arm: msm: add cpu frequency controls

This adds acpuclock-arm11.c from Google. This provides control
over the cpu frequency for arm11 cpu's.

This has shared authorship between Google, and Qualcomm. Most
of it was written by Mike Chan at Google.

Signed-off-by: Daniel Walker <dwalker@codeaurora.org>

1 files changed, 523 insertions, 0 deletions

diff --git a/arch/arm/mach-msm/acpuclock-arm11.c b/arch/arm/mach-msm/acpuclock-arm11.c
new file mode 100644
index 00000000000..f9c9035bd9b
--- /dev/null
+++ b/arch/arm/mach-msm/acpuclock-arm11.c
@@ -0,0 +1,523 @@
+/* arch/arm/mach-msm/acpuclock.c
+ *
+ * MSM architecture clock driver
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2007 QUALCOMM Incorporated
+ * Author: San Mehat <san@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/mutex.h>
+#include <linux/io.h>
+#include <mach/board.h>
+#include <mach/msm_iomap.h>
+
+#include "proc_comm.h"
+#include "acpuclock.h"
+
+
+#define A11S_CLK_CNTL_ADDR (MSM_CSR_BASE + 0x100)
+#define A11S_CLK_SEL_ADDR (MSM_CSR_BASE + 0x104)
+#define A11S_VDD_SVS_PLEVEL_ADDR (MSM_CSR_BASE + 0x124)
+
+/*
+ * ARM11 clock configuration for specific ACPU speeds
+ */
+
+#define ACPU_PLL_TCXO	-1
+#define ACPU_PLL_0	0
+#define ACPU_PLL_1	1
+#define ACPU_PLL_2	2
+#define ACPU_PLL_3	3
+
+#define PERF_SWITCH_DEBUG 0
+#define PERF_SWITCH_STEP_DEBUG 0
+
+struct clock_state
+{
+	struct clkctl_acpu_speed	*current_speed;
+	struct mutex			lock;
+	uint32_t			acpu_switch_time_us;
+	uint32_t			max_speed_delta_khz;
+	uint32_t			vdd_switch_time_us;
+	unsigned long			power_collapse_khz;
+	unsigned long			wait_for_irq_khz;
+};
+
+static struct clk *ebi1_clk;
+static struct clock_state drv_state = { 0 };
+
+static void __init acpuclk_init(void);
+
+/* MSM7201A Levels 3-6 all correspond to 1.2V, level 7 corresponds to 1.325V. */
+enum {
+	VDD_0 = 0,
+	VDD_1 = 1,
+	VDD_2 = 2,
+	VDD_3 = 3,
+	VDD_4 = 3,
+	VDD_5 = 3,
+	VDD_6 = 3,
+	VDD_7 = 7,
+	VDD_END
+};
+
+struct clkctl_acpu_speed {
+	unsigned int	a11clk_khz;
+	int		pll;
+	unsigned int	a11clk_src_sel;
+	unsigned int	a11clk_src_div;
+	unsigned int	ahbclk_khz;
+	unsigned int	ahbclk_div;
+	int		vdd;
+	unsigned int 	axiclk_khz;
+	unsigned long	lpj; /* loops_per_jiffy */
+/* Index in acpu_freq_tbl[] for steppings. */
+	short		down;
+	short		up;
+};
+
+/*
+ * ACPU speed table. Complete table is shown but certain speeds are commented
+ * out to optimized speed switching. Initalize loops_per_jiffy to 0.
+ *
+ * Table stepping up/down is optimized for 256mhz jumps while staying on the
+ * same PLL.
