[PATCH v12 1/5] memory: tegra124-emc: Make driver modular

Add modularization support to the Tegra124 EMC driver, which now can be compiled as a loadable kernel module.

Note that EMC clock must be registered at clk-init time, otherwise PLLM will be disabled as unused clock at boot time if EMC driver is compiled as a module. Hence add a prepare/complete callbacks. similarly to what is done for the Tegra20/30 EMC drivers.

Tested-by: Nicolas Chauvet kwizart@gmail.com Signed-off-by: Dmitry Osipenko digetx@gmail.com --- drivers/clk/tegra/Kconfig | 3 ++ drivers/clk/tegra/Makefile | 2 +- drivers/clk/tegra/clk-tegra124-emc.c | 41 ++++++++++++++++++++++++---- drivers/clk/tegra/clk-tegra124.c | 26 ++++++++++++++++-- drivers/clk/tegra/clk.h | 18 ++++++++---- drivers/memory/tegra/Kconfig | 3 +- drivers/memory/tegra/tegra124-emc.c | 31 ++++++++++++++------- include/linux/clk/tegra.h | 8 ++++++ include/soc/tegra/emc.h | 16 ----------- 9 files changed, 106 insertions(+), 42 deletions(-) delete mode 100644 include/soc/tegra/emc.h

diff --git a/drivers/clk/tegra/Kconfig b/drivers/clk/tegra/Kconfig index deaa4605824c..90df619dc087 100644 --- a/drivers/clk/tegra/Kconfig +++ b/drivers/clk/tegra/Kconfig @@ -7,3 +7,6 @@ config TEGRA_CLK_DFLL depends on ARCH_TEGRA_124_SOC || ARCH_TEGRA_210_SOC select PM_OPP def_bool y + +config TEGRA124_CLK_EMC + bool diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile index eec2313fd37e..7b1816856eb5 100644 --- a/drivers/clk/tegra/Makefile +++ b/drivers/clk/tegra/Makefile @@ -22,7 +22,7 @@ obj-$(CONFIG_ARCH_TEGRA_3x_SOC) += clk-tegra20-emc.o obj-$(CONFIG_ARCH_TEGRA_114_SOC) += clk-tegra114.o obj-$(CONFIG_ARCH_TEGRA_124_SOC) += clk-tegra124.o obj-$(CONFIG_TEGRA_CLK_DFLL) += clk-tegra124-dfll-fcpu.o -obj-$(CONFIG_TEGRA124_EMC) += clk-tegra124-emc.o +obj-$(CONFIG_TEGRA124_CLK_EMC) += clk-tegra124-emc.o obj-$(CONFIG_ARCH_TEGRA_132_SOC) += clk-tegra124.o obj-y += cvb.o obj-$(CONFIG_ARCH_TEGRA_210_SOC) += clk-tegra210.o diff --git a/drivers/clk/tegra/clk-tegra124-emc.c b/drivers/clk/tegra/clk-tegra124-emc.c index 745f9faa98d8..bdf6f4a51617 100644 --- a/drivers/clk/tegra/clk-tegra124-emc.c +++ b/drivers/clk/tegra/clk-tegra124-emc.c @@ -11,7 +11,9 @@ #include <linux/clk-provider.h> #include <linux/clk.h> #include <linux/clkdev.h> +#include <linux/clk/tegra.h> #include <linux/delay.h> +#include <linux/export.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of_address.h> @@ -21,7 +23,6 @@ #include <linux/string.h>

#include <soc/tegra/fuse.h> -#include <soc/tegra/emc.h>

#include "clk.h"

@@ -80,6 +81,9 @@ struct tegra_clk_emc { int num_timings; struct emc_timing *timings; spinlock_t *lock; + + tegra124_emc_prepare_timing_change_cb *prepare_timing_change; + tegra124_emc_complete_timing_change_cb *complete_timing_change; };

/* Common clock framework callback implementations */ @@ -176,6 +180,9 @@ static struct tegra_emc *emc_ensure_emc_driver(struct tegra_clk_emc *tegra) if (tegra->emc) return tegra->emc;

+ if (!tegra->prepare_timing_change || !tegra->complete_timing_change) + return NULL; + if (!tegra->emc_node) return NULL;

@@ -241,7 +248,7 @@ static int emc_set_timing(struct tegra_clk_emc *tegra,

div = timing->parent_rate / (timing->rate / 2) - 2;

- err = tegra_emc_prepare_timing_change(emc, timing->rate); + err = tegra->prepare_timing_change(emc, timing->rate); if (err) return err;

@@ -259,7 +266,7 @@ static int emc_set_timing(struct tegra_clk_emc *tegra,

spin_unlock_irqrestore(tegra->lock, flags);

- tegra_emc_complete_timing_change(emc, timing->rate); + tegra->complete_timing_change(emc, timing->rate);

clk_hw_reparent(&tegra->hw, __clk_get_hw(timing->parent)); clk_disable_unprepare(tegra->prev_parent); @@ -473,8 +480,8 @@ static const struct clk_ops tegra_clk_emc_ops = { .get_parent = emc_get_parent, };

