From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 drivers/cpufreq/cris-artpec3-cpufreq.c | 92 ++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 drivers/cpufreq/cris-artpec3-cpufreq.c

(limited to 'drivers/cpufreq/cris-artpec3-cpufreq.c')

diff --git a/drivers/cpufreq/cris-artpec3-cpufreq.c b/drivers/cpufreq/cris-artpec3-cpufreq.c
new file mode 100644
index 000000000..601b88c49
--- /dev/null
+++ b/drivers/cpufreq/cris-artpec3-cpufreq.c
@@ -0,0 +1,92 @@
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/cpufreq.h>
+#include <hwregs/reg_map.h>
+#include <hwregs/reg_rdwr.h>
+#include <hwregs/clkgen_defs.h>
+#include <hwregs/ddr2_defs.h>
+
+static int
+cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val,
+	void *data);
+
+static struct notifier_block cris_sdram_freq_notifier_block = {
+	.notifier_call = cris_sdram_freq_notifier
+};
+
+static struct cpufreq_frequency_table cris_freq_table[] = {
+	{0, 0x01, 6000},
+	{0, 0x02, 200000},
+	{0, 0, CPUFREQ_TABLE_END},
+};
+
+static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
+{
+	reg_clkgen_rw_clk_ctrl clk_ctrl;
+	clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
+	return clk_ctrl.pll ? 200000 : 6000;
+}
+
+static int cris_freq_target(struct cpufreq_policy *policy, unsigned int state)
+{
+	reg_clkgen_rw_clk_ctrl clk_ctrl;
+	clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
+
+	local_irq_disable();
+
+	/* Even though we may be SMP they will share the same clock
+	 * so all settings are made on CPU0. */
+	if (cris_freq_table[state].frequency == 200000)
+		clk_ctrl.pll = 1;
+	else
+		clk_ctrl.pll = 0;
+	REG_WR(clkgen, regi_clkgen, rw_clk_ctrl, clk_ctrl);
+
+	local_irq_enable();
+
+	return 0;
+}
+
+static int cris_freq_cpu_init(struct cpufreq_policy *policy)
+{
+	return cpufreq_generic_init(policy, cris_freq_table, 1000000);
+}
+
+static struct cpufreq_driver cris_freq_driver = {
+	.get	= cris_freq_get_cpu_frequency,
+	.verify	= cpufreq_generic_frequency_table_verify,
+	.target_index = cris_freq_target,
+	.init	= cris_freq_cpu_init,
+	.name	= "cris_freq",
+	.attr	= cpufreq_generic_attr,
+};
+
+static int __init cris_freq_init(void)
+{
+	int ret;
+	ret = cpufreq_register_driver(&cris_freq_driver);
+	cpufreq_register_notifier(&cris_sdram_freq_notifier_block,
+		CPUFREQ_TRANSITION_NOTIFIER);
+	return ret;
+}
+
+static int
+cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val,
+	void *data)
+{
+	int i;
+	struct cpufreq_freqs *freqs = data;
+	if (val == CPUFREQ_PRECHANGE) {
+		reg_ddr2_rw_cfg cfg =
+		  REG_RD(ddr2, regi_ddr2_ctrl, rw_cfg);
+		cfg.ref_interval = (freqs->new == 200000 ? 1560 : 46);
+
+		if (freqs->new == 200000)
+			for (i = 0; i < 50000; i++);
+		REG_WR(bif_core, regi_bif_core, rw_sdram_timing, timing);
+	}
+	return 0;
+}
+
+
+module_init(cris_freq_init);
-- 
cgit v1.2.3-54-g00ecf