1 files changed, 255 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c b/arch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c
new file mode 100644
index 000000000..edf046b47
--- /dev/null
+++ b/arch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * OMAP2xxx DVFS virtual clock functions
+ *
+ * Copyright (C) 2005-2008, 2012 Texas Instruments, Inc.
+ * Copyright (C) 2004-2010 Nokia Corporation
+ *
+ * Contacts:
+ * Richard Woodruff <r-woodruff2@ti.com>
+ * Paul Walmsley
+ *
+ * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
+ * Gordon McNutt and RidgeRun, Inc.
+ *
+ * XXX Some of this code should be replaceable by the upcoming OPP layer
+ * code.  However, some notion of "rate set" is probably still necessary
+ * for OMAP2xxx at least.  Rate sets should be generalized so they can be
+ * used for any OMAP chip, not just OMAP2xxx.  In particular, Richard Woodruff
+ * has in the past expressed a preference to use rate sets for OPP changes,
+ * rather than dynamically recalculating the clock tree, so if someone wants
+ * this badly enough to write the code to handle it, we should support it
+ * as an option.
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/cpufreq.h>
+#include <linux/slab.h>
+
+#include "soc.h"
+#include "clock.h"
+#include "clock2xxx.h"
+#include "opp2xxx.h"
+#include "cm2xxx.h"
+#include "cm-regbits-24xx.h"
+#include "sdrc.h"
+#include "sram.h"
+
+const struct prcm_config *curr_prcm_set;
+const struct prcm_config *rate_table;
+
+/*
+ * sys_ck_rate: the rate of the external high-frequency clock
+ * oscillator on the board.  Set by the SoC-specific clock init code.
+ * Once set during a boot, will not change.
+ */
+static unsigned long sys_ck_rate;
+
+/**
+ * omap2_table_mpu_recalc - just return the MPU speed
+ * @clk: virt_prcm_set struct clk
+ *
+ * Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
+ */
+unsigned long omap2_table_mpu_recalc(struct clk_hw *clk,
+				     unsigned long parent_rate)
+{
+	return curr_prcm_set->mpu_speed;
+}
+
+/*
+ * Look for a rate equal or less than the target rate given a configuration set.
+ *
+ * What's not entirely clear is "which" field represents the key field.
+ * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
+ * just uses the ARM rates.
+ */
+long omap2_round_to_table_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long *parent_rate)
+{
+	const struct prcm_config *ptr;
+	long highest_rate;
+
+	highest_rate = -EINVAL;
+
+	for (ptr = rate_table; ptr->mpu_speed; ptr++) {
+		if (!(ptr->flags & cpu_mask))
+			continue;
+		if (ptr->xtal_speed != sys_ck_rate)
+			continue;
+
+		highest_rate = ptr->mpu_speed;
+
+		/* Can check only after xtal frequency check */
+		if (ptr->mpu_speed <= rate)
+			break;
+	}
+	return highest_rate;
+}
+
+/* Sets basic clocks based on the specified rate */
+int omap2_select_table_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	u32 cur_rate, done_rate, bypass = 0;
+	const struct prcm_config *prcm;
+	unsigned long found_speed = 0;
+	unsigned long flags;
+
+	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
+		if (!(prcm->flags & cpu_mask))
+			continue;
+
+		if (prcm->xtal_speed != sys_ck_rate)
+			continue;
+
+		if (prcm->mpu_speed <= rate) {
+			found_speed = prcm->mpu_speed;
+			break;
+		}
+	}
+
+	if (!found_speed) {
+		printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
+		       rate / 1000000);
+		return -EINVAL;
+	}
+
+	curr_prcm_set = prcm;
+	cur_rate = omap2xxx_clk_get_core_rate();
+
