| /* |
| * Copyright (c) 2015, 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/export.h> |
| #include <linux/clk-provider.h> |
| #include <linux/regmap.h> |
| #include <linux/delay.h> |
| |
| #include "clk-alpha-pll.h" |
| |
| #define PLL_MODE 0x00 |
| # 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) |
| # define PLL_ACTIVE_FLAG BIT(30) |
| # define PLL_LOCK_DET BIT(31) |
| |
| #define PLL_L_VAL 0x04 |
| #define PLL_ALPHA_VAL 0x08 |
| #define PLL_ALPHA_VAL_U 0x0c |
| |
| #define PLL_USER_CTL 0x10 |
| # define PLL_POST_DIV_SHIFT 8 |
| # define PLL_POST_DIV_MASK 0xf |
| # define PLL_ALPHA_EN BIT(24) |
| # define PLL_VCO_SHIFT 20 |
| # define PLL_VCO_MASK 0x3 |
| |
| #define PLL_USER_CTL_U 0x14 |
| |
| #define PLL_CONFIG_CTL 0x18 |
| #define PLL_TEST_CTL 0x1c |
| #define PLL_TEST_CTL_U 0x20 |
| #define PLL_STATUS 0x24 |
| |
| /* |
| * Even though 40 bits are present, use only 32 for ease of calculation. |
| */ |
| #define ALPHA_REG_BITWIDTH 40 |
| #define ALPHA_BITWIDTH 32 |
| |
| #define to_clk_alpha_pll(_hw) container_of(to_clk_regmap(_hw), \ |
| struct clk_alpha_pll, clkr) |
| |
| #define to_clk_alpha_pll_postdiv(_hw) container_of(to_clk_regmap(_hw), \ |
| struct clk_alpha_pll_postdiv, clkr) |
| |
| static int wait_for_pll(struct clk_alpha_pll *pll) |
| { |
| u32 val, mask, off; |
| int count; |
| int ret; |
| const char *name = clk_hw_get_name(&pll->clkr.hw); |
| |
| off = pll->offset; |
| ret = regmap_read(pll->clkr.regmap, off + PLL_MODE, &val); |
| if (ret) |
| return ret; |
| |
| if (val & PLL_VOTE_FSM_ENA) |
| mask = PLL_ACTIVE_FLAG; |
| else |
| mask = PLL_LOCK_DET; |
| |
| /* Wait for pll to enable. */ |
| for (count = 100; count > 0; count--) { |
| ret = regmap_read(pll->clkr.regmap, off + PLL_MODE, &val); |
| if (ret) |
| return ret; |
| if ((val & mask) == mask) |
| return 0; |
| |
| udelay(1); |
| } |
| |
| WARN(1, "%s didn't enable after voting for it!\n", name); |
| return -ETIMEDOUT; |
| } |
| |
| static int clk_alpha_pll_enable(struct clk_hw *hw) |
| { |
| int ret; |
| struct clk_alpha_pll *pll = to_clk_alpha_pll(hw); |
| u32 val, mask, off; |
| |
| off = pll->offset; |
| |
| mask = PLL_OUTCTRL | PLL_RESET_N | PLL_BYPASSNL; |
| ret = regmap_read(pll->clkr.regmap, off + PLL_MODE, &val); |
| if (ret) |
| return ret; |
| |
| /* If in FSM mode, just vote for it */ |
| if (val & PLL_VOTE_FSM_ENA) { |
| ret = clk_enable_regmap(hw); |
| if (ret) |
| return ret; |
| return wait_for_pll(pll); |
| } |
| |
| /* Skip if already enabled */ |
| if ((val & mask) == mask) |
| return 0; |
| |
| ret = regmap_update_bits(pll->clkr.regmap, off + PLL_MODE, |
| PLL_BYPASSNL, PLL_BYPASSNL); |
| if (ret) |
| return ret; |
| |
| /* |
| * H/W requires a 5us delay between disabling the bypass and |
| * de-asserting the reset. |
| */ |
| mb(); |
| udelay(5); |
| |
| ret = regmap_update_bits(pll->clkr.regmap, off + PLL_MODE, |
| PLL_RESET_N, PLL_RESET_N); |
| if (ret) |
| return ret; |
| |
| ret = wait_for_pll(pll); |
| if (ret) |
| return ret; |
