clk: tegra: add Tegra specific clocks

Add Tegra specific clocks, pll, pll_out, peripheral, frac_divider, super.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
[swarren: alloc sizeof(*foo) not sizeof(struct foo), add comments re:
storing pointers to stack variables, make a timeout loop more idiomatic,
use _clk_pll_disable() not clk_disable_pll() from _program_pll() to
avoid redundant lock operations, unified tegra_clk_periph() and
tegra_clk_periph_nodiv(), unified tegra_clk_pll{,e}, rename all clock
registration functions so they don't have the same name as the clock
structs, return -EINVAL from clk_plle_enable when matching table rate
not found, pass ops to _tegra_clk_register_pll rather than a bool.]
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

1 files changed, 179 insertions, 0 deletions

diff --git a/drivers/clk/tegra/clk-periph-gate.c b/drivers/clk/tegra/clk-periph-gate.c
new file mode 100644
index 00000000000..6dd533251e7
--- /dev/null
+++ b/drivers/clk/tegra/clk-periph-gate.c
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/tegra-soc.h>
+
+#include "clk.h"
+
+static DEFINE_SPINLOCK(periph_ref_lock);
+
+/* Macros to assist peripheral gate clock */
+#define read_enb(gate) \
+	readl_relaxed(gate->clk_base + (gate->regs->enb_reg))
+#define write_enb_set(val, gate) \
+	writel_relaxed(val, gate->clk_base + (gate->regs->enb_set_reg))
+#define write_enb_clr(val, gate) \
+	writel_relaxed(val, gate->clk_base + (gate->regs->enb_clr_reg))
+
+#define read_rst(gate) \
+	readl_relaxed(gate->clk_base + (gate->regs->rst_reg))
+#define write_rst_set(val, gate) \
+	writel_relaxed(val, gate->clk_base + (gate->regs->rst_set_reg))
+#define write_rst_clr(val, gate) \
+	writel_relaxed(val, gate->clk_base + (gate->regs->rst_clr_reg))
+
+#define periph_clk_to_bit(periph) (1 << (gate->clk_num % 32))
+
+/* Peripheral gate clock ops */
+static int clk_periph_is_enabled(struct clk_hw *hw)
+{
+	struct tegra_clk_periph_gate *gate = to_clk_periph_gate(hw);
+	int state = 1;
+
+	if (!(read_enb(gate) & periph_clk_to_bit(gate)))
+		state = 0;
+
+	if (!(gate->flags & TEGRA_PERIPH_NO_RESET))
+		if (read_rst(gate) & periph_clk_to_bit(gate))
+			state = 0;
+
+	return state;
+}
+
+static int clk_periph_enable(struct clk_hw *hw)
+{
+	struct tegra_clk_periph_gate *gate = to_clk_periph_gate(hw);
+	unsigned long flags = 0;
+
+	spin_lock_irqsave(&periph_ref_lock, flags);
+
+	gate->enable_refcnt[gate->clk_num]++;
+	if (gate->enable_refcnt[gate->clk_num] > 1) {
+		spin_unlock_irqrestore(&periph_ref_lock, flags);
+		return 0;
+	}
+
+	write_enb_set(periph_clk_to_bit(gate), gate);
+	udelay(2);
+
+	if (!(gate->flags & TEGRA_PERIPH_NO_RESET) &&
+	    !(gate->flags & TEGRA_PERIPH_MANUAL_RESET)) {
+		if (read_rst(gate) & periph_clk_to_bit(gate)) {
+			udelay(5); /* reset propogation delay */
+			write_rst_clr(periph_clk_to_bit(gate), gate);
+		}
+	}
+
+	spin_unlock_irqrestore(&periph_ref_lock, flags);
+
+	return 0;
+}
+
+static void clk_periph_disable(struct clk_hw *hw)
+{
+	struct tegra_clk_periph_gate *gate = to_clk_periph_gate(hw);
+	unsigned long flags = 0;
+
+	spin_lock_irqsave(&periph_ref_lock, flags);
+
+	gate->enable_refcnt[gate->clk_num]--;
+	if (gate->enable_refcnt[gate->clk_num] > 0) {
+		spin_unlock_irqrestore(&periph_ref_lock, flags);
+		return;
+	}
+
+	/*
+	 * If peripheral is in the APB bus then read the APB bus to
+	 * flush the write operation in apb bus. This will avoid the
+	 * peripheral access after disabling clock
+	 */
+	if (gate->flags & TEGRA_PERIPH_ON_APB)
+		tegra_read_chipid();
+
+	write_enb_clr(periph_clk_to_bit(gate), gate);
+
+	spin_unlock_irqrestore(&periph_ref_lock, flags);
+}
+
+void tegra_periph_reset(struct tegra_clk_periph_gate *gate, bool assert)
+{
+	if (gate->flags & TEGRA_PERIPH_NO_RESET)
+		return;
+
+	if (assert) {
+		/*
+		 * If peripheral is in the APB bus then read the APB bus to
+		 * flush the write operation in apb bus. This will avoid the
+		 * peripheral access after disabling clock
+		 */
+		if (gate->flags & TEGRA_PERIPH_ON_APB)
+			tegra_read_chipid();
+
+		write_rst_set(periph_clk_to_bit(gate), gate);
+	} else {
+		write_rst_clr(periph_clk_to_bit(gate), gate);
+	}
+}
+
+const struct clk_ops tegra_clk_periph_gate_ops = {
+	.is_enabled = clk_periph_is_enabled,
+	.enable = clk_periph_enable,
+	.disable = clk_periph_disable,
+};
+
+struct clk *tegra_clk_register_periph_gate(const char *name,
+		const char *parent_name, u8 gate_flags, void __iomem *clk_base,
+		unsigned long flags, int clk_num,
+		struct tegra_clk_periph_regs *pregs, int *enable_refcnt)
+{
+	struct tegra_clk_periph_gate *gate;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+	if (!gate) {
+		pr_err("%s: could not allocate periph gate clk\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	init.name = name;
+	init.flags = flags;
+	init.parent_names = parent_name ? &parent_name : NULL;
+	init.num_parents = parent_name ? 1 : 0;
+	init.ops = &tegra_clk_periph_gate_ops;
+
+	gate->magic = TEGRA_CLK_PERIPH_GATE_MAGIC;
+	gate->clk_base = clk_base;
+	gate->clk_num = clk_num;
+	gate->flags = gate_flags;
+	gate->enable_refcnt = enable_refcnt;
+	gate->regs = pregs;
+
+	/* Data in .init is copied by clk_register(), so stack variable OK */
+	gate->hw.init = &init;
+
+	clk = clk_register(NULL, &gate->hw);
+	if (IS_ERR(clk))
+		kfree(gate);
+
+	return clk;
+}