+ */
+#if (0)
+static struct clkctl_acpu_speed  acpu_freq_tbl[] = {
+	{ 19200, ACPU_PLL_TCXO, 0, 0, 19200, 0, VDD_0, 30720, 0, 0, 8 },
+	{ 61440, ACPU_PLL_0,  4, 3, 61440,  0, VDD_0, 30720,  0, 0, 8 },
+	{ 81920, ACPU_PLL_0,  4, 2, 40960,  1, VDD_0, 61440,  0, 0, 8 },
+	{ 96000, ACPU_PLL_1,  1, 7, 48000,  1, VDD_0, 61440,  0, 0, 9 },
+	{ 122880, ACPU_PLL_0, 4, 1, 61440,  1, VDD_3, 61440,  0, 0, 8 },
+	{ 128000, ACPU_PLL_1, 1, 5, 64000,  1, VDD_3, 61440,  0, 0, 12 },
+	{ 176000, ACPU_PLL_2, 2, 5, 88000,  1, VDD_3, 61440,  0, 0, 11 },
+	{ 192000, ACPU_PLL_1, 1, 3, 64000,  2, VDD_3, 61440,  0, 0, 12 },
+	{ 245760, ACPU_PLL_0, 4, 0, 81920,  2, VDD_4, 61440,  0, 0, 12 },
+	{ 256000, ACPU_PLL_1, 1, 2, 128000, 2, VDD_5, 128000, 0, 0, 12 },
+	{ 264000, ACPU_PLL_2, 2, 3, 88000,  2, VDD_5, 128000, 0, 6, 13 },
+	{ 352000, ACPU_PLL_2, 2, 2, 88000,  3, VDD_5, 128000, 0, 6, 13 },
+	{ 384000, ACPU_PLL_1, 1, 1, 128000, 2, VDD_6, 128000, 0, 5, -1 },
+	{ 528000, ACPU_PLL_2, 2, 1, 132000, 3, VDD_7, 128000, 0, 11, -1 },
+	{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
+};
+#else /* Table of freq we currently use. */
+static struct clkctl_acpu_speed  acpu_freq_tbl[] = {
+	{ 19200, ACPU_PLL_TCXO, 0, 0, 19200, 0, VDD_0, 30720, 0, 0, 4 },
+	{ 122880, ACPU_PLL_0, 4, 1, 61440, 1, VDD_3, 61440, 0, 0, 4 },
+	{ 128000, ACPU_PLL_1, 1, 5, 64000, 1, VDD_3, 61440, 0, 0, 6 },
+	{ 176000, ACPU_PLL_2, 2, 5, 88000, 1, VDD_3, 61440, 0, 0, 5 },
+	{ 245760, ACPU_PLL_0, 4, 0, 81920, 2, VDD_4, 61440, 0, 0, 5 },
+	{ 352000, ACPU_PLL_2, 2, 2, 88000, 3, VDD_5, 128000, 0, 3, 7 },
+	{ 384000, ACPU_PLL_1, 1, 1, 128000, 2, VDD_6, 128000, 0, 2, -1 },
+	{ 528000, ACPU_PLL_2, 2, 1, 132000, 3, VDD_7, 128000, 0, 5, -1 },
+	{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
+};
+#endif
+
+static struct cpufreq_frequency_table freq_table[] = {
+	{ 0, 122880 },
+	{ 1, 128000 },
+	{ 2, 245760 },
+	{ 3, 384000 },
+	{ 4, 528000 },
+	{ 5, CPUFREQ_TABLE_END },
+};
+
+static int pc_pll_request(unsigned id, unsigned on)
+{
+	int res;
+	on = !!on;
+
+#if PERF_SWITCH_DEBUG
+	if (on)
+		printk(KERN_DEBUG "Enabling PLL %d\n", id);
+	else
+		printk(KERN_DEBUG "Disabling PLL %d\n", id);
+#endif
+
+	res = msm_proc_comm(PCOM_CLKCTL_RPC_PLL_REQUEST, &id, &on);
+	if (res < 0)
+		return res;
+
+#if PERF_SWITCH_DEBUG
+	if (on)
+		printk(KERN_DEBUG "PLL %d enabled\n", id);
+	else
+		printk(KERN_DEBUG "PLL %d disabled\n", id);
+#endif
+	return res;
+}
+
+
+/*----------------------------------------------------------------------------
+ * ARM11 'owned' clock control
+ *---------------------------------------------------------------------------*/
+
+unsigned long acpuclk_power_collapse(void) {
+	int ret = acpuclk_get_rate();
+	ret *= 1000;
+	if (ret > drv_state.power_collapse_khz)
+		acpuclk_set_rate(drv_state.power_collapse_khz, 1);
+	return ret;
+}
+
+unsigned long acpuclk_get_wfi_rate(void)
+{
+	return drv_state.wait_for_irq_khz;
+}
+
+unsigned long acpuclk_wait_for_irq(void) {
+	int ret = acpuclk_get_rate();
+	ret *= 1000;
+	if (ret > drv_state.wait_for_irq_khz)
+		acpuclk_set_rate(drv_state.wait_for_irq_khz, 1);
+	return ret;
+}
+
+static int acpuclk_set_vdd_level(int vdd)
