diff options
Diffstat (limited to 'drivers/clk/bcm/clk-iproc-pll.c')
-rw-r--r-- | drivers/clk/bcm/clk-iproc-pll.c | 716 |
1 files changed, 716 insertions, 0 deletions
diff --git a/drivers/clk/bcm/clk-iproc-pll.c b/drivers/clk/bcm/clk-iproc-pll.c new file mode 100644 index 0000000..46fb84b --- /dev/null +++ b/drivers/clk/bcm/clk-iproc-pll.c @@ -0,0 +1,716 @@ +/* + * Copyright (C) 2014 Broadcom Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; 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/err.h> +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/clkdev.h> +#include <linux/of_address.h> +#include <linux/delay.h> + +#include "clk-iproc.h" + +#define PLL_VCO_HIGH_SHIFT 19 +#define PLL_VCO_LOW_SHIFT 30 + +/* number of delay loops waiting for PLL to lock */ +#define LOCK_DELAY 100 + +/* number of VCO frequency bands */ +#define NUM_FREQ_BANDS 8 + +#define NUM_KP_BANDS 3 +enum kp_band { + KP_BAND_MID = 0, + KP_BAND_HIGH, + KP_BAND_HIGH_HIGH +}; + +static const unsigned int kp_table[NUM_KP_BANDS][NUM_FREQ_BANDS] = { + { 5, 6, 6, 7, 7, 8, 9, 10 }, + { 4, 4, 5, 5, 6, 7, 8, 9 }, + { 4, 5, 5, 6, 7, 8, 9, 10 }, +}; + +static const unsigned long ref_freq_table[NUM_FREQ_BANDS][2] = { + { 10000000, 12500000 }, + { 12500000, 15000000 }, + { 15000000, 20000000 }, + { 20000000, 25000000 }, + { 25000000, 50000000 }, + { 50000000, 75000000 }, + { 75000000, 100000000 }, + { 100000000, 125000000 }, +}; + +enum vco_freq_range { + VCO_LOW = 700000000U, + VCO_MID = 1200000000U, + VCO_HIGH = 2200000000U, + VCO_HIGH_HIGH = 3100000000U, + VCO_MAX = 4000000000U, +}; + +struct iproc_pll; + +struct iproc_clk { + struct clk_hw hw; + const char *name; + struct iproc_pll *pll; + unsigned long rate; + const struct iproc_clk_ctrl *ctrl; +}; + +struct iproc_pll { + void __iomem *pll_base; + void __iomem *pwr_base; + void __iomem *asiu_base; + + const struct iproc_pll_ctrl *ctrl; + const struct iproc_pll_vco_param *vco_param; + unsigned int num_vco_entries; + + struct clk_onecell_data clk_data; + struct iproc_clk *clks; +}; + +#define to_iproc_clk(hw) container_of(hw, struct iproc_clk, hw) + +/* + * Based on the target frequency, find a match from the VCO frequency parameter + * table and return its index + */ +static int pll_get_rate_index(struct iproc_pll *pll, unsigned int target_rate) +{ + int i; + + for (i = 0; i < pll->num_vco_entries; i++) + if (target_rate == pll->vco_param[i].rate) + break; + + if (i >= pll->num_vco_entries) + return -EINVAL; + + return i; +} + +static int get_kp(unsigned long ref_freq, enum kp_band kp_index) +{ + int i; + + if (ref_freq < ref_freq_table[0][0]) + return -EINVAL; + + for (i = 0; i < NUM_FREQ_BANDS; i++) { + if (ref_freq >= ref_freq_table[i][0] && + ref_freq < ref_freq_table[i][1]) + return kp_table[kp_index][i]; + } + return -EINVAL; +} + +static int pll_wait_for_lock(struct iproc_pll *pll) +{ + int i; + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + + for (i = 0; i < LOCK_DELAY; i++) { + u32 val = readl(pll->pll_base + ctrl->status.offset); + + if (val & (1 << ctrl->status.shift)) + return 0; + udelay(10); + } + + return -EIO; +} + +static void __pll_disable(struct iproc_pll *pll) +{ + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + u32 val; + + if (ctrl->flags & IPROC_CLK_PLL_ASIU) { + val = readl(pll->asiu_base + ctrl->asiu.offset); + val &= ~(1 << ctrl->asiu.en_shift); + writel(val, pll->asiu_base + ctrl->asiu.offset); + } + + /* latch input value so core power can be shut down */ + val = readl(pll->pwr_base + ctrl->aon.offset); + val |= (1 << ctrl->aon.iso_shift); + writel(val, pll->pwr_base + ctrl->aon.offset); + + /* power down the core */ + val &= ~(bit_mask(ctrl->aon.pwr_width) << ctrl->aon.pwr_shift); + writel(val, pll->pwr_base + ctrl->aon.offset); +} + +static int __pll_enable(struct iproc_pll *pll) +{ + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + u32 val; + + /* power up the PLL and make sure it's not latched */ + val = readl(pll->pwr_base + ctrl->aon.offset); + val |= bit_mask(ctrl->aon.pwr_width) << ctrl->aon.pwr_shift; + val &= ~(1 << ctrl->aon.iso_shift); + writel(val, pll->pwr_base + ctrl->aon.offset); + + /* certain PLLs also need to be ungated from the ASIU top level */ + if (ctrl->flags & IPROC_CLK_PLL_ASIU) { + val = readl(pll->asiu_base + ctrl->asiu.offset); + val |= (1 << ctrl->asiu.en_shift); + writel(val, pll->asiu_base + ctrl->asiu.offset); + } + + return 0; +} + +static void __pll_put_in_reset(struct iproc_pll *pll) +{ + u32 val; + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + const struct iproc_pll_reset_ctrl *reset = &ctrl->reset; + + val = readl(pll->pll_base + reset->offset); + val &= ~(1 << reset->reset_shift | 1 << reset->p_reset_shift); + writel(val, pll->pll_base + reset->offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + reset->offset); +} + +static void __pll_bring_out_reset(struct iproc_pll *pll, unsigned int kp, + unsigned int ka, unsigned int ki) +{ + u32 val; + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + const struct iproc_pll_reset_ctrl *reset = &ctrl->reset; + + val = readl(pll->pll_base + reset->offset); + val &= ~(bit_mask(reset->ki_width) << reset->ki_shift | + bit_mask(reset->kp_width) << reset->kp_shift | + bit_mask(reset->ka_width) << reset->ka_shift); + val |= ki << reset->ki_shift | kp << reset->kp_shift | + ka << reset->ka_shift; + val |= 1 << reset->reset_shift | 1 << reset->p_reset_shift; + writel(val, pll->pll_base + reset->offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + reset->offset); +} + +static int pll_set_rate(struct iproc_clk *clk, unsigned int rate_index, + unsigned long parent_rate) +{ + struct iproc_pll *pll = clk->pll; + const struct iproc_pll_vco_param *vco = &pll->vco_param[rate_index]; + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + int ka = 0, ki, kp, ret; + unsigned long rate = vco->rate; + u32 val; + enum kp_band kp_index; + unsigned long ref_freq; + + /* + * reference frequency = parent frequency / PDIV + * If PDIV = 0, then it becomes a multiplier (x2) + */ + if (vco->pdiv == 0) + ref_freq = parent_rate * 2; + else + ref_freq = parent_rate / vco->pdiv; + + /* determine Ki and Kp index based on target VCO frequency */ + if (rate >= VCO_LOW && rate < VCO_HIGH) { + ki = 4; + kp_index = KP_BAND_MID; + } else if (rate >= VCO_HIGH && rate && rate < VCO_HIGH_HIGH) { + ki = 3; + kp_index = KP_BAND_HIGH; + } else