| /* |
| * 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" |
| |
| /** |
| * struct omap_vc_channel_cfg - describe the cfg_channel bitfield |
| * @sa: bit for slave address |
| * @rav: bit for voltage configuration register |
| * @rac: bit for command configuration register |
| * @racen: enable bit for RAC |
| * @cmd: bit for command value set selection |
| * |
| * Channel configuration bits, common for OMAP3+ |
| * OMAP3 register: PRM_VC_CH_CONF |
| * OMAP4 register: PRM_VC_CFG_CHANNEL |
| * OMAP5 register: PRM_VC_SMPS_<voltdm>_CONFIG |
| */ |
| struct omap_vc_channel_cfg { |
| u8 sa; |
| u8 rav; |
| u8 rac; |
| u8 racen; |
| u8 cmd; |
| }; |
| |
| static struct omap_vc_channel_cfg vc_default_channel_cfg = { |
| .sa = BIT(0), |
| .rav = BIT(1), |
| .rac = BIT(2), |
| .racen = BIT(3), |
| .cmd = BIT(4), |
| }; |
| |
| /* |
| * On OMAP3+, all VC channels have the above default bitfield |
| * configuration, except the OMAP4 MPU channel. This appears |
| * to be a freak accident as every other VC channel has the |
| * default configuration, thus creating a mutant channel config. |
| */ |
| static struct omap_vc_channel_cfg vc_mutant_channel_cfg = { |
| .sa = BIT(0), |
| .rav = BIT(2), |
| .rac = BIT(3), |
| .racen = BIT(4), |
| .cmd = BIT(1), |
| }; |
| |
| static struct omap_vc_channel_cfg *vc_cfg_bits; |
| #define CFG_CHANNEL_MASK 0x1f |
| |
| /** |
| * omap_vc_config_channel - configure VC channel to PMIC mappings |
| * @voltdm: pointer to voltagdomain defining the desired VC channel |
| * |
| * Configures the VC channel to PMIC mappings for the following |
| * PMIC settings |
| * - i2c slave address (SA) |
| * - voltage configuration address (RAV) |
| * - command configuration address (RAC) and enable bit (RACEN) |
| * - command values for ON, ONLP, RET and OFF (CMD) |
| * |
| * This function currently only allows flexible configuration of the |
| * non-default channel. Starting with OMAP4, there are more than 2 |
| * channels, with one defined as the default (on OMAP4, it's MPU.) |
| * Only the non-default channel can be configured. |
| */ |
| static int omap_vc_config_channel(struct voltagedomain *voltdm) |
| { |
| struct omap_vc_channel *vc = voltdm->vc; |
| |
| /* |
| * For default channel, the only configurable bit is RACEN. |
| * All others must stay at zero (see function comment above.) |
| */ |
| if (vc->flags & OMAP_VC_CHANNEL_DEFAULT) |
| vc->cfg_channel &= vc_cfg_bits->racen; |
| |
| voltdm->rmw(CFG_CHANNEL_MASK << vc->cfg_channel_sa_shift, |
| vc->cfg_channel << vc->cfg_channel_sa_shift, |
| vc->cfg_channel_reg); |
| |
| return 0; |
| } |
| |
| /* 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_channel *vc = voltdm->vc; |
| u32 vc_cmdval; |
| |
| /* Check if sufficient pmic info is available for this vdd */ |
| if (!voltdm->pmic) { |
| pr_err("%s: Insufficient pmic info to scale the vdd_%s\n", |
| __func__, voltdm->name); |
| return -EINVAL; |
| } |
| |
| if (!voltdm->pmic->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 (!voltdm->read || !voltdm->write) { |
| pr_err("%s: No read/write API for accessing vdd_%s regs\n", |
| __func__, voltdm->name); |
| return -EINVAL; |
| } |
| |
| *target_vsel = voltdm->pmic->uv_to_vsel(target_volt); |
