OMAP2+: voltage: split voltage controller (VC) code into dedicated layer

As part of the voltage layer cleanup, split out VC specific code into
a dedicated VC layer.  This patch primarily just moves VC code from
voltage.c into vc.c, and adds prototypes to vc.h.

No functional changes.

For readability, each function was given a local 'vc' pointer:

    struct omap_vc_instance_data *vc = voltdm->vdd->vc_data;

and a global replace of s/vdd->vc_data/vc/ was done.

Also vc_init was renamed to vc_init_channel to reflect that this is
per-VC channel initializtion.

Signed-off-by: Kevin Hilman <khilman@ti.com>

arch/arm/mach-omap2/Makefile

@@ -90,7 +90,7 @@ obj-$(CONFIG_ARCH_OMAP4)		+= prcm.o cm2xxx_3xxx.o cminst44xx.o \
 
 # OMAP voltage domains
 ifeq ($(CONFIG_PM),y)
-voltagedomain-common			:= voltage.o
+voltagedomain-common			:= voltage.o vc.o
 obj-$(CONFIG_ARCH_OMAP2)		+= $(voltagedomain-common) \
 					   voltagedomains2xxx_data.o
 obj-$(CONFIG_ARCH_OMAP3)		+= $(voltagedomain-common) \

arch/arm/mach-omap2/vc.c

@@ -0,0 +1,285 @@
+/*
+ * OMAP Voltage Controller (VC) interface
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+
+#include <plat/cpu.h>
+
+#include "voltage.h"
+#include "vc.h"
+#include "prm-regbits-34xx.h"
+#include "prm-regbits-44xx.h"
+#include "prm44xx.h"
+
+/* Voltage scale and accessory APIs */
+int omap_vc_pre_scale(struct voltagedomain *voltdm,
+		      unsigned long target_volt,
+		      u8 *target_vsel, u8 *current_vsel)
+{
+	struct omap_vc_instance_data *vc = voltdm->vdd->vc_data;
+	struct omap_vdd_info *vdd = voltdm->vdd;
+	struct omap_volt_data *volt_data;
+	const struct omap_vc_common_data *vc_common;
+	const struct omap_vp_common_data *vp_common;
+	u32 vc_cmdval, vp_errgain_val;
+
+	vc_common = vc->vc_common;
+	vp_common = vdd->vp_data->vp_common;
+
+	/* Check if sufficient pmic info is available for this vdd */
+	if (!vdd->pmic_info) {
+		pr_err("%s: Insufficient pmic info to scale the vdd_%s\n",
+			__func__, voltdm->name);
+		return -EINVAL;
+	}
+
+	if (!vdd->pmic_info->uv_to_vsel) {
+		pr_err("%s: PMIC function to convert voltage in uV to"
+			"vsel not registered. Hence unable to scale voltage"
+			"for vdd_%s\n", __func__, voltdm->name);
+		return -ENODATA;
+	}
+
+	if (!vdd->read_reg || !vdd->write_reg) {
+		pr_err("%s: No read/write API for accessing vdd_%s regs\n",
+			__func__, voltdm->name);
+		return -EINVAL;
+	}
+
+	/* Get volt_data corresponding to target_volt */
+	volt_data = omap_voltage_get_voltdata(voltdm, target_volt);
+	if (IS_ERR(volt_data))
+		volt_data = NULL;
+
+	*target_vsel = vdd->pmic_info->uv_to_vsel(target_volt);
+	*current_vsel = vdd->read_reg(vdd->vp_data->vp_common->prm_mod, vdd->vp_data->voltage);
+
+	/* Setting the ON voltage to the new target voltage */
+	vc_cmdval = vdd->read_reg(vc->vc_common->prm_mod, vc->cmdval_reg);
+	vc_cmdval &= ~vc_common->cmd_on_mask;
+	vc_cmdval |= (*target_vsel << vc_common->cmd_on_shift);
+	vdd->write_reg(vc_cmdval, vc->vc_common->prm_mod, vc->cmdval_reg);
+
+	/* Setting vp errorgain based on the voltage */
+	if (volt_data) {
+		vp_errgain_val = vdd->read_reg(vdd->vp_data->vp_common->prm_mod,
+					       vdd->vp_data->vpconfig);
+		vdd->vp_rt_data.vpconfig_errorgain = volt_data->vp_errgain;
+		vp_errgain_val &= ~vp_common->vpconfig_errorgain_mask;
+		vp_errgain_val |= vdd->vp_rt_data.vpconfig_errorgain <<
+			vp_common->vpconfig_errorgain_shift;
+		vdd->write_reg(vp_errgain_val, vdd->vp_data->vp_common->prm_mod,
+			       vdd->vp_data->vpconfig);
+	}
+
+	return 0;
+}
+
+void omap_vc_post_scale(struct voltagedomain *voltdm,
+			unsigned long target_volt,
+			u8 target_vsel, u8 current_vsel)
+{
