clk: iproc: add initial common clock support

This adds basic and generic support for various iProc PLLs and clocks
including the ARMPLL, GENPLL, LCPLL, MIPIPLL, and ASIU clocks.

SoCs under the iProc architecture can define their specific register
offsets and clock parameters for their PLL and clock controllers. These
parameters can be passed as arugments into the generic iProc PLL and
clock setup functions

Derived from code originally provided by Jonathan Richardson
<jonathar@broadcom.com>

Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>

1 files changed, 178 insertions, 0 deletions

diff --git a/drivers/clk/bcm/clk-iproc.h b/drivers/clk/bcm/clk-iproc.h
new file mode 100644
index 000000000000..d834b7abd5c6
--- /dev/null
+++ b/drivers/clk/bcm/clk-iproc.h
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _CLK_IPROC_H
+#define _CLK_IPROC_H
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/clk-provider.h>
+
+#define IPROC_CLK_NAME_LEN 25
+#define IPROC_CLK_INVALID_OFFSET 0xffffffff
+#define bit_mask(width) ((1 << (width)) - 1)
+
+/* clocks that should not be disabled at runtime */
+#define IPROC_CLK_AON BIT(0)
+
+/* PLL that requires gating through ASIU */
+#define IPROC_CLK_PLL_ASIU BIT(1)
+
+/* PLL that has fractional part of the NDIV */
+#define IPROC_CLK_PLL_HAS_NDIV_FRAC BIT(2)
+
+/*
+ * Some of the iProc PLL/clocks may have an ASIC bug that requires read back
+ * of the same register following the write to flush the write transaction into
+ * the intended register
+ */
+#define IPROC_CLK_NEEDS_READ_BACK BIT(3)
+
+/*
+ * Some PLLs require the PLL SW override bit to be set before changes can be
+ * applied to the PLL
+ */
+#define IPROC_CLK_PLL_NEEDS_SW_CFG BIT(4)
+
+/*
+ * Parameters for VCO frequency configuration
+ *
+ * VCO frequency =
+ * ((ndiv_int + ndiv_frac / 2^20) * (ref freqeuncy  / pdiv)
+ */
+struct iproc_pll_vco_param {
+	unsigned long rate;
+	unsigned int ndiv_int;
+	unsigned int ndiv_frac;
+	unsigned int pdiv;
+};
+
+struct iproc_clk_reg_op {
+	unsigned int offset;
+	unsigned int shift;
+	unsigned int width;
+};
+
+/*
+ * Clock gating control at the top ASIU level
+ */
+struct iproc_asiu_gate {
+	unsigned int offset;
+	unsigned int en_shift;
+};
+
+/*
+ * Control of powering on/off of a PLL
+ *
+ * Before powering off a PLL, input isolation (ISO) needs to be enabled
+ */
+struct iproc_pll_aon_pwr_ctrl {
+	unsigned int offset;
+	unsigned int pwr_width;
+	unsigned int pwr_shift;
+	unsigned int iso_shift;
+};
+
+/*
+ * Control of the PLL reset, with Ki, Kp, and Ka parameters
+ */
+struct iproc_pll_reset_ctrl {
+	unsigned int offset;
+	unsigned int reset_shift;
+	unsigned int p_reset_shift;
+	unsigned int ki_shift;
+	unsigned int ki_width;
+	unsigned int kp_shift;
+	unsigned int kp_width;
+	unsigned int ka_shift;
+	unsigned int ka_width;
+};
+
+/*
+ * To enable SW control of the PLL
+ */
+struct iproc_pll_sw_ctrl {
+	unsigned int offset;
+	unsigned int shift;
+};
+
+struct iproc_pll_vco_ctrl {
+	unsigned int u_offset;
+	unsigned int l_offset;
+};
+
+/*
+ * Main PLL control parameters
+ */
+struct iproc_pll_ctrl {
+	unsigned long flags;
+	struct iproc_pll_aon_pwr_ctrl aon;
+	struct iproc_asiu_gate asiu;
+	struct iproc_pll_reset_ctrl reset;
+	struct iproc_pll_sw_ctrl sw_ctrl;
+	struct iproc_clk_reg_op ndiv_int;
+	struct iproc_clk_reg_op ndiv_frac;
+	struct iproc_clk_reg_op pdiv;
+	struct iproc_pll_vco_ctrl vco_ctrl;
+	struct iproc_clk_reg_op status;
+};
+
+/*
+ * Controls enabling/disabling a PLL derived clock
+ */
+struct iproc_clk_enable_ctrl {
+	unsigned int offset;
+	unsigned int enable_shift;
+	unsigned int hold_shift;
+	unsigned int bypass_shift;
+};
+
+/*
+ * Main clock control parameters for clocks derived from the PLLs
+ */
+struct iproc_clk_ctrl {
+	unsigned int channel;
+	unsigned long flags;
+	struct iproc_clk_enable_ctrl enable;
+	struct iproc_clk_reg_op mdiv;
+};
+
+/*
+ * Divisor of the ASIU clocks
+ */
+struct iproc_asiu_div {
+	unsigned int offset;
+	unsigned int en_shift;
+	unsigned int high_shift;
+	unsigned int high_width;
+	unsigned int low_shift;
+	unsigned int low_width;
+};
+
+void __init iproc_armpll_setup(struct device_node *node);
+void __init iproc_pll_clk_setup(struct device_node *node,
+				const struct iproc_pll_ctrl *pll_ctrl,
+				const struct iproc_pll_vco_param *vco,
+				unsigned int num_vco_entries,
+				const struct iproc_clk_ctrl *clk_ctrl,
+				unsigned int num_clks);
+void __init iproc_asiu_setup(struct device_node *node,
+			     const struct iproc_asiu_div *div,
+			     const struct iproc_asiu_gate *gate,
+			     unsigned int num_clks);
+
+#endif /* _CLK_IPROC_H */