summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/s3c2412-cpufreq.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /drivers/cpufreq/s3c2412-cpufreq.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/cpufreq/s3c2412-cpufreq.c')
-rw-r--r--drivers/cpufreq/s3c2412-cpufreq.c240
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/cpufreq/s3c2412-cpufreq.c b/drivers/cpufreq/s3c2412-cpufreq.c
new file mode 100644
index 000000000..5945945ea
--- /dev/null
+++ b/drivers/cpufreq/s3c2412-cpufreq.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2008 Simtec Electronics
+ * http://armlinux.simtec.co.uk/
+ * Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C2412 CPU Frequency scalling
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/cpufreq.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/soc/samsung/s3c-cpufreq-core.h>
+#include <linux/soc/samsung/s3c-pm.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/map.h>
+
+#define S3C2412_CLKDIVN_PDIVN (1<<2)
+#define S3C2412_CLKDIVN_HDIVN_MASK (3<<0)
+#define S3C2412_CLKDIVN_ARMDIVN (1<<3)
+#define S3C2412_CLKDIVN_DVSEN (1<<4)
+#define S3C2412_CLKDIVN_HALFHCLK (1<<5)
+#define S3C2412_CLKDIVN_USB48DIV (1<<6)
+#define S3C2412_CLKDIVN_UARTDIV_MASK (15<<8)
+#define S3C2412_CLKDIVN_UARTDIV_SHIFT (8)
+#define S3C2412_CLKDIVN_I2SDIV_MASK (15<<12)
+#define S3C2412_CLKDIVN_I2SDIV_SHIFT (12)
+#define S3C2412_CLKDIVN_CAMDIV_MASK (15<<16)
+#define S3C2412_CLKDIVN_CAMDIV_SHIFT (16)
+
+/* our clock resources. */
+static struct clk *xtal;
+static struct clk *fclk;
+static struct clk *hclk;
+static struct clk *armclk;
+
+/* HDIV: 1, 2, 3, 4, 6, 8 */
+
+static int s3c2412_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
+{
+ unsigned int hdiv, pdiv, armdiv, dvs;
+ unsigned long hclk, fclk, armclk, armdiv_clk;
+ unsigned long hclk_max;
+
+ fclk = cfg->freq.fclk;
+ armclk = cfg->freq.armclk;
+ hclk_max = cfg->max.hclk;
+
+ /* We can't run hclk above armclk as at the best we have to
+ * have armclk and hclk in dvs mode. */
+
+ if (hclk_max > armclk)
+ hclk_max = armclk;
+
+ s3c_freq_dbg("%s: fclk=%lu, armclk=%lu, hclk_max=%lu\n",
+ __func__, fclk, armclk, hclk_max);
+ s3c_freq_dbg("%s: want f=%lu, arm=%lu, h=%lu, p=%lu\n",
+ __func__, cfg->freq.fclk, cfg->freq.armclk,
+ cfg->freq.hclk, cfg->freq.pclk);
+
+ armdiv = fclk / armclk;
+
+ if (armdiv < 1)
+ armdiv = 1;
+ if (armdiv > 2)
+ armdiv = 2;
+
+ cfg->divs.arm_divisor = armdiv;
+ armdiv_clk = fclk / armdiv;
+
+ hdiv = armdiv_clk / hclk_max;
+ if (hdiv < 1)
+ hdiv = 1;
+
+ cfg->freq.hclk = hclk = armdiv_clk / hdiv;
+
+ /* set dvs depending on whether we reached armclk or not. */
+ cfg->divs.dvs = dvs = armclk < armdiv_clk;
+
+ /* update the actual armclk we achieved. */
+ cfg->freq.armclk = dvs ? hclk : armdiv_clk;
+
+ s3c_freq_dbg("%s: armclk %lu, hclk %lu, armdiv %d, hdiv %d, dvs %d\n",
+ __func__, armclk, hclk, armdiv, hdiv, cfg->divs.dvs);
+
+ if (hdiv > 4)
+ goto invalid;
+
+ pdiv = (hclk > cfg->max.pclk) ? 2 : 1;
+
+ if ((hclk / pdiv) > cfg->max.pclk)
+ pdiv++;
+
+ cfg->freq.pclk = hclk / pdiv;
+
