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linux/drivers/bus/tegra-gmi.c
Dmitry Osipenko 59caf73284 bus: tegra-gmi: Add runtime PM and OPP support 
The GMI bus on Tegra belongs to the core power domain and we're going to
enable GENPD support for the core domain. Now GMI must be resumed using
runtime PM API in order to initialize the GMI power state. Add runtime PM
and OPP support to the GMI driver.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2021-12-16 14:05:23 +01:00

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8.3 KiB
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/*
* 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/pm_runtime.h>
#include <linux/reset.h>
#include <soc/tegra/common.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)
#define TEGRA_GMI_MAX_CHIP_SELECT 8
struct tegra_gmi {
struct device *dev;
void __iomem *base;
struct clk *clk;
struct reset_control *rst;
u32 snor_config;
u32 snor_timing0;
u32 snor_timing1;
};
static int tegra_gmi_enable(struct tegra_gmi *gmi)
{
int err;
pm_runtime_enable(gmi->dev);
err = pm_runtime_resume_and_get(gmi->dev);
if (err) {
pm_runtime_disable(gmi->dev);
return err;
}
reset_control_assert(gmi->rst);
usleep_range(2000, 4000);
reset_control_deassert(gmi->rst);
writel(gmi->snor_timing0, gmi->base + TEGRA_GMI_TIMING0);
writel(gmi->snor_timing1, gmi->base + TEGRA_GMI_TIMING1);
gmi->snor_config |= TEGRA_GMI_CONFIG_GO;
writel(gmi->snor_config, gmi->base + TEGRA_GMI_CONFIG);
return 0;
}
static void tegra_gmi_disable(struct tegra_gmi *gmi)
{
u32 config;
/* stop GMI operation */
config = readl(gmi->base + TEGRA_GMI_CONFIG);
config &= ~TEGRA_GMI_CONFIG_GO;
writel(config, gmi->base + TEGRA_GMI_CONFIG);
reset_control_assert(gmi->rst);
pm_runtime_put_sync_suspend(gmi->dev);
pm_runtime_force_suspend(gmi->dev);
}
static int tegra_gmi_parse_dt(struct tegra_gmi *gmi)
{
struct device_node *child;
u32 property, ranges[4];
int err;
child = of_get_next_available_child(gmi->dev->of_node, NULL);
if (!child) {
dev_err(gmi->dev, "no child nodes found\n");
return -ENODEV;
}
/*
* 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(gmi->dev->of_node) > 1)
dev_warn(gmi->dev, "only one child device is supported.");
if (of_property_read_bool(child, "nvidia,snor-data-width-32bit"))
gmi->snor_config |= TEGRA_GMI_BUS_WIDTH_32BIT;
if (of_property_read_bool(child, "nvidia,snor-mux-mode"))
gmi->snor_config |= TEGRA_GMI_MUX_MODE;
if (of_property_read_bool(child, "nvidia,snor-rdy-active-before-data"))
gmi->snor_config |= TEGRA_GMI_RDY_BEFORE_DATA;
if (of_property_read_bool(child, "nvidia,snor-rdy-active-high"))
gmi->snor_config |= TEGRA_GMI_RDY_ACTIVE_HIGH;
if (of_property_read_bool(child, "nvidia,snor-adv-active-high"))
gmi->snor_config |= TEGRA_GMI_ADV_ACTIVE_HIGH;
if (of_property_read_bool(child, "nvidia,snor-oe-active-high"))
gmi->snor_config |= TEGRA_GMI_OE_ACTIVE_HIGH;
if (of_property_read_bool(child, "nvidia,snor-cs-active-high"))
gmi->snor_config |= TEGRA_GMI_CS_ACTIVE_HIGH;
/* Decode the CS# */
err = of_property_read_u32_array(child, "ranges", ranges, 4);
if (err < 0) {
/* Invalid binding */
if (err == -EOVERFLOW) {
dev_err(gmi->dev,
"failed to decode CS: invalid ranges length\n");
goto error_cs;
}
/*
* 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.