| *current_vsel = voltdm->pmic->uv_to_vsel(voltdm->nominal_volt); |
| |
| /* Setting the ON voltage to the new target voltage */ |
| vc_cmdval = voltdm->read(vc->cmdval_reg); |
| vc_cmdval &= ~vc->common->cmd_on_mask; |
| vc_cmdval |= (*target_vsel << vc->common->cmd_on_shift); |
| voltdm->write(vc_cmdval, vc->cmdval_reg); |
| |
| omap_vp_update_errorgain(voltdm, target_volt); |
| |
| return 0; |
| } |
| |
| void omap_vc_post_scale(struct voltagedomain *voltdm, |
| unsigned long target_volt, |
| u8 target_vsel, u8 current_vsel) |
| { |
| 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 * voltdm->pmic->step_size) / |
| voltdm->pmic->slew_rate) + 2; |
| udelay(smps_delay); |
| } |
| |
| /* vc_bypass_scale - VC bypass method of voltage scaling */ |
| int omap_vc_bypass_scale(struct voltagedomain *voltdm, |
| unsigned long target_volt) |
| { |
| struct omap_vc_channel *vc = voltdm->vc; |
| 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, ¤t_vsel); |
| if (ret) |
| return ret; |
| |
| vc_valid = vc->common->valid; |
| vc_bypass_val_reg = vc->common->bypass_val_reg; |
| vc_bypass_value = (target_vsel << vc->common->data_shift) | |
| (vc->volt_reg_addr << vc->common->regaddr_shift) | |
| (vc->i2c_slave_addr << vc->common->slaveaddr_shift); |
| |
| voltdm->write(vc_bypass_value, vc_bypass_val_reg); |
| voltdm->write(vc_bypass_value | vc_valid, vc_bypass_val_reg); |
| |
| vc_bypass_value = voltdm->read(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 = voltdm->read(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) |
| { |
| /* |
| * Voltage Manager FSM parameters init |
| * XXX This data should be passed in from the board file |
| */ |
| voltdm->write(OMAP3_CLKSETUP, OMAP3_PRM_CLKSETUP_OFFSET); |
| voltdm->write(OMAP3_VOLTOFFSET, OMAP3_PRM_VOLTOFFSET_OFFSET); |
| voltdm->write(OMAP3_VOLTSETUP2, OMAP3_PRM_VOLTSETUP2_OFFSET); |
| } |
| |
| static void __init omap3_vc_init_channel(struct voltagedomain *voltdm) |
| { |
| static bool is_initialized; |
| |
| if (is_initialized) |
| return; |
| |
| omap3_vfsm_init(voltdm); |
| |
| is_initialized = true; |
| } |
| |
| |
| /* OMAP4 specific voltage init functions */ |
| static void __init omap4_vc_init_channel(struct voltagedomain *voltdm) |
| { |
| static bool is_initialized; |
| u32 vc_val; |
| |
| if (is_initialized) |
| return; |
| |
| /* XXX These are magic numbers and do not belong! */ |
| vc_val = (0x60 << OMAP4430_SCLL_SHIFT | 0x26 << OMAP4430_SCLH_SHIFT); |
| voltdm->write(vc_val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET); |
| |
| is_initialized = true; |
| } |
| |
| /** |
| * omap_vc_i2c_init - initialize I2C interface to PMIC |
| * @voltdm: voltage domain containing VC data |
| * |
| * Use PMIC supplied seetings for I2C high-speed mode and |
| * master code (if set) and program the VC I2C configuration |
| * register. |
| * |
| * The VC I2C configuration is common to all VC channels, |
| * so this function only configures I2C for the first VC |
| * channel registers. All other VC channels will use the |
| * same configuration. |
| */ |
| static void __init omap_vc_i2c_init(struct voltagedomain *voltdm) |
| { |
| struct omap_vc_channel *vc = voltdm->vc; |