+{
+	uint32_t current_vdd;
+
+	current_vdd = readl(A11S_VDD_SVS_PLEVEL_ADDR) & 0x07;
+
+#if PERF_SWITCH_DEBUG
+	printk(KERN_DEBUG "acpuclock: Switching VDD from %u -> %d\n",
+	       current_vdd, vdd);
+#endif
+	writel((1 << 7) | (vdd << 3), A11S_VDD_SVS_PLEVEL_ADDR);
+	udelay(drv_state.vdd_switch_time_us);
+	if ((readl(A11S_VDD_SVS_PLEVEL_ADDR) & 0x7) != vdd) {
+#if PERF_SWITCH_DEBUG
+		printk(KERN_ERR "acpuclock: VDD set failed\n");
+#endif
+		return -EIO;
+	}
+
+#if PERF_SWITCH_DEBUG
+	printk(KERN_DEBUG "acpuclock: VDD switched\n");
+#endif
+	return 0;
+}
+
+/* Set proper dividers for the given clock speed. */
+static void acpuclk_set_div(const struct clkctl_acpu_speed *hunt_s) {
+	uint32_t reg_clkctl, reg_clksel, clk_div;
+
+	/* AHB_CLK_DIV */
+	clk_div = (readl(A11S_CLK_SEL_ADDR) >> 1) & 0x03;
+	/*
+	 * If the new clock divider is higher than the previous, then
+	 * program the divider before switching the clock
+	 */
+	if (hunt_s->ahbclk_div > clk_div) {
+		reg_clksel = readl(A11S_CLK_SEL_ADDR);
+		reg_clksel &= ~(0x3 << 1);
+		reg_clksel |= (hunt_s->ahbclk_div << 1);
+		writel(reg_clksel, A11S_CLK_SEL_ADDR);
+	}
+	if ((readl(A11S_CLK_SEL_ADDR) & 0x01) == 0) {
+		/* SRC0 */
+
+		/* Program clock source */
+		reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
+		reg_clkctl &= ~(0x07 << 4);
+		reg_clkctl |= (hunt_s->a11clk_src_sel << 4);
+		writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
+
+		/* Program clock divider */
+		reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
+		reg_clkctl &= ~0xf;
+		reg_clkctl |= hunt_s->a11clk_src_div;
+		writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
+
+		/* Program clock source selection */
+		reg_clksel = readl(A11S_CLK_SEL_ADDR);
+		reg_clksel |= 1; /* CLK_SEL_SRC1NO  == SRC1 */
+		writel(reg_clksel, A11S_CLK_SEL_ADDR);
+	} else {
+		/* SRC1 */
+
+		/* Program clock source */
+		reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
+		reg_clkctl &= ~(0x07 << 12);
+		reg_clkctl |= (hunt_s->a11clk_src_sel << 12);
+		writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
+
+		/* Program clock divider */
+		reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
+		reg_clkctl &= ~(0xf << 8);
+		reg_clkctl |= (hunt_s->a11clk_src_div << 8);
+		writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
+
+		/* Program clock source selection */
+		reg_clksel = readl(A11S_CLK_SEL_ADDR);
+		reg_clksel &= ~1; /* CLK_SEL_SRC1NO  == SRC0 */
+		writel(reg_clksel, A11S_CLK_SEL_ADDR);
+	}
+
+	/*
+	 * If the new clock divider is lower than the previous, then
+	 * program the divider after switching the clock
+	 */
+	if (hunt_s->ahbclk_div < clk_div) {
+		reg_clksel = readl(A11S_CLK_SEL_ADDR);
+		reg_clksel &= ~(0x3 << 1);
+		reg_clksel |= (hunt_s->ahbclk_div << 1);
+		writel(reg_clksel, A11S_CLK_SEL_ADDR);
+	}
+}
+
+int acpuclk_set_rate(unsigned long rate, int for_power_collapse)
+{
+	uint32_t reg_clkctl;
+	struct clkctl_acpu_speed *cur_s, *tgt_s, *strt_s;
+	int rc = 0;
+	unsigned int plls_enabled = 0, pll;
+
+	strt_s = cur_s = drv_state.current_speed;
+
+	WARN_ONCE(cur_s == NULL, "acpuclk_set_rate: not initialized\n");
