[PATCH V2] clk: tegra: implement a reset driver
Peter De Schrijver
pdeschrijver at nvidia.com
Wed Dec 4 04:31:26 EST 2013
On Tue, Dec 03, 2013 at 09:28:49PM +0100, Stephen Warren wrote:
> From: Stephen Warren <swarren at nvidia.com>
>
> 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.
>
> Cc: pdeschrijver at nvidia.com
> Cc: linux-tegra at vger.kernel.org
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: Mike Turquette <mturquette at linaro.org>
> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> Reviewed-by: Thierry Reding <treding at nvidia.com>
Acked-By: Peter De Schrijver <pdeschrijver at nvidia.com>
> ---
> v2: Move the added lines in the file, to avoid the need for function
> prototypes.
>
> Peter, Mike,
>
> This patch is part of a series with strong internal depdendencies. I'm
> looking for an ack so that I can take the entire series through the Tegra
> and arm-soc trees. The series will be part of a stable branch that can be
> merged into other subsystems if needed to avoid/resolve dependencies.
> ---
> 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 70bfefebcca5..84d9003ae816 100644
> --- a/drivers/clk/tegra/clk-tegra114.c
> +++ b/drivers/clk/tegra/clk-tegra114.c
> @@ -1457,7 +1457,8 @@ 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 623fbf35ee08..6f8b1d99e5b9 100644
> --- a/drivers/clk/tegra/clk-tegra124.c
> +++ b/drivers/clk/tegra/clk-tegra124.c
> @@ -1402,7 +1402,7 @@ 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 be5bdbab78a6..d438a089354c 100644
> --- a/drivers/clk/tegra/clk-tegra20.c
> +++ b/drivers/clk/tegra/clk-tegra20.c
> @@ -1108,7 +1108,8 @@ 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 92c46f1fb5d1..49465529bb09 100644
> --- a/drivers/clk/tegra/clk-tegra30.c
> +++ b/drivers/clk/tegra/clk-tegra30.c
> @@ -1429,7 +1429,8 @@ 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 <linux/clk-provider.h>
> #include <linux/of.h>
> #include <linux/clk/tegra.h>
> +#include <linux/reset-controller.h>
> +#include <linux/tegra-soc.h>
>
> #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 7f110acfe2a1..39f24959daf7 100644
> --- a/drivers/clk/tegra/clk.h
> +++ b/drivers/clk/tegra/clk.h
> @@ -594,7 +594,7 @@ 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);
>
> --
> 1.8.1.5
>
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