| |
| ret = regmap_update_bits(pll->clkr.regmap, off + PLL_MODE, |
| PLL_OUTCTRL, PLL_OUTCTRL); |
| |
| /* Ensure that the write above goes through before returning. */ |
| mb(); |
| return ret; |
| } |
| |
| static void clk_alpha_pll_disable(struct clk_hw *hw) |
| { |
| int ret; |
| struct clk_alpha_pll *pll = to_clk_alpha_pll(hw); |
| u32 val, mask, off; |
| |
| off = pll->offset; |
| |
| ret = regmap_read(pll->clkr.regmap, off + PLL_MODE, &val); |
| if (ret) |
| return; |
| |
| /* If in FSM mode, just unvote it */ |
| if (val & PLL_VOTE_FSM_ENA) { |
| clk_disable_regmap(hw); |
| return; |
| } |
| |
| mask = PLL_OUTCTRL; |
| regmap_update_bits(pll->clkr.regmap, off + PLL_MODE, mask, 0); |
| |
| /* Delay of 2 output clock ticks required until output is disabled */ |
| mb(); |
| udelay(1); |
| |
| mask = PLL_RESET_N | PLL_BYPASSNL; |
| regmap_update_bits(pll->clkr.regmap, off + PLL_MODE, mask, 0); |
| } |
| |
| static unsigned long alpha_pll_calc_rate(u64 prate, u32 l, u32 a) |
| { |
| return (prate * l) + ((prate * a) >> ALPHA_BITWIDTH); |
| } |
| |
| static unsigned long |
| alpha_pll_round_rate(unsigned long rate, unsigned long prate, u32 *l, u64 *a) |
| { |
| u64 remainder; |
| u64 quotient; |
| |
| quotient = rate; |
| remainder = do_div(quotient, prate); |
| *l = quotient; |
| |
| if (!remainder) { |
| *a = 0; |
| return rate; |
| } |
| |
| /* Upper ALPHA_BITWIDTH bits of Alpha */ |
| quotient = remainder << ALPHA_BITWIDTH; |
| remainder = do_div(quotient, prate); |
| |
| if (remainder) |
| quotient++; |
| |
| *a = quotient; |
| return alpha_pll_calc_rate(prate, *l, *a); |
| } |
| |
| static const struct pll_vco * |
| alpha_pll_find_vco(const struct clk_alpha_pll *pll, unsigned long rate) |
| { |
| const struct pll_vco *v = pll->vco_table; |
| const struct pll_vco *end = v + pll->num_vco; |
| |
| for (; v < end; v++) |
| if (rate >= v->min_freq && rate <= v->max_freq) |
| return v; |
| |
| return NULL; |
| } |
| |
| static unsigned long |
| clk_alpha_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) |
| { |
| u32 l, low, high, ctl; |
| u64 a = 0, prate = parent_rate; |
| struct clk_alpha_pll *pll = to_clk_alpha_pll(hw); |
| u32 off = pll->offset; |
| |
| regmap_read(pll->clkr.regmap, off + PLL_L_VAL, &l); |
| |
| regmap_read(pll->clkr.regmap, off + PLL_USER_CTL, &ctl); |
| if (ctl & PLL_ALPHA_EN) { |
| regmap_read(pll->clkr.regmap, off + PLL_ALPHA_VAL, &low); |
| regmap_read(pll->clkr.regmap, off + PLL_ALPHA_VAL_U, &high); |
| a = (u64)high << 32 | low; |
| a >>= ALPHA_REG_BITWIDTH - ALPHA_BITWIDTH; |
| } |
| |
| return alpha_pll_calc_rate(prate, l, a); |
| } |
| |
| static int clk_alpha_pll_set_rate(struct clk_hw *hw, unsigned long rate, |
| unsigned long prate) |
| { |
| struct clk_alpha_pll *pll = to_clk_alpha_pll(hw); |
| const struct pll_vco *vco; |
| u32 l, off = pll->offset; |
| u64 a; |
| |
| rate = alpha_pll_round_rate(rate, prate, &l, &a); |
| vco = alpha_pll_find_vco(pll, rate); |
| if (!vco) { |
