[PATCH V2] clk: tegra: implement a reset driver
Stephen Warren
swarren at wwwdotorg.org
Tue Dec 3 15:28:49 EST 2013
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>
---
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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