From 6d5b988e7dc56bb97c39bdcbc006fadcd6ca371b Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Tue, 5 Nov 2013 17:33:17 -0700 Subject: [PATCH] clk: tegra: implement a reset driver The Tegra CAR module implements both a clock and reset controller. So far, the driver exposes the clock feature via the common clock API and the reset feature using a custom API. This patch adds an implementation of the common reset framework API (include/linux/reset*.h). The legacy reset implementation will be removed once all drivers have been converted. Signed-off-by: Stephen Warren Reviewed-by: Thierry Reding Acked-By: Peter De Schrijver --- drivers/clk/tegra/clk-tegra114.c | 3 +- drivers/clk/tegra/clk-tegra124.c | 2 +- drivers/clk/tegra/clk-tegra20.c | 3 +- drivers/clk/tegra/clk-tegra30.c | 3 +- drivers/clk/tegra/clk.c | 50 +++++++++++++++++++++++++++++++- drivers/clk/tegra/clk.h | 2 +- 6 files changed, 57 insertions(+), 6 deletions(-) diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c index 29b912582e3d..90d9d25f2228 100644 --- a/drivers/clk/tegra/clk-tegra114.c +++ b/drivers/clk/tegra/clk-tegra114.c @@ -1460,7 +1460,8 @@ static void __init tegra114_clock_init(struct device_node *np) return; } - clks = tegra_clk_init(TEGRA114_CLK_CLK_MAX, TEGRA114_CLK_PERIPH_BANKS); + clks = tegra_clk_init(clk_base, TEGRA114_CLK_CLK_MAX, + TEGRA114_CLK_PERIPH_BANKS); if (!clks) return; diff --git a/drivers/clk/tegra/clk-tegra124.c b/drivers/clk/tegra/clk-tegra124.c index 0ef4485e9b0a..aff86b5bc745 100644 --- a/drivers/clk/tegra/clk-tegra124.c +++ b/drivers/clk/tegra/clk-tegra124.c @@ -1398,7 +1398,7 @@ static void __init tegra124_clock_init(struct device_node *np) return; } - clks = tegra_clk_init(TEGRA124_CLK_CLK_MAX, 6); + clks = tegra_clk_init(clk_base, TEGRA124_CLK_CLK_MAX, 6); if (!clks) return; diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c index b3b7204acfe7..5a6a60d9443a 100644 --- a/drivers/clk/tegra/clk-tegra20.c +++ b/drivers/clk/tegra/clk-tegra20.c @@ -1109,7 +1109,8 @@ static void __init tegra20_clock_init(struct device_node *np) BUG(); } - clks = tegra_clk_init(TEGRA20_CLK_CLK_MAX, TEGRA20_CLK_PERIPH_BANKS); + clks = tegra_clk_init(clk_base, TEGRA20_CLK_CLK_MAX, + TEGRA20_CLK_PERIPH_BANKS); if (!clks) return; diff --git a/drivers/clk/tegra/clk-tegra30.c b/drivers/clk/tegra/clk-tegra30.c index dcb6843b3a89..2e47383418c8 100644 --- a/drivers/clk/tegra/clk-tegra30.c +++ b/drivers/clk/tegra/clk-tegra30.c @@ -1427,7 +1427,8 @@ static void __init tegra30_clock_init(struct device_node *np) BUG(); } - clks = tegra_clk_init(TEGRA30_CLK_CLK_MAX, TEGRA30_CLK_PERIPH_BANKS); + clks = tegra_clk_init(clk_base, TEGRA30_CLK_CLK_MAX, + TEGRA30_CLK_PERIPH_BANKS); if (!clks) return; diff --git a/drivers/clk/tegra/clk.c b/drivers/clk/tegra/clk.c index a12a5f5107ec..c0a7d7723510 100644 --- a/drivers/clk/tegra/clk.c +++ b/drivers/clk/tegra/clk.c @@ -18,6 +18,8 @@ #include #include #include +#include +#include #include "clk.h" @@ -121,6 +123,35 @@ static struct tegra_clk_periph_regs periph_regs[] = { }, }; +static void __iomem *clk_base; + +static int tegra_clk_rst_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + /* + * If peripheral is on the APB bus then we must read the APB bus to + * flush the write operation in apb bus. This will avoid peripheral + * access after disabling clock. Since the reset driver has no + * knowledge of which reset IDs represent which devices, simply do + * this all the time. + */ + tegra_read_chipid(); + + writel_relaxed(BIT(id % 32), + clk_base + periph_regs[id / 32].rst_set_reg); + + return 0; +} + +static int tegra_clk_rst_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + writel_relaxed(BIT(id % 32), + clk_base + periph_regs[id / 32].rst_clr_reg); + + return 0; +} + struct tegra_clk_periph_regs *get_reg_bank(int clkid) { int reg_bank = clkid / 32; @@ -133,8 +164,10 @@ struct tegra_clk_periph_regs *get_reg_bank(int clkid) } } -struct clk ** __init tegra_clk_init(int num, int banks) +struct clk ** __init tegra_clk_init(void __iomem *regs, int num, int banks) { + clk_base = regs; + if (WARN_ON(banks > ARRAY_SIZE(periph_regs))) return NULL; @@ -203,6 +236,17 @@ void __init tegra_init_from_table(struct tegra_clk_init_table *tbl, } } +static struct reset_control_ops rst_ops = { + .assert = tegra_clk_rst_assert, + .deassert = tegra_clk_rst_deassert, +}; + +static struct reset_controller_dev rst_ctlr = { + .ops = &rst_ops, + .owner = THIS_MODULE, + .of_reset_n_cells = 1, +}; + void __init tegra_add_of_provider(struct device_node *np) { int i; @@ -220,6 +264,10 @@ void __init tegra_add_of_provider(struct device_node *np) clk_data.clks = clks; clk_data.clk_num = clk_num; of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data); + + rst_ctlr.of_node = np; + rst_ctlr.nr_resets = clk_num * 32; + reset_controller_register(&rst_ctlr); } void __init tegra_register_devclks(struct tegra_devclk *dev_clks, int num) diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h index 40fb011233c0..07c62f997371 100644 --- a/drivers/clk/tegra/clk.h +++ b/drivers/clk/tegra/clk.h @@ -597,7 +597,7 @@ void tegra_init_dup_clks(struct tegra_clk_duplicate *dup_list, struct clk *clks[], int clk_max); struct tegra_clk_periph_regs *get_reg_bank(int clkid); -struct clk **tegra_clk_init(int num, int periph_banks); +struct clk **tegra_clk_init(void __iomem *clk_base, int num, int periph_banks); struct clk **tegra_lookup_dt_id(int clk_id, struct tegra_clk *tegra_clk); -- 2.20.1