diff options
Diffstat (limited to 'drivers/clk/qcom/clk-pll.c')
| -rw-r--r-- | drivers/clk/qcom/clk-pll.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-pll.c b/drivers/clk/qcom/clk-pll.c new file mode 100644 index 000000000000..0f927c538613 --- /dev/null +++ b/drivers/clk/qcom/clk-pll.c @@ -0,0 +1,222 @@ +/* + * Copyright (c) 2013, The Linux Foundation. All rights reserved. + * + * 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/kernel.h> +#include <linux/bitops.h> +#include <linux/err.h> +#include <linux/bug.h> +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/clk-provider.h> +#include <linux/regmap.h> + +#include <asm/div64.h> + +#include "clk-pll.h" + +#define PLL_OUTCTRL BIT(0) +#define PLL_BYPASSNL BIT(1) +#define PLL_RESET_N BIT(2) +#define PLL_LOCK_COUNT_SHIFT 8 +#define PLL_LOCK_COUNT_MASK 0x3f +#define PLL_BIAS_COUNT_SHIFT 14 +#define PLL_BIAS_COUNT_MASK 0x3f +#define PLL_VOTE_FSM_ENA BIT(20) +#define PLL_VOTE_FSM_RESET BIT(21) + +static int clk_pll_enable(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + int ret; + u32 mask, val; + + mask = PLL_OUTCTRL | PLL_RESET_N | PLL_BYPASSNL; + ret = regmap_read(pll->clkr.regmap, pll->mode_reg, &val); + if (ret) + return ret; + + /* Skip if already enabled or in FSM mode */ + if ((val & mask) == mask || val & PLL_VOTE_FSM_ENA) + return 0; + + /* Disable PLL bypass mode. */ + ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_BYPASSNL, + PLL_BYPASSNL); + if (ret) + return ret; + + /* + * H/W requires a 5us delay between disabling the bypass and + * de-asserting the reset. Delay 10us just to be safe. + */ + udelay(10); + + /* De-assert active-low PLL reset. */ + ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_RESET_N, + PLL_RESET_N); + if (ret) + return ret; + + /* Wait until PLL is locked. */ + udelay(50); + + /* Enable PLL output. */ + ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_OUTCTRL, + PLL_OUTCTRL); + if (ret) + return ret; + + return 0; +} + +static void clk_pll_disable(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + u32 mask; + u32 val; + + regmap_read(pll->clkr.regmap, pll->mode_reg, &val); + /* Skip if in FSM mode */ + if (val & PLL_VOTE_FSM_ENA) + return; + mask = PLL_OUTCTRL | PLL_RESET_N | PLL_BYPASSNL; + regmap_update_bits(pll->clkr.regmap, pll->mode_reg, mask, 0); +} + +static unsigned long +clk_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) +{ + struct clk_pll *pll = to_clk_pll(hw); + u32 l, m, n; + unsigned long rate; + u64 tmp; + + regmap_read(pll->clkr.regmap, pll->l_reg, &l); + regmap_read(pll->clkr.regmap, pll->m_reg, &m); + regmap_read(pll->clkr.regmap, pll->n_reg, &n); + + l &= 0x3ff; + m &= 0x7ffff; + n &= 0x7ffff; + + rate = parent_rate * l; + if (n) { + tmp = parent_rate; + tmp *= m; + do_div(tmp, n); + rate += tmp; + } + return rate; +} + +const struct clk_ops clk_pll_ops = { + .enable = clk_pll_enable, + .disable = clk_pll_disable, + .recalc_rate = clk_pll_recalc_rate, +}; +EXPORT_SYMBOL_GPL(clk_pll_ops); + +static int wait_for_pll(struct clk_pll *pll) +{ + u32 val; + int count; + int ret; + const char *name = __clk_get_name(pll->clkr.hw.clk); + + /* Wait for pll to enable. */ + for (count = 200; count > 0; count--) { + ret = regmap_read(pll->clkr.regmap, pll->status_reg, &val); + if (ret) + return ret; + if (val & BIT(pll->status_bit)) + return 0; + udelay(1); + } + + WARN(1, "%s didn't enable after voting for it!\n", name); + return -ETIMEDOUT; +} + +static int clk_pll_vote_enable(struct clk_hw *hw) +{ + int ret; + struct clk_pll *p = to_clk_pll(__clk_get_hw(__clk_get_parent(hw->clk))); + + ret = clk_enable_regmap(hw); + if (ret) + return ret; + + return wait_for_pll(p); +} + +const struct clk_ops clk_pll_vote_ops = { + .enable = clk_pll_vote_enable, + .disable = clk_disable_regmap, +}; +EXPORT_SYMBOL_GPL(clk_pll_vote_ops); + +static void +clk_pll_set_fsm_mode(struct clk_pll *pll, struct regmap *regmap) +{ + u32 val; + u32 mask; + + /* De-assert reset to FSM */ + regmap_update_bits(regmap, pll->mode_reg, PLL_VOTE_FSM_RESET, 0); + + /* Program bias count and lock count */ + val = 1 << PLL_BIAS_COUNT_SHIFT; + mask = PLL_BIAS_COUNT_MASK << PLL_BIAS_COUNT_SHIFT; + mask |= PLL_LOCK_COUNT_MASK << PLL_LOCK_COUNT_SHIFT; + regmap_update_bits(regmap, pll->mode_reg, mask, val); + + /* Enable PLL FSM voting */ + regmap_update_bits(regmap, pll->mode_reg, PLL_VOTE_FSM_ENA, + PLL_VOTE_FSM_ENA); +} + +static void clk_pll_configure(struct clk_pll *pll, struct regmap *regmap, + const struct pll_config *config) +{ + u32 val; + u32 mask; + + regmap_write(regmap, pll->l_reg, config->l); + regmap_write(regmap, pll->m_reg, config->m); + regmap_write(regmap, pll->n_reg, config->n); + + val = config->vco_val; + val |= config->pre_div_val; + val |= config->post_div_val; + val |= config->mn_ena_mask; + val |= config->main_output_mask; + val |= config->aux_output_mask; + + mask = config->vco_mask; + mask |= config->pre_div_mask; + mask |= config->post_div_mask; + mask |= config->mn_ena_mask; + mask |= config->main_output_mask; + mask |= config->aux_output_mask; + + regmap_update_bits(regmap, pll->config_reg, mask, val); +} + +void clk_pll_configure_sr_hpm_lp(struct clk_pll *pll, struct regmap *regmap, + const struct pll_config *config, bool fsm_mode) +{ + clk_pll_configure(pll, regmap, config); + if (fsm_mode) + clk_pll_set_fsm_mode(pll, regmap); +} +EXPORT_SYMBOL_GPL(clk_pll_configure_sr_hpm_lp); |