA_NOR_CS_MUX_CONFIG 0x24
Not all of these are used. It is good to define them and I wonder if we
should add support for MIO while are at it :-)
> +
> +#define TEGRA_NOR_CONFIG_GO BIT(31)
> +
> +static const struct of_device_id nor_id_table[] = {
> + /* Tegra30 */
I don't think this comment is needed.
> + { .compatible = "nvidia,tegra30-nor", .data = NULL, },
You don't need to set data to NULL.
> + /* Tegra20 */
> + { .compatible = "nvidia,tegra20-nor", .data = NULL, },
Same here.
> +
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, nor_id_table);
> +
> +
> +static int __init nor_parse_dt(struct platform_device *pdev,
> + void __iomem *base)
> +{
> + struct device_node *of_node = pdev->dev.of_node;
> + u32 config, timing[TEGRA_NOR_TIMING_REG_COUNT];
> + int ret;
> +
> + ret = of_property_read_u32_array(of_node, "nvidia,cs-timing",
> + timing, TEGRA_NOR_TIMING_REG_COUNT);
> + if (!ret) {
> + writel(timing[0], base + TEGRA_NOR_TIMING0);
> + writel(timing[1], base + TEGRA_NOR_TIMING1);
> + }
> +
> + ret = of_property_read_u32(of_node, "nvidia,config", &config);
> + if (ret)
> + return ret;
> +
> + config |= TEGRA_NOR_CONFIG_GO;
> + writel(config, base + TEGRA_NOR_CONFIG);
> +
> + if (of_get_child_count(of_node))
> + ret = of_platform_populate(of_node,
> + of_default_bus_match_table,
> + NULL, &pdev->dev);
> +
> + return ret;
> +}
> +
> +static int __init nor_probe(struct platform_device *pdev)
> +{
I would drop the __init.
> + struct resource *res;
> + struct clk *clk;
> + void __iomem *base;
> + int ret;
> +
> + /* get the resource */
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> +
> + /* get the clock */
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk))
> + return PTR_ERR(clk);
> +
> + ret = clk_prepare_enable(clk);
> + if (ret)
> + return ret;
> +
> + /* parse the device node */
> + ret = nor_parse_dt(pdev, base);
> + if (ret) {
> + dev_err(&pdev->dev, "%s fail to create devices.\n",
> + pdev->dev.of_node->full_name);
> + clk_disable_unprepare(clk);
> + return ret;
> + }
> +
> + dev_info(&pdev->dev, "Driver registered.\n");
> + return 0;
> +}
> +
> +static struct platform_driver nor_driver = {
> + .driver = {
> + .name = "tegra-nor",
> + .of_match_table = nor_id_table,
> + },
> +};
The driver should have a remove function given that we can build as a
module.
> +module_platform_driver_probe(nor_driver, nor_probe);
I would use "tegra_nor" namespace for all the structs, functions, etc.
However, we may prefer to go with GMI and in which case tegra_gmi_probe,
etc.
Cheers
Jon
--
nvpublic
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