-struct clk *tegra_clk_register_emc(void __iomem *base, struct device_node *np, - spinlock_t *lock) +struct clk *tegra124_clk_register_emc(void __iomem *base, struct device_node *np, + spinlock_t *lock) { struct tegra_clk_emc *tegra; struct clk_init_data init; @@ -538,3 +545,27 @@ struct clk *tegra_clk_register_emc(void __iomem *base, struct device_node *np,

return clk; }; + +void tegra124_clk_set_emc_callbacks(tegra124_emc_prepare_timing_change_cb *prep_cb, + tegra124_emc_complete_timing_change_cb *complete_cb) +{ + struct clk *clk = __clk_lookup("emc"); + struct tegra_clk_emc *tegra; + struct clk_hw *hw; + + if (clk) { + hw = __clk_get_hw(clk); + tegra = container_of(hw, struct tegra_clk_emc, hw); + + tegra->prepare_timing_change = prep_cb; + tegra->complete_timing_change = complete_cb; + } +} +EXPORT_SYMBOL_GPL(tegra124_clk_set_emc_callbacks); + +bool tegra124_clk_emc_driver_available(struct clk_hw *hw) +{ + struct tegra_clk_emc *tegra = container_of(hw, struct tegra_clk_emc, hw); + + return tegra->prepare_timing_change && tegra->complete_timing_change; +} diff --git a/drivers/clk/tegra/clk-tegra124.c b/drivers/clk/tegra/clk-tegra124.c index e931319dcc9d..934520aab6e3 100644 --- a/drivers/clk/tegra/clk-tegra124.c +++ b/drivers/clk/tegra/clk-tegra124.c @@ -1500,6 +1500,26 @@ static void __init tegra124_132_clock_init_pre(struct device_node *np) writel(plld_base, clk_base + PLLD_BASE); }

+static struct clk *tegra124_clk_src_onecell_get(struct of_phandle_args *clkspec, + void *data) +{ + struct clk_hw *hw; + struct clk *clk; + + clk = of_clk_src_onecell_get(clkspec, data); + if (IS_ERR(clk)) + return clk; + + hw = __clk_get_hw(clk); + + if (clkspec->args[0] == TEGRA124_CLK_EMC) { + if (!tegra124_clk_emc_driver_available(hw)) + return ERR_PTR(-EPROBE_DEFER); + } + + return clk; +} + /** * tegra124_132_clock_init_post - clock initialization postamble for T124/T132 * @np: struct device_node * of the DT node for the SoC CAR IP block @@ -1516,10 +1536,10 @@ static void __init tegra124_132_clock_init_post(struct device_node *np) &pll_x_params); tegra_init_special_resets(1, tegra124_reset_assert, tegra124_reset_deassert); - tegra_add_of_provider(np, of_clk_src_onecell_get); + tegra_add_of_provider(np, tegra124_clk_src_onecell_get);

- clks[TEGRA124_CLK_EMC] = tegra_clk_register_emc(clk_base, np, - &emc_lock); + clks[TEGRA124_CLK_EMC] = tegra124_clk_register_emc(clk_base, np, + &emc_lock);

tegra_register_devclks(devclks, ARRAY_SIZE(devclks));

diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h index 6b565f6b5f66..c3e36b5dcc75 100644 --- a/drivers/clk/tegra/clk.h +++ b/drivers/clk/tegra/clk.h @@ -881,16 +881,22 @@ void tegra_super_clk_gen5_init(void __iomem *clk_base, void __iomem *pmc_base, struct tegra_clk *tegra_clks, struct tegra_clk_pll_params *pll_params);

-#ifdef CONFIG_TEGRA124_EMC -struct clk *tegra_clk_register_emc(void __iomem *base, struct device_node *np, - spinlock_t *lock); +#ifdef CONFIG_TEGRA124_CLK_EMC +struct clk *tegra124_clk_register_emc(void __iomem *base, struct device_node *np, + spinlock_t *lock); +bool tegra124_clk_emc_driver_available(struct clk_hw *emc_hw); #else -static inline struct clk *tegra_clk_register_emc(void __iomem *base, - struct device_node *np, - spinlock_t *lock) +static inline struct clk * +tegra124_clk_register_emc(void __iomem *base, struct device_node *np, + spinlock_t *lock) { return NULL; } + +static inline bool tegra124_clk_emc_driver_available(struct clk_hw *emc_hw) +{ + return false; +} #endif

void tegra114_clock_tune_cpu_trimmers_high(void); diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig index ca7077a06f4c..f5b451403c58 100644 --- a/drivers/memory/tegra/Kconfig +++ b/drivers/memory/tegra/Kconfig @@ -32,9 +32,10 @@ config TEGRA30_EMC external memory.