+	if (prcm->dpll_speed == cur_rate / 2) {
+		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
+	} else if (prcm->dpll_speed == cur_rate * 2) {
+		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
+	} else if (prcm->dpll_speed != cur_rate) {
+		local_irq_save(flags);
+
+		if (prcm->dpll_speed == prcm->xtal_speed)
+			bypass = 1;
+
+		if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
+		    CORE_CLK_SRC_DPLL_X2)
+			done_rate = CORE_CLK_SRC_DPLL_X2;
+		else
+			done_rate = CORE_CLK_SRC_DPLL;
+
+		omap2xxx_cm_set_mod_dividers(prcm->cm_clksel_mpu,
+					     prcm->cm_clksel_dsp,
+					     prcm->cm_clksel_gfx,
+					     prcm->cm_clksel1_core,
+					     prcm->cm_clksel_mdm);
+
+		/* x2 to enter omap2xxx_sdrc_init_params() */
+		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
+
+		omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
+			       bypass);
+
+		omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
+		omap2xxx_sdrc_reprogram(done_rate, 0);
+
+		local_irq_restore(flags);
+	}
+
+	return 0;
+}
+
+/**
+ * omap2xxx_clkt_vps_check_bootloader_rate - determine which of the rate
+ * table sets matches the current CORE DPLL hardware rate
+ *
+ * Check the MPU rate set by bootloader.  Sets the 'curr_prcm_set'
+ * global to point to the active rate set when found; otherwise, sets
+ * it to NULL.  No return value;
+ */
+void omap2xxx_clkt_vps_check_bootloader_rates(void)
+{
+	const struct prcm_config *prcm = NULL;
+	unsigned long rate;
+
+	rate = omap2xxx_clk_get_core_rate();
+	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
+		if (!(prcm->flags & cpu_mask))
+			continue;
+		if (prcm->xtal_speed != sys_ck_rate)
+			continue;
+		if (prcm->dpll_speed <= rate)
+			break;
+	}
+	curr_prcm_set = prcm;
+}
+
+/**
+ * omap2xxx_clkt_vps_late_init - store a copy of the sys_ck rate
+ *
+ * Store a copy of the sys_ck rate for later use by the OMAP2xxx DVFS
+ * code.  (The sys_ck rate does not -- or rather, must not -- change
+ * during kernel runtime.)  Must be called after we have a valid
+ * sys_ck rate, but before the virt_prcm_set clock rate is
+ * recalculated.  No return value.
+ */
+void omap2xxx_clkt_vps_late_init(void)
+{
+	struct clk *c;
+
+	c = clk_get(NULL, "sys_ck");
+	if (IS_ERR(c)) {
+		WARN(1, "could not locate sys_ck\n");
+	} else {
+		sys_ck_rate = clk_get_rate(c);
+		clk_put(c);
+	}
+}
+
+#ifdef CONFIG_OF
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+
+static const struct clk_ops virt_prcm_set_ops = {
+	.recalc_rate	= &omap2_table_mpu_recalc,
+	.set_rate	= &omap2_select_table_rate,
+	.round_rate	= &omap2_round_to_table_rate,
+};
+
+/**
+ * omap2xxx_clkt_vps_init - initialize virt_prcm_set clock
+ *
+ * Does a manual init for the virtual prcm DVFS clock for OMAP2. This
+ * function is called only from omap2 DT clock init, as the virtual
+ * node is not modelled in the DT clock data.
+ */
+void omap2xxx_clkt_vps_init(void)
+{
+	struct clk_init_data init = { NULL };
+	struct clk_hw_omap *hw = NULL;
+	struct clk *clk;
+	const char *parent_name = "mpu_ck";
+
+	omap2xxx_clkt_vps_late_init();
+	omap2xxx_clkt_vps_check_bootloader_rates();
+
+	hw = kzalloc(sizeof(*hw), GFP_KERNEL);
+	if (!hw)
+		return;
+	init.name = "virt_prcm_set";
+	init.ops = &virt_prcm_set_ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	hw->hw.init = &init;
+
+	clk = clk_register(NULL, &hw->hw);
+	if (IS_ERR(clk)) {
+		printk(KERN_ERR "Failed to register clock\n");
+		kfree(hw);
+		return;
+	}
+
+	clkdev_create(clk, "cpufreq_ck", NULL);
+}
+#endif