*/
err = of_property_read_u32(child, "reg", &property);
if (err < 0) {
dev_err(gmi->dev,
"failed to decode CS: no reg property found\n");
goto error_cs;
}
} else {
property = ranges[1];
}
/* Valid chip selects are CS0-CS7 */
if (property >= TEGRA_GMI_MAX_CHIP_SELECT) {
dev_err(gmi->dev, "invalid chip select: %d", property);
err = -EINVAL;
goto error_cs;
}
gmi->snor_config |= TEGRA_GMI_CS_SELECT(property);
/* The default values that are provided below are reset values */
if (!of_property_read_u32(child, "nvidia,snor-muxed-width", &property))
gmi->snor_timing0 |= TEGRA_GMI_MUXED_WIDTH(property);
else
gmi->snor_timing0 |= TEGRA_GMI_MUXED_WIDTH(1);
if (!of_property_read_u32(child, "nvidia,snor-hold-width", &property))
gmi->snor_timing0 |= TEGRA_GMI_HOLD_WIDTH(property);
else
gmi->snor_timing0 |= TEGRA_GMI_HOLD_WIDTH(1);
if (!of_property_read_u32(child, "nvidia,snor-adv-width", &property))
gmi->snor_timing0 |= TEGRA_GMI_ADV_WIDTH(property);
else
gmi->snor_timing0 |= TEGRA_GMI_ADV_WIDTH(1);
if (!of_property_read_u32(child, "nvidia,snor-ce-width", &property))
gmi->snor_timing0 |= TEGRA_GMI_CE_WIDTH(property);
else
gmi->snor_timing0 |= TEGRA_GMI_CE_WIDTH(4);
if (!of_property_read_u32(child, "nvidia,snor-we-width", &property))
gmi->snor_timing1 |= TEGRA_GMI_WE_WIDTH(property);
else
gmi->snor_timing1 |= TEGRA_GMI_WE_WIDTH(1);
if (!of_property_read_u32(child, "nvidia,snor-oe-width", &property))
gmi->snor_timing1 |= TEGRA_GMI_OE_WIDTH(property);
else
gmi->snor_timing1 |= TEGRA_GMI_OE_WIDTH(1);
if (!of_property_read_u32(child, "nvidia,snor-wait-width", &property))
gmi->snor_timing1 |= TEGRA_GMI_WAIT_WIDTH(property);
else
gmi->snor_timing1 |= TEGRA_GMI_WAIT_WIDTH(3);
error_cs:
of_node_put(child);
return err;
}
static int tegra_gmi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct tegra_gmi *gmi;
struct resource *res;
int err;
gmi = devm_kzalloc(dev, sizeof(*gmi), GFP_KERNEL);
if (!gmi)
return -ENOMEM;
platform_set_drvdata(pdev, gmi);
gmi->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
gmi->base = devm_ioremap_resource(dev, res);
if (IS_ERR(gmi->base))
return PTR_ERR(gmi->base);
gmi->clk = devm_clk_get(dev, "gmi");
if (IS_ERR(gmi->clk)) {
dev_err(dev, "can not get clock\n");
return PTR_ERR(gmi->clk);
}
gmi->rst = devm_reset_control_get(dev, "gmi");
if (IS_ERR(gmi->rst)) {
dev_err(dev, "can not get reset\n");
return PTR_ERR(gmi->rst);
}
err = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);
if (err)
return err;
err = tegra_gmi_parse_dt(gmi);
if (err)
return err;
err = tegra_gmi_enable(gmi);
if (err < 0)
return err;
err = of_platform_default_populate(dev->of_node, NULL, dev);
if (err < 0) {
dev_err(dev, "fail to create devices.\n");
tegra_gmi_disable(gmi);
return err;
}
return 0;
}
static int tegra_gmi_remove(struct platform_device *pdev)
{
struct tegra_gmi *gmi = platform_get_drvdata(pdev);
of_platform_depopulate(gmi->dev);
tegra_gmi_disable(gmi);
return 0;
}
static int __maybe_unused tegra_gmi_runtime_resume(struct device *dev)
{
struct tegra_gmi *gmi = dev_get_drvdata(dev);
int err;
err = clk_prepare_enable(gmi->clk);
if (err < 0) {
dev_err(gmi->dev, "failed to enable clock: %d\n", err);
return err;
}
return 0;
}
static int __maybe_unused tegra_gmi_runtime_suspend(struct device *dev)
{
struct tegra_gmi *gmi = dev_get_drvdata(dev);
clk_disable_unprepare(gmi->clk);
return 0;
}
static const struct dev_pm_ops tegra_gmi_pm = {
SET_RUNTIME_PM_OPS(tegra_gmi_runtime_suspend, tegra_gmi_runtime_resume,
NULL)
};
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,
.pm = &tegra_gmi_pm,
},
};
module_platform_driver(tegra_gmi_driver);
MODULE_AUTHOR("Mirza Krak <mirza.krak@gmail.com");
MODULE_DESCRIPTION("NVIDIA Tegra GMI Bus Driver");
MODULE_LICENSE("GPL v2");
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