summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/s3c2412-cpufreq.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-02 14:33:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-02 14:33:21 -0700
commit0bf6a210a43f7118d858806200127e421649fc4e (patch)
tree9a17d88ebd1b9bc693fba7f39c12123dec96e930 /drivers/cpufreq/s3c2412-cpufreq.c
parentee1a8d402e7e204d57fb108aa40003b6d1633036 (diff)
parent5c913a9a9772f4b434aaea7328836419287b5d1c (diff)
downloadblackbird-op-linux-0bf6a210a43f7118d858806200127e421649fc4e.tar.gz
blackbird-op-linux-0bf6a210a43f7118d858806200127e421649fc4e.zip
Merge tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver specific changes from Arnd Bergmann: "These changes are all driver specific and cross over between arm-soc contents and some other subsystem, in these cases cpufreq, crypto, dma, pinctrl, mailbox and usb, and the subsystem owners agreed to have these changes merged through arm-soc. As we proceed to untangle the dependencies between platform code and driver code, the amount of changes in this category is fortunately shrinking, for 3.11 we have 16 branches here and 101 non-merge changesets, the majority of which are for the stedma40 dma engine driver used in the ux500 platform. Cleaning up that code touches multiple subsystems, but gets rid of the dependency in the end. The mailbox code moved out from mach-omap2 to drivers/mailbox is an intermediate step and is still omap specific at the moment. Patches exist to generalize the subsystem and add other drivers with the same API, but those did not make it for 3.11." * tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (101 commits) crypto: ux500: use dmaengine_submit API crypto: ux500: use dmaengine_prep_slave_sg API crypto: ux500: use dmaengine_device_control API crypto: ux500/crypt: add missing __iomem qualifiers crypto: ux500/hash: add missing static qualifiers crypto: ux500/hash: use readl on iomem addresses dmaengine: ste_dma40: Declare memcpy config as static ARM: ux500: Remove mop500_snowball_ethernet_clock_enable() ARM: ux500: Correct the EN_3v3 regulator's on/off GPIO ARM: ux500: Provide a AB8500 GPIO Device Tree node gpio: rcar: fix gpio_rcar_of_table gpio-rcar: Remove #ifdef CONFIG_OF around OF-specific sections gpio-rcar: Reference core gpio documentation in the DT bindings clk: exynos5250: Add enum entries for divider clock of i2s1 and i2s2 ARM: dts: Update Samsung I2S documentation ARM: dts: add clock provider information for i2s controllers in Exynos5250 ARM: dts: add Exynos audio subsystem clock controller node clk: samsung: register audio subsystem clocks using common clock framework ARM: dts: use #include for all device trees for Samsung pinctrl: s3c24xx: use correct header for chained_irq functions ...
Diffstat (limited to 'drivers/cpufreq/s3c2412-cpufreq.c')
-rw-r--r--drivers/cpufreq/s3c2412-cpufreq.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/drivers/cpufreq/s3c2412-cpufreq.c b/drivers/cpufreq/s3c2412-cpufreq.c
new file mode 100644
index 000000000000..4645b4898996
--- /dev/null
+++ b/drivers/cpufreq/s3c2412-cpufreq.c
@@ -0,0 +1,257 @@
+/*
+ * Copyright 2008 Simtec Electronics
+ * http://armlinux.simtec.co.uk/
+ * Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C2412 CPU Frequency scalling
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#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 <asm/mach/arch.h>
+#include <asm/mach/map.h>
+
+#include <mach/regs-clock.h>
+#include <mach/s3c2412.h>
+
+#include <plat/cpu.h>
+#include <plat/clock.h>
+#include <plat/cpu-freq-core.h>
+
+/* 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 = __raw_readl(S3C2410_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);
+ __raw_writel(clkdiv, S3C2410_CLKDIVN);
+
+ clk_set_parent(armclk, cfg->divs.dvs ? hclk : fclk);
+}
+
+static void s3c2412_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
+{
+ struct s3c_cpufreq_board *board = cfg->board;
+ unsigned long refresh;
+
+ s3c_freq_dbg("%s: refresh %u ns, hclk %lu\n", __func__,
+ board->refresh, cfg->freq.hclk);
+
+ /* Reduce both the refresh time (in ns) and the frequency (in MHz)
+ * by 10 each to ensure that we do not overflow 32 bit numbers. This
+ * should work for HCLK up to 133MHz and refresh period up to 30usec.
+ */
+
+ refresh = (board->refresh / 10);
+ refresh *= (cfg->freq.hclk / 100);
+ refresh /= (1 * 1000 * 1000); /* 10^6 */
+
+ s3c_freq_dbg("%s: setting refresh 0x%08lx\n", __func__, refresh);
+ __raw_writel(refresh, S3C2412_REFRESH);
+}
+
+/* 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,
+
+ .resume_clocks = s3c2412_setup_clocks,
+
+ .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)) {
+ printk(KERN_ERR "%s: cannot find hclk clock\n", __func__);
+ return -ENOENT;
+ }
+
+ fclk = clk_get(NULL, "fclk");
+ if (IS_ERR(fclk)) {
+ printk(KERN_ERR "%s: cannot find fclk clock\n", __func__);
+ goto err_fclk;
+ }
+
+ fclk_rate = clk_get_rate(fclk);
+ if (fclk_rate > 200000000) {
+ printk(KERN_INFO
+ "%s: fclk %ld MHz, assuming 266MHz capable part\n",
+ __func__, 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)) {
+ printk(KERN_ERR "%s: cannot find arm clock\n", __func__);
+ goto err_armclk;
+ }
+
+ xtal = clk_get(NULL, "xtal");
+ if (IS_ERR(xtal)) {
+ printk(KERN_ERR "%s: cannot find xtal clock\n", __func__);
+ 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);
OpenPOWER on IntegriCloud