| static bool initialized; |
| static bool i2c_high_speed; |
| u8 mcode; |
| |
| if (initialized) { |
| if (voltdm->pmic->i2c_high_speed != i2c_high_speed) |
| pr_warn("%s: I2C config for all channels must match.", |
| __func__); |
| return; |
| } |
| |
| i2c_high_speed = voltdm->pmic->i2c_high_speed; |
| if (i2c_high_speed) |
| voltdm->rmw(vc->common->i2c_cfg_hsen_mask, |
| vc->common->i2c_cfg_hsen_mask, |
| vc->common->i2c_cfg_reg); |
| |
| mcode = voltdm->pmic->i2c_mcode; |
| if (mcode) |
| voltdm->rmw(vc->common->i2c_mcode_mask, |
| mcode << __ffs(vc->common->i2c_mcode_mask), |
| vc->common->i2c_cfg_reg); |
| |
| initialized = true; |
| } |
| |
| void __init omap_vc_init_channel(struct voltagedomain *voltdm) |
| { |
| struct omap_vc_channel *vc = voltdm->vc; |
| u8 on_vsel, onlp_vsel, ret_vsel, off_vsel; |
| u32 val; |
| |
| if (!voltdm->pmic || !voltdm->pmic->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 (!voltdm->read || !voltdm->write) { |
| pr_err("%s: No read/write API for accessing vdd_%s regs\n", |
| __func__, voltdm->name); |
| return; |
| } |
| |
| vc->cfg_channel = 0; |
| if (vc->flags & OMAP_VC_CHANNEL_CFG_MUTANT) |
| vc_cfg_bits = &vc_mutant_channel_cfg; |
| else |
| vc_cfg_bits = &vc_default_channel_cfg; |
| |
| /* get PMIC/board specific settings */ |
| vc->i2c_slave_addr = voltdm->pmic->i2c_slave_addr; |
| vc->volt_reg_addr = voltdm->pmic->volt_reg_addr; |
| vc->cmd_reg_addr = voltdm->pmic->cmd_reg_addr; |
| vc->setup_time = voltdm->pmic->volt_setup_time; |
| |
| /* Configure the i2c slave address for this VC */ |
| voltdm->rmw(vc->smps_sa_mask, |
| vc->i2c_slave_addr << __ffs(vc->smps_sa_mask), |
| vc->smps_sa_reg); |
| vc->cfg_channel |= vc_cfg_bits->sa; |
| |
| /* |
| * Configure the PMIC register addresses. |
| */ |
| voltdm->rmw(vc->smps_volra_mask, |
| vc->volt_reg_addr << __ffs(vc->smps_volra_mask), |
| vc->smps_volra_reg); |
| vc->cfg_channel |= vc_cfg_bits->rav; |
| |
| if (vc->cmd_reg_addr) { |
| voltdm->rmw(vc->smps_cmdra_mask, |
| vc->cmd_reg_addr << __ffs(vc->smps_cmdra_mask), |
| vc->smps_cmdra_reg); |
| vc->cfg_channel |= vc_cfg_bits->rac | vc_cfg_bits->racen; |
| } |
| |
| /* Set up the on, inactive, retention and off voltage */ |
| on_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->on_volt); |
| onlp_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->onlp_volt); |
| ret_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->ret_volt); |
| off_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->off_volt); |
| val = ((on_vsel << vc->common->cmd_on_shift) | |
| (onlp_vsel << vc->common->cmd_onlp_shift) | |
| (ret_vsel << vc->common->cmd_ret_shift) | |
| (off_vsel << vc->common->cmd_off_shift)); |
| voltdm->write(val, vc->cmdval_reg); |
| vc->cfg_channel |= vc_cfg_bits->cmd; |
| |
| /* Channel configuration */ |
| omap_vc_config_channel(voltdm); |
| |
| /* Configure the setup times */ |
| voltdm->rmw(voltdm->vfsm->voltsetup_mask, |
| vc->setup_time << __ffs(voltdm->vfsm->voltsetup_mask), |
| voltdm->vfsm->voltsetup_reg); |
| |
| omap_vc_i2c_init(voltdm); |
| |
| if (cpu_is_omap34xx()) |
| omap3_vc_init_channel(voltdm); |
| else if (cpu_is_omap44xx()) |
| omap4_vc_init_channel(voltdm); |
| } |
| |