+	if (cur_s == NULL)
+		return -ENOENT;
+
+	if (rate == (cur_s->a11clk_khz * 1000))
+		return 0;
+
+	for (tgt_s = acpu_freq_tbl; tgt_s->a11clk_khz != 0; tgt_s++) {
+		if (tgt_s->a11clk_khz == (rate / 1000))
+			break;
+	}
+
+	if (tgt_s->a11clk_khz == 0)
+		return -EINVAL;
+
+	/* Choose the highest speed speed at or below 'rate' with same PLL. */
+	if (for_power_collapse && tgt_s->a11clk_khz < cur_s->a11clk_khz) {
+		while (tgt_s->pll != ACPU_PLL_TCXO && tgt_s->pll != cur_s->pll)
+			tgt_s--;
+	}
+
+	if (strt_s->pll != ACPU_PLL_TCXO)
+		plls_enabled |= 1 << strt_s->pll;
+
+	if (!for_power_collapse) {
+		mutex_lock(&drv_state.lock);
+		if (strt_s->pll != tgt_s->pll && tgt_s->pll != ACPU_PLL_TCXO) {
+			rc = pc_pll_request(tgt_s->pll, 1);
+			if (rc < 0) {
+				pr_err("PLL%d enable failed (%d)\n",
+					tgt_s->pll, rc);
+				goto out;
+			}
+			plls_enabled |= 1 << tgt_s->pll;
+		}
+		/* Increase VDD if needed. */
+		if (tgt_s->vdd > cur_s->vdd) {
+			if ((rc = acpuclk_set_vdd_level(tgt_s->vdd)) < 0) {
+				printk(KERN_ERR "Unable to switch ACPU vdd\n");
+				goto out;
+			}
+		}
+	}
+
+	/* Set wait states for CPU inbetween frequency changes */
+	reg_clkctl = readl(A11S_CLK_CNTL_ADDR);
+	reg_clkctl |= (100 << 16); /* set WT_ST_CNT */
+	writel(reg_clkctl, A11S_CLK_CNTL_ADDR);
+
+#if PERF_SWITCH_DEBUG
+	printk(KERN_INFO "acpuclock: Switching from ACPU rate %u -> %u\n",
+	       strt_s->a11clk_khz * 1000, tgt_s->a11clk_khz * 1000);
+#endif
+
+	while (cur_s != tgt_s) {
+		/*
+		 * Always jump to target freq if within 256mhz, regulardless of
+		 * PLL. If differnece is greater, use the predefinied
+		 * steppings in the table.
+		 */
+		int d = abs((int)(cur_s->a11clk_khz - tgt_s->a11clk_khz));
+		if (d > drv_state.max_speed_delta_khz) {
+			/* Step up or down depending on target vs current. */
+			int clk_index = tgt_s->a11clk_khz > cur_s->a11clk_khz ?
+				cur_s->up : cur_s->down;
+			if (clk_index < 0) { /* This should not happen. */
+				printk(KERN_ERR "cur:%u target: %u\n",
+					cur_s->a11clk_khz, tgt_s->a11clk_khz);
+				rc = -EINVAL;
+				goto out;
+			}
+			cur_s = &acpu_freq_tbl[clk_index];
+		} else {
+			cur_s = tgt_s;
+		}
+#if PERF_SWITCH_STEP_DEBUG
+		printk(KERN_DEBUG "%s: STEP khz = %u, pll = %d\n",
+			__FUNCTION__, cur_s->a11clk_khz, cur_s->pll);
+#endif
+		if (!for_power_collapse&& cur_s->pll != ACPU_PLL_TCXO
+		    && !(plls_enabled & (1 << cur_s->pll))) {
+			rc = pc_pll_request(cur_s->pll, 1);
+			if (rc < 0) {
+				pr_err("PLL%d enable failed (%d)\n",
+					cur_s->pll, rc);
+				goto out;
+			}
+			plls_enabled |= 1 << cur_s->pll;
+		}
+
+		acpuclk_set_div(cur_s);
+		drv_state.current_speed = cur_s;
+		/* Re-adjust lpj for the new clock speed. */
+		loops_per_jiffy = cur_s->lpj;
+		udelay(drv_state.acpu_switch_time_us);
+	}
+
+	/* Nothing else to do for power collapse. */
+	if (for_power_collapse)
+		return 0;
+
+	/* Disable PLLs we are not using anymore. */
+	plls_enabled &= ~(1 << tgt_s->pll);
+	for (pll = ACPU_PLL_0; pll <= ACPU_PLL_2; pll++)
+		if (plls_enabled & (1 << pll)) {
+			rc = pc_pll_request(pll, 0);
+			if (rc < 0) {
+				pr_err("PLL%d disable failed (%d)\n", pll, rc);