| pr_err("alpha pll not in a valid vco range\n"); |
| return -EINVAL; |
| } |
| |
| a <<= (ALPHA_REG_BITWIDTH - ALPHA_BITWIDTH); |
| |
| regmap_write(pll->clkr.regmap, off + PLL_L_VAL, l); |
| regmap_write(pll->clkr.regmap, off + PLL_ALPHA_VAL, a); |
| regmap_write(pll->clkr.regmap, off + PLL_ALPHA_VAL_U, a >> 32); |
| |
| regmap_update_bits(pll->clkr.regmap, off + PLL_USER_CTL, |
| PLL_VCO_MASK << PLL_VCO_SHIFT, |
| vco->val << PLL_VCO_SHIFT); |
| |
| regmap_update_bits(pll->clkr.regmap, off + PLL_USER_CTL, PLL_ALPHA_EN, |
| PLL_ALPHA_EN); |
| |
| return 0; |
| } |
| |
| static long clk_alpha_pll_round_rate(struct clk_hw *hw, unsigned long rate, |
| unsigned long *prate) |
| { |
| struct clk_alpha_pll *pll = to_clk_alpha_pll(hw); |
| u32 l; |
| u64 a; |
| unsigned long min_freq, max_freq; |
| |
| rate = alpha_pll_round_rate(rate, *prate, &l, &a); |
| if (alpha_pll_find_vco(pll, rate)) |
| return rate; |
| |
| min_freq = pll->vco_table[0].min_freq; |
| max_freq = pll->vco_table[pll->num_vco - 1].max_freq; |
| |
| return clamp(rate, min_freq, max_freq); |
| } |
| |
| const struct clk_ops clk_alpha_pll_ops = { |
| .enable = clk_alpha_pll_enable, |
| .disable = clk_alpha_pll_disable, |
| .recalc_rate = clk_alpha_pll_recalc_rate, |
| .round_rate = clk_alpha_pll_round_rate, |
| .set_rate = clk_alpha_pll_set_rate, |
| }; |
| EXPORT_SYMBOL_GPL(clk_alpha_pll_ops); |
| |
| static unsigned long |
| clk_alpha_pll_postdiv_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) |
| { |
| struct clk_alpha_pll_postdiv *pll = to_clk_alpha_pll_postdiv(hw); |
| u32 ctl; |
| |
| regmap_read(pll->clkr.regmap, pll->offset + PLL_USER_CTL, &ctl); |
| |
| ctl >>= PLL_POST_DIV_SHIFT; |
| ctl &= PLL_POST_DIV_MASK; |
| |
| return parent_rate >> fls(ctl); |
| } |
| |
| static const struct clk_div_table clk_alpha_div_table[] = { |
| { 0x0, 1 }, |
| { 0x1, 2 }, |
| { 0x3, 4 }, |
| { 0x7, 8 }, |
| { 0xf, 16 }, |
| { } |
| }; |
| |
| static long |
| clk_alpha_pll_postdiv_round_rate(struct clk_hw *hw, unsigned long rate, |
| unsigned long *prate) |
| { |
| struct clk_alpha_pll_postdiv *pll = to_clk_alpha_pll_postdiv(hw); |
| |
| return divider_round_rate(hw, rate, prate, clk_alpha_div_table, |
| pll->width, CLK_DIVIDER_POWER_OF_TWO); |
| } |
| |
| static int clk_alpha_pll_postdiv_set_rate(struct clk_hw *hw, unsigned long rate, |
| unsigned long parent_rate) |
| { |
| struct clk_alpha_pll_postdiv *pll = to_clk_alpha_pll_postdiv(hw); |
| int div; |
| |
| /* 16 -> 0xf, 8 -> 0x7, 4 -> 0x3, 2 -> 0x1, 1 -> 0x0 */ |
| div = DIV_ROUND_UP_ULL((u64)parent_rate, rate) - 1; |
| |
| return regmap_update_bits(pll->clkr.regmap, pll->offset + PLL_USER_CTL, |
| PLL_POST_DIV_MASK << PLL_POST_DIV_SHIFT, |
| div << PLL_POST_DIV_SHIFT); |
| } |
| |
| const struct clk_ops clk_alpha_pll_postdiv_ops = { |
| .recalc_rate = clk_alpha_pll_postdiv_recalc_rate, |
| .round_rate = clk_alpha_pll_postdiv_round_rate, |
| .set_rate = clk_alpha_pll_postdiv_set_rate, |
| }; |
| EXPORT_SYMBOL_GPL(clk_alpha_pll_postdiv_ops); |