+	struct omap_vdd_info *vdd = voltdm->vdd;
+	u32 smps_steps = 0, smps_delay = 0;
+
+	smps_steps = abs(target_vsel - current_vsel);
+	/* SMPS slew rate / step size. 2us added as buffer. */
+	smps_delay = ((smps_steps * vdd->pmic_info->step_size) /
+			vdd->pmic_info->slew_rate) + 2;
+	udelay(smps_delay);
+
+	vdd->curr_volt = target_volt;
+}
+
+/* vc_bypass_scale_voltage - VC bypass method of voltage scaling */
+int omap_vc_bypass_scale_voltage(struct voltagedomain *voltdm,
+				 unsigned long target_volt)
+{
+	struct omap_vc_instance_data *vc = voltdm->vdd->vc_data;
+	struct omap_vdd_info *vdd = voltdm->vdd;
+	u32 loop_cnt = 0, retries_cnt = 0;
+	u32 vc_valid, vc_bypass_val_reg, vc_bypass_value;
+	u8 target_vsel, current_vsel;
+	int ret;
+
+	ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, &current_vsel);
+	if (ret)
+		return ret;
+
+	vc_valid = vc->vc_common->valid;
+	vc_bypass_val_reg = vc->vc_common->bypass_val_reg;
+	vc_bypass_value = (target_vsel << vc->vc_common->data_shift) |
+			(vdd->pmic_info->pmic_reg <<
+			vc->vc_common->regaddr_shift) |
+			(vdd->pmic_info->i2c_slave_addr <<
+			vc->vc_common->slaveaddr_shift);
+
+	vdd->write_reg(vc_bypass_value, vc->vc_common->prm_mod, vc_bypass_val_reg);
+	vdd->write_reg(vc_bypass_value | vc_valid, vc->vc_common->prm_mod,
+		       vc_bypass_val_reg);
+
+	vc_bypass_value = vdd->read_reg(vc->vc_common->prm_mod, vc_bypass_val_reg);
+	/*
+	 * Loop till the bypass command is acknowledged from the SMPS.
+	 * NOTE: This is legacy code. The loop count and retry count needs
+	 * to be revisited.
+	 */
+	while (!(vc_bypass_value & vc_valid)) {
+		loop_cnt++;
+
+		if (retries_cnt > 10) {
+			pr_warning("%s: Retry count exceeded\n", __func__);
+			return -ETIMEDOUT;
+		}
+
+		if (loop_cnt > 50) {
+			retries_cnt++;
+			loop_cnt = 0;
+			udelay(10);
+		}
+		vc_bypass_value = vdd->read_reg(vc->vc_common->prm_mod,
+						vc_bypass_val_reg);
+	}
+
+	omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
+	return 0;
+}
+
+static void __init omap3_vfsm_init(struct voltagedomain *voltdm)
+{
+	struct omap_vc_instance_data *vc = voltdm->vdd->vc_data;
+	struct omap_vdd_info *vdd = voltdm->vdd;
+
+	/*
+	 * Voltage Manager FSM parameters init
+	 * XXX This data should be passed in from the board file
+	 */
+	vdd->write_reg(OMAP3_CLKSETUP, vc->vc_common->prm_mod, OMAP3_PRM_CLKSETUP_OFFSET);
+	vdd->write_reg(OMAP3_VOLTOFFSET, vc->vc_common->prm_mod,
+		       OMAP3_PRM_VOLTOFFSET_OFFSET);
+	vdd->write_reg(OMAP3_VOLTSETUP2, vc->vc_common->prm_mod,
+		       OMAP3_PRM_VOLTSETUP2_OFFSET);
+}
+
+static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
+{
+	struct omap_vc_instance_data *vc = voltdm->vdd->vc_data;
+	struct omap_vdd_info *vdd = voltdm->vdd;
+	static bool is_initialized;
+	u8 on_vsel, onlp_vsel, ret_vsel, off_vsel;
+	u32 vc_val;
+
+	if (is_initialized)
+		return;
+
+	/* Set up the on, inactive, retention and off voltage */
+	on_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->on_volt);
+	onlp_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->onlp_volt);
+	ret_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->ret_volt);
+	off_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->off_volt);
+	vc_val	= ((on_vsel << vc->vc_common->cmd_on_shift) |
+		(onlp_vsel << vc->vc_common->cmd_onlp_shift) |
+		(ret_vsel << vc->vc_common->cmd_ret_shift) |
+		(off_vsel << vc->vc_common->cmd_off_shift));
+	vdd->write_reg(vc_val, vc->vc_common->prm_mod, vc->cmdval_reg);
+
+	/*
+	 * Generic VC parameters init
+	 * XXX This data should be abstracted out
+	 */
+	vdd->write_reg(OMAP3430_CMD1_MASK | OMAP3430_RAV1_MASK, vc->vc_common->prm_mod,
+			OMAP3_PRM_VC_CH_CONF_OFFSET);