config TEGRA124_EMC - bool "NVIDIA Tegra124 External Memory Controller driver" + tristate "NVIDIA Tegra124 External Memory Controller driver" default y depends on TEGRA_MC && ARCH_TEGRA_124_SOC + select TEGRA124_CLK_EMC help This driver is for the External Memory Controller (EMC) found on Tegra124 chips. The EMC controls the external DRAM on the board. diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c index ee8ee39e98ed..edfbf6d6d357 100644 --- a/drivers/memory/tegra/tegra124-emc.c +++ b/drivers/memory/tegra/tegra124-emc.c @@ -9,16 +9,17 @@ #include <linux/clk-provider.h> #include <linux/clk.h> #include <linux/clkdev.h> +#include <linux/clk/tegra.h> #include <linux/debugfs.h> #include <linux/delay.h> #include <linux/io.h> +#include <linux/module.h> #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/sort.h> #include <linux/string.h>

-#include <soc/tegra/emc.h> #include <soc/tegra/fuse.h> #include <soc/tegra/mc.h>

@@ -562,8 +563,8 @@ static struct emc_timing *tegra_emc_find_timing(struct tegra_emc *emc, return timing; }

-int tegra_emc_prepare_timing_change(struct tegra_emc *emc, - unsigned long rate) +static int tegra_emc_prepare_timing_change(struct tegra_emc *emc, + unsigned long rate) { struct emc_timing *timing = tegra_emc_find_timing(emc, rate); struct emc_timing *last = &emc->last_timing; @@ -790,8 +791,8 @@ int tegra_emc_prepare_timing_change(struct tegra_emc *emc, return 0; }

-void tegra_emc_complete_timing_change(struct tegra_emc *emc, - unsigned long rate) +static void tegra_emc_complete_timing_change(struct tegra_emc *emc, + unsigned long rate) { struct emc_timing *timing = tegra_emc_find_timing(emc, rate); struct emc_timing *last = &emc->last_timing; @@ -987,6 +988,7 @@ static const struct of_device_id tegra_emc_of_match[] = { { .compatible = "nvidia,tegra132-emc" }, {} }; +MODULE_DEVICE_TABLE(of, tegra_emc_of_match);

static struct device_node * tegra_emc_find_node_by_ram_code(struct device_node *node, u32 ram_code) @@ -1226,9 +1228,19 @@ static int tegra_emc_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, emc);

+ tegra124_clk_set_emc_callbacks(tegra_emc_prepare_timing_change, + tegra_emc_complete_timing_change); + if (IS_ENABLED(CONFIG_DEBUG_FS)) emc_debugfs_init(&pdev->dev, emc);

+ /* + * Don't allow the kernel module to be unloaded. Unloading adds some + * extra complexity which doesn't really worth the effort in a case of + * this driver. + */ + try_module_get(THIS_MODULE); + return 0; };

@@ -1240,9 +1252,8 @@ static struct platform_driver tegra_emc_driver = { .suppress_bind_attrs = true, }, }; +module_platform_driver(tegra_emc_driver);

-static int tegra_emc_init(void) -{ - return platform_driver_register(&tegra_emc_driver); -} -subsys_initcall(tegra_emc_init); +MODULE_AUTHOR("Mikko Perttunen mperttunen@nvidia.com"); +MODULE_DESCRIPTION("NVIDIA Tegra124 EMC driver"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/clk/tegra.h b/include/linux/clk/tegra.h index 3f01d43f0598..eb016fc9cc0b 100644 --- a/include/linux/clk/tegra.h +++ b/include/linux/clk/tegra.h @@ -136,6 +136,7 @@ extern void tegra210_clk_emc_dll_update_setting(u32 emc_dll_src_value); extern void tegra210_clk_emc_update_setting(u32 emc_src_value);

struct clk; +struct tegra_emc;

typedef long (tegra20_clk_emc_round_cb)(unsigned long rate, unsigned long min_rate, @@ -146,6 +147,13 @@ void tegra20_clk_set_emc_round_callback(tegra20_clk_emc_round_cb *round_cb, void *cb_arg); int tegra20_clk_prepare_emc_mc_same_freq(struct clk *emc_clk, bool same);

+typedef int (tegra124_emc_prepare_timing_change_cb)(struct tegra_emc *emc, + unsigned long rate); +typedef void (tegra124_emc_complete_timing_change_cb)(struct tegra_emc *emc, + unsigned long rate); +void tegra124_clk_set_emc_callbacks(tegra124_emc_prepare_timing_change_cb *prep_cb, + tegra124_emc_complete_timing_change_cb *complete_cb); + struct tegra210_clk_emc_config { unsigned long rate; bool same_freq; diff --git a/include/soc/tegra/emc.h b/include/soc/tegra/emc.h deleted file mode 100644 index 05199a97ccf4..000000000000 --- a/include/soc/tegra/emc.h +++ /dev/null @@ -1,16 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Copyright (c) 2014 NVIDIA Corporation. All rights reserved. - */ - -#ifndef __SOC_TEGRA_EMC_H__ -#define __SOC_TEGRA_EMC_H__ - -struct tegra_emc; - -int tegra_emc_prepare_timing_change(struct tegra_emc *emc, - unsigned long rate); -void tegra_emc_complete_timing_change(struct tegra_emc *emc, - unsigned long rate); - -#endif /* __SOC_TEGRA_EMC_H__ */