+				goto out;
+			}
+		}
+
+	/* Change the AXI bus frequency if we can. */
+	if (strt_s->axiclk_khz != tgt_s->axiclk_khz) {
+		rc = clk_set_rate(ebi1_clk, tgt_s->axiclk_khz * 1000);
+		if (rc < 0)
+			pr_err("Setting AXI min rate failed!\n");
+	}
+
+	/* Drop VDD level if we can. */
+	if (tgt_s->vdd < strt_s->vdd) {
+		if (acpuclk_set_vdd_level(tgt_s->vdd) < 0)
+			printk(KERN_ERR "acpuclock: Unable to drop ACPU vdd\n");
+	}
+
+#if PERF_SWITCH_DEBUG
+	printk(KERN_DEBUG "%s: ACPU speed change complete\n", __FUNCTION__);
+#endif
+out:
+	if (!for_power_collapse)
+		mutex_unlock(&drv_state.lock);
+	return rc;
+}
+
+static void __init acpuclk_init(void)
+{
+	struct clkctl_acpu_speed *speed;
+	uint32_t div, sel;
+	int rc;
+
+	/*
+	 * Determine the rate of ACPU clock
+	 */
+
+	if (!(readl(A11S_CLK_SEL_ADDR) & 0x01)) { /* CLK_SEL_SRC1N0 */
+		/* CLK_SRC0_SEL */
+		sel = (readl(A11S_CLK_CNTL_ADDR) >> 12) & 0x7;
+		/* CLK_SRC0_DIV */
+		div = (readl(A11S_CLK_CNTL_ADDR) >> 8) & 0x0f;
+	} else {
+		/* CLK_SRC1_SEL */
+		sel = (readl(A11S_CLK_CNTL_ADDR) >> 4) & 0x07;
+		/* CLK_SRC1_DIV */
+		div = readl(A11S_CLK_CNTL_ADDR) & 0x0f;
+	}
+
+	for (speed = acpu_freq_tbl; speed->a11clk_khz != 0; speed++) {
+		if (speed->a11clk_src_sel == sel
+		 && (speed->a11clk_src_div == div))
+			break;
+	}
+	if (speed->a11clk_khz == 0) {
+		printk(KERN_WARNING "Warning - ACPU clock reports invalid speed\n");
+		return;
+	}
+
+	drv_state.current_speed = speed;
+
+	rc = clk_set_rate(ebi1_clk, speed->axiclk_khz * 1000);
+	if (rc < 0)
+		pr_err("Setting AXI min rate failed!\n");
+
+	printk(KERN_INFO "ACPU running at %d KHz\n", speed->a11clk_khz);
+}
+
+unsigned long acpuclk_get_rate(void)
+{
+	WARN_ONCE(drv_state.current_speed == NULL,
+		  "acpuclk_get_rate: not initialized\n");
+	if (drv_state.current_speed)
+		return drv_state.current_speed->a11clk_khz;
+	else
+		return 0;
+}
+
+uint32_t acpuclk_get_switch_time(void)
+{
+	return drv_state.acpu_switch_time_us;
+}
+
+/*----------------------------------------------------------------------------
+ * Clock driver initialization
+ *---------------------------------------------------------------------------*/
+
+/* Initalize the lpj field in the acpu_freq_tbl. */
+static void __init lpj_init(void)
+{
+	int i;
+	const struct clkctl_acpu_speed *base_clk = drv_state.current_speed;
+	for (i = 0; acpu_freq_tbl[i].a11clk_khz; i++) {
+		acpu_freq_tbl[i].lpj = cpufreq_scale(loops_per_jiffy,
+						base_clk->a11clk_khz,
+						acpu_freq_tbl[i].a11clk_khz);
+	}
+}
+
+void __init msm_acpu_clock_init(struct msm_acpu_clock_platform_data *clkdata)
+{
+	pr_info("acpu_clock_init()\n");
+
+	ebi1_clk = clk_get(NULL, "ebi1_clk");
+
+	mutex_init(&drv_state.lock);
+	drv_state.acpu_switch_time_us = clkdata->acpu_switch_time_us;
+	drv_state.max_speed_delta_khz = clkdata->max_speed_delta_khz;
+	drv_state.vdd_switch_time_us = clkdata->vdd_switch_time_us;
+	drv_state.power_collapse_khz = clkdata->power_collapse_khz;
+	drv_state.wait_for_irq_khz = clkdata->wait_for_irq_khz;
+	acpuclk_init();
+	lpj_init();
+#ifdef CONFIG_CPU_FREQ_TABLE
+	cpufreq_frequency_table_get_attr(freq_table, smp_processor_id());
+#endif
+}