+ s3c_freq_dbg("%s: pdiv %d\n", __func__, pdiv);
+
+ if (pdiv > 2)
+ goto invalid;
+
+ pdiv *= hdiv;
+
+ /* store the result, and then return */
+
+ cfg->divs.h_divisor = hdiv * armdiv;
+ cfg->divs.p_divisor = pdiv * armdiv;
+
+ return 0;
+
+invalid:
+ return -EINVAL;
+}
+
+static void s3c2412_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
+{
+ unsigned long clkdiv;
+ unsigned long olddiv;
+
+ olddiv = clkdiv = s3c24xx_read_clkdivn();
+
+ /* clear off current clock info */
+
+ clkdiv &= ~S3C2412_CLKDIVN_ARMDIVN;
+ clkdiv &= ~S3C2412_CLKDIVN_HDIVN_MASK;
+ clkdiv &= ~S3C2412_CLKDIVN_PDIVN;
+
+ if (cfg->divs.arm_divisor == 2)
+ clkdiv |= S3C2412_CLKDIVN_ARMDIVN;
+
+ clkdiv |= ((cfg->divs.h_divisor / cfg->divs.arm_divisor) - 1);
+
+ if (cfg->divs.p_divisor != cfg->divs.h_divisor)
+ clkdiv |= S3C2412_CLKDIVN_PDIVN;
+
+ s3c_freq_dbg("%s: div %08lx => %08lx\n", __func__, olddiv, clkdiv);
+ s3c24xx_write_clkdivn(clkdiv);
+
+ clk_set_parent(armclk, cfg->divs.dvs ? hclk : fclk);
+}
+
+/* set the default cpu frequency information, based on an 200MHz part
+ * as we have no other way of detecting the speed rating in software.
+ */
+
+static struct s3c_cpufreq_info s3c2412_cpufreq_info = {
+ .max = {
+ .fclk = 200000000,
+ .hclk = 100000000,
+ .pclk = 50000000,
+ },
+
+ .latency = 5000000, /* 5ms */
+
+ .locktime_m = 150,
+ .locktime_u = 150,
+ .locktime_bits = 16,
+
+ .name = "s3c2412",
+ .set_refresh = s3c2412_cpufreq_setrefresh,
+ .set_divs = s3c2412_cpufreq_setdivs,
+ .calc_divs = s3c2412_cpufreq_calcdivs,
+
+ .calc_iotiming = s3c2412_iotiming_calc,
+ .set_iotiming = s3c2412_iotiming_set,
+ .get_iotiming = s3c2412_iotiming_get,
+
+ .debug_io_show = s3c_cpufreq_debugfs_call(s3c2412_iotiming_debugfs),
+};
+
+static int s3c2412_cpufreq_add(struct device *dev,
+ struct subsys_interface *sif)
+{
+ unsigned long fclk_rate;
+
+ hclk = clk_get(NULL, "hclk");
+ if (IS_ERR(hclk)) {
+ pr_err("cannot find hclk clock\n");
+ return -ENOENT;
+ }
+
+ fclk = clk_get(NULL, "fclk");
+ if (IS_ERR(fclk)) {
+ pr_err("cannot find fclk clock\n");
+ goto err_fclk;
+ }
+
+ fclk_rate = clk_get_rate(fclk);
+ if (fclk_rate > 200000000) {
+ pr_info("fclk %ld MHz, assuming 266MHz capable part\n",
+ fclk_rate / 1000000);
+ s3c2412_cpufreq_info.max.fclk = 266000000;
+ s3c2412_cpufreq_info.max.hclk = 133000000;
+ s3c2412_cpufreq_info.max.pclk = 66000000;
+ }
+
+ armclk = clk_get(NULL, "armclk");
+ if (IS_ERR(armclk)) {
+ pr_err("cannot find arm clock\n");
+ goto err_armclk;
+ }
+
+ xtal = clk_get(NULL, "xtal");
+ if (IS_ERR(xtal)) {
+ pr_err("cannot find xtal clock\n");
+ goto err_xtal;
+ }
+
+ return s3c_cpufreq_register(&s3c2412_cpufreq_info);
+
+err_xtal:
+ clk_put(armclk);
+err_armclk:
+ clk_put(fclk);
+err_fclk:
+ clk_put(hclk);
+
+ return -ENOENT;
+}
+
+static struct subsys_interface s3c2412_cpufreq_interface = {
+ .name = "s3c2412_cpufreq",
+ .subsys = &s3c2412_subsys,
+ .add_dev = s3c2412_cpufreq_add,
+};
+
+static int s3c2412_cpufreq_init(void)
+{
+ return subsys_interface_register(&s3c2412_cpufreq_interface);
+}
+arch_initcall(s3c2412_cpufreq_init);