+	vdd->write_reg(OMAP3430_MCODE_SHIFT | OMAP3430_HSEN_MASK, vc->vc_common->prm_mod,
+			OMAP3_PRM_VC_I2C_CFG_OFFSET);
+
+	omap3_vfsm_init(voltdm);
+
+	is_initialized = true;
+}
+
+
+/* OMAP4 specific voltage init functions */
+static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
+{
+	struct omap_vc_instance_data *vc = voltdm->vdd->vc_data;
+	struct omap_vdd_info *vdd = voltdm->vdd;
+	static bool is_initialized;
+	u32 vc_val;
+
+	if (is_initialized)
+		return;
+
+	/* TODO: Configure setup times and CMD_VAL values*/
+
+	/*
+	 * Generic VC parameters init
+	 * XXX This data should be abstracted out
+	 */
+	vc_val = (OMAP4430_RAV_VDD_MPU_L_MASK | OMAP4430_CMD_VDD_MPU_L_MASK |
+		  OMAP4430_RAV_VDD_IVA_L_MASK | OMAP4430_CMD_VDD_IVA_L_MASK |
+		  OMAP4430_RAV_VDD_CORE_L_MASK | OMAP4430_CMD_VDD_CORE_L_MASK);
+	vdd->write_reg(vc_val, vc->vc_common->prm_mod, OMAP4_PRM_VC_CFG_CHANNEL_OFFSET);
+
+	/* XXX These are magic numbers and do not belong! */
+	vc_val = (0x60 << OMAP4430_SCLL_SHIFT | 0x26 << OMAP4430_SCLH_SHIFT);
+	vdd->write_reg(vc_val, vc->vc_common->prm_mod, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
+
+	is_initialized = true;
+}
+
+void __init omap_vc_init_channel(struct voltagedomain *voltdm)
+{
+	struct omap_vc_instance_data *vc = voltdm->vdd->vc_data;
+	struct omap_vdd_info *vdd = voltdm->vdd;
+	u32 vc_val;
+
+	if (!vdd->pmic_info || !vdd->pmic_info->uv_to_vsel) {
+		pr_err("%s: PMIC info requried to configure vc for"
+			"vdd_%s not populated.Hence cannot initialize vc\n",
+			__func__, voltdm->name);
+		return;
+	}
+
+	if (!vdd->read_reg || !vdd->write_reg) {
+		pr_err("%s: No read/write API for accessing vdd_%s regs\n",
+			__func__, voltdm->name);
+		return;
+	}
+
+	/* Set up the SMPS_SA(i2c slave address in VC */
+	vc_val = vdd->read_reg(vc->vc_common->prm_mod,
+			       vc->vc_common->smps_sa_reg);
+	vc_val &= ~vc->smps_sa_mask;
+	vc_val |= vdd->pmic_info->i2c_slave_addr << vc->smps_sa_shift;
+	vdd->write_reg(vc_val, vc->vc_common->prm_mod,
+		       vc->vc_common->smps_sa_reg);
+
+	/* Setup the VOLRA(pmic reg addr) in VC */
+	vc_val = vdd->read_reg(vc->vc_common->prm_mod,
+			       vc->vc_common->smps_volra_reg);
+	vc_val &= ~vc->smps_volra_mask;
+	vc_val |= vdd->pmic_info->pmic_reg << vc->smps_volra_shift;
+	vdd->write_reg(vc_val, vc->vc_common->prm_mod,
+		       vc->vc_common->smps_volra_reg);
+
+	/* Configure the setup times */
+	vc_val = vdd->read_reg(vc->vc_common->prm_mod, vdd->vfsm->voltsetup_reg);
+	vc_val &= ~vdd->vfsm->voltsetup_mask;
+	vc_val |= vdd->pmic_info->volt_setup_time <<
+			vdd->vfsm->voltsetup_shift;
+	vdd->write_reg(vc_val, vc->vc_common->prm_mod, vdd->vfsm->voltsetup_reg);
+
+	if (cpu_is_omap34xx())
+		omap3_vc_init_channel(voltdm);
+	else if (cpu_is_omap44xx())
+		omap4_vc_init_channel(voltdm);
+}
+

arch/arm/mach-omap2/vc.h

@@ -19,6 +19,8 @@
 
 #include <linux/kernel.h>
 
+struct voltagedomain;
+
 /**
  * struct omap_vc_common_data - per-VC register/bitfield data
  * @cmd_on_mask: ON bitmask in PRM_VC_CMD_VAL* register
@@ -81,5 +83,15 @@ extern struct omap_vc_instance_data omap4_vc_mpu_data;
 extern struct omap_vc_instance_data omap4_vc_iva_data;
 extern struct omap_vc_instance_data omap4_vc_core_data;
 
+void omap_vc_init_channel(struct voltagedomain *voltdm);
+int omap_vc_pre_scale(struct voltagedomain *voltdm,
+		      unsigned long target_volt,
+		      u8 *target_vsel, u8 *current_vsel);
+void omap_vc_post_scale(struct voltagedomain *voltdm,
+			unsigned long target_volt,
+			u8 target_vsel, u8 current_vsel);
+int omap_vc_bypass_scale_voltage(struct voltagedomain *voltdm,
+				 unsigned long target_volt);
+
 #endif