if (rate >= VCO_HIGH_HIGH && rate < VCO_MAX) { + ki = 3; + kp_index = KP_BAND_HIGH_HIGH; + } else { + pr_err("%s: pll: %s has invalid rate: %lu\n", __func__, + clk->name, rate); + return -EINVAL; + } + + kp = get_kp(ref_freq, kp_index); + if (kp < 0) { + pr_err("%s: pll: %s has invalid kp\n", __func__, clk->name); + return kp; + } + + ret = __pll_enable(pll); + if (ret) { + pr_err("%s: pll: %s fails to enable\n", __func__, clk->name); + return ret; + } + + /* put PLL in reset */ + __pll_put_in_reset(pll); + + writel(0, pll->pll_base + ctrl->vco_ctrl.u_offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->vco_ctrl.u_offset); + val = readl(pll->pll_base + ctrl->vco_ctrl.l_offset); + + if (rate >= VCO_LOW && rate < VCO_MID) + val |= (1 << PLL_VCO_LOW_SHIFT); + + if (rate < VCO_HIGH) + val &= ~(1 << PLL_VCO_HIGH_SHIFT); + else + val |= (1 << PLL_VCO_HIGH_SHIFT); + + writel(val, pll->pll_base + ctrl->vco_ctrl.l_offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->vco_ctrl.l_offset); + + /* program integer part of NDIV */ + val = readl(pll->pll_base + ctrl->ndiv_int.offset); + val &= ~(bit_mask(ctrl->ndiv_int.width) << ctrl->ndiv_int.shift); + val |= vco->ndiv_int << ctrl->ndiv_int.shift; + writel(val, pll->pll_base + ctrl->ndiv_int.offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->ndiv_int.offset); + + /* program fractional part of NDIV */ + if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) { + val = readl(pll->pll_base + ctrl->ndiv_frac.offset); + val &= ~(bit_mask(ctrl->ndiv_frac.width) << + ctrl->ndiv_frac.shift); + val |= vco->ndiv_frac << ctrl->ndiv_frac.shift; + writel(val, pll->pll_base + ctrl->ndiv_frac.offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->ndiv_frac.offset); + } + + /* program PDIV */ + val = readl(pll->pll_base + ctrl->pdiv.offset); + val &= ~(bit_mask(ctrl->pdiv.width) << ctrl->pdiv.shift); + val |= vco->pdiv << ctrl->pdiv.shift; + writel(val, pll->pll_base + ctrl->pdiv.offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->pdiv.offset); + + __pll_bring_out_reset(pll, kp, ka, ki); + + ret = pll_wait_for_lock(pll); + if (ret < 0) { + pr_err("%s: pll: %s failed to lock\n", __func__, clk->name); + return ret; + } + + return 0; +} + +static int iproc_pll_enable(struct clk_hw *hw) +{ + struct iproc_clk *clk = to_iproc_clk(hw); + struct iproc_pll *pll = clk->pll; + + return __pll_enable(pll); +} + +static void iproc_pll_disable(struct clk_hw *hw) +{ + struct iproc_clk *clk = to_iproc_clk(hw); + struct iproc_pll *pll = clk->pll; + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + + if (ctrl->flags & IPROC_CLK_AON) + return; + + __pll_disable(pll); +} + +static unsigned long iproc_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct iproc_clk *clk = to_iproc_clk(hw); + struct iproc_pll *pll = clk->pll; + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + u32 val; + u64 ndiv; + unsigned int ndiv_int, ndiv_frac, pdiv; + + if (parent_rate == 0) + return 0; + + /* PLL needs to be locked */ + val = readl(pll->pll_base + ctrl->status.offset); + if ((val & (1 << ctrl->status.shift)) == 0) { + clk->rate = 0; + return 0; + } + + /* + * PLL output frequency = + * + * ((ndiv_int + ndiv_frac / 2^20) * (parent clock rate / pdiv) + */ + val = readl(pll->pll_base + ctrl->ndiv_int.offset); + ndiv_int = (val >> ctrl->ndiv_int.shift) & + bit_mask(ctrl->ndiv_int.width); + ndiv = ndiv_int << ctrl->ndiv_int.shift; + + if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) { + val = readl(pll->pll_base + ctrl->ndiv_frac.offset); + ndiv_frac = (val >> ctrl->ndiv_frac.shift) & + bit_mask(ctrl->ndiv_frac.width); + + if (ndiv_frac != 0) + ndiv = (ndiv_int << ctrl->ndiv_int.shift) | ndiv_frac; + } + + val = readl(pll->pll_base + ctrl->pdiv.offset); + pdiv = (val >> ctrl->pdiv.shift) & bit_mask(ctrl->pdiv.width); + + clk->rate = (ndiv * parent_rate) >> ctrl->ndiv_int.shift; + + if (pdiv == 0) + clk->rate *= 2; + else + clk->rate /= pdiv; + + return clk->rate; +} + +static long iproc_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned i; + struct iproc_clk *clk = to_iproc_clk(hw); + struct iproc_pll *pll = clk->pll; + + if (rate == 0 || *parent_rate == 0 || !pll->vco_param) + return -EINVAL; + + for (i = 0; i < pll->num_vco_entries; i++) { + if (rate <= pll->vco_param[i].rate) + break; + } + + if (i == pll->num_vco_entries) + i--; + + return pll->vco_param[i].rate; +} + +static int iproc_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct iproc_clk *clk = to_iproc_clk(hw); + struct iproc_pll *pll = clk->pll; + int rate_index, ret; + + rate_index = pll_get_rate_index(pll, rate); + if (rate_index < 0) + return rate_index; + + ret = pll_set_rate(clk, rate_index, parent_rate); + return ret; +} + +static const struct clk_ops iproc_pll_ops = { + .enable = iproc_pll_enable, + .disable = iproc_pll_disable, + .recalc_rate = iproc_pll_recalc_rate, + .round_rate = iproc_pll_round_rate, + .set_rate = iproc_pll_set_rate, +}; + +static int iproc_clk_enable(struct clk_hw *hw) +{ + struct iproc_clk *clk = to_iproc_clk(hw); + const struct iproc_clk_ctrl *ctrl = clk->ctrl; + struct iproc_pll *pll = clk->pll; + u32 val; + + /* channel enable is active low */ + val = readl(pll->pll_base + ctrl->enable.offset); + val &= ~(1 << ctrl->enable.enable_shift); + writel(val, pll->pll_base + ctrl->enable.offset); + + /* also make sure channel is not held */ + val = readl(pll->pll_base + ctrl->enable.offset); + val &= ~(1 << ctrl->enable.hold_shift); + writel(val, pll->pll_base + ctrl->enable.offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->enable.offset); + + return 0; +} + +static void iproc_clk_disable(struct clk_hw *hw) +{ + struct iproc_clk *clk = to_iproc_clk(hw); + const struct iproc_clk_ctrl *ctrl = clk->ctrl; + struct iproc_pll *pll = clk->pll; + u32 val; + + if (ctrl->flags & IPROC_CLK_AON) + return; + + val = readl(pll->pll_base + ctrl->enable.offset); + val |= 1 << ctrl->enable.enable_shift; + writel(val, pll->pll_base + ctrl->enable.offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->enable.offset); +} + +static unsigned long iproc_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct iproc_clk *clk = to_iproc_clk(hw); + const struct iproc_clk_ctrl *ctrl = clk->ctrl; + struct iproc_pll *pll = clk->pll; + u32 val; + unsigned int mdiv; + + if (parent_rate == 0) + return 0; + + val = readl(pll->pll_base + ctrl->mdiv.offset); + mdiv = (val >> ctrl->mdiv.shift) & bit_mask(ctrl->mdiv.width); + if (mdiv == 0) + mdiv = 256; + + clk->rate = parent_rate / mdiv; + + return clk->rate; +} + +static long iproc_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned int div; + + if (rate == 0 || *parent_rate == 0) + return -EINVAL; + + if (rate == *parent_rate) + return *parent_rate; + + div = DIV_ROUND_UP(*parent_rate, rate); + if (div < 2) + return *parent_rate; + + if (div > 256) + div = 256; + + return *parent_rate / div; +} + +static int iproc_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct iproc_clk *clk = to_iproc_clk(hw); + const struct iproc_clk_ctrl *ctrl = clk->ctrl; + struct iproc_pll *pll = clk->pll; + u32 val; + unsigned int div; + + if (rate == 0 || parent_rate == 0) + return -EINVAL; + + div = DIV_ROUND_UP(parent_rate, rate); + if (div > 256) + return -EINVAL; + + val = readl(pll->pll_base + ctrl->mdiv.offset); + if (div == 256) { + val &= ~(bit_mask(ctrl->mdiv.width) << ctrl->mdiv.shift); + } else { + val &= ~(bit_mask(ctrl->mdiv.width) << ctrl->mdiv.shift); + val |= div << ctrl->mdiv.shift; + } + writel(val, pll->pll_base + ctrl->mdiv.offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->mdiv.offset); + clk->rate = parent_rate / div; + + return 0; +} + +static const struct clk_ops iproc_clk_ops = { + .enable = iproc_clk_enable, + .disable = iproc_clk_disable, + .recalc_rate = iproc_clk_recalc_rate, + .round_rate = iproc_clk_round_rate, + .set_rate = iproc_clk_set_rate, +}; + +/** + * Some PLLs require the PLL SW override bit to be set before changes can be + * applied to the PLL + */ +static void iproc_pll_sw_cfg(struct iproc_pll *pll) +{ + const struct iproc_pll_ctrl *ctrl = pll->ctrl; + + if (ctrl->flags & IPROC_CLK_PLL_NEEDS_SW_CFG) { + u32 val; + + val = readl(pll->pll_base + ctrl->sw_ctrl.offset); + val |= BIT(ctrl->sw_ctrl.shift); + writel(val, pll->pll_base + ctrl->sw_ctrl.offset); + if (unlikely(ctrl->flags & IPROC_CLK_NEEDS_READ_BACK)) + readl(pll->pll_base + ctrl->sw_ctrl.offset); + } +} + +void __init iproc_pll_clk_setup(struct device_node *node, + const struct iproc_pll_ctrl *pll_ctrl, + const struct iproc_pll_vco_param *vco, + unsigned int num_vco_entries, + const struct iproc_clk_ctrl *clk_ctrl, + unsigned int num_clks) +{ + int i, ret; + struct clk *clk; + struct iproc_pll *pll; + struct iproc_clk *iclk; + struct clk_init_data init; + const char *parent_name; + + if (WARN_ON(!pll_ctrl) || WARN_ON(!clk_ctrl)) + return; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (WARN_ON(!pll)) + return; + + pll->clk_data.clk_num = num_clks; + pll->clk_data.clks = kcalloc(num_clks, sizeof(*pll->clk_data.clks), + GFP_KERNEL); + if (WARN_ON(!pll->clk_data.clks)) + goto err_clk_data; + + pll->clks = kcalloc(num_clks, sizeof(*pll->clks), GFP_KERNEL); + if (WARN_ON(!pll->clks)) + goto err_clks; + + pll->pll_base = of_iomap(node, 0); + if (WARN_ON(!pll->pll_base)) + goto err_pll_iomap; + + pll->pwr_base = of_iomap(node, 1); + if (WARN_ON(!pll->pwr_base)) + goto err_pwr_iomap; + + /* some PLLs require gating control at the top ASIU level */ + if (pll_ctrl->flags & IPROC_CLK_PLL_ASIU) { + pll->asiu_base = of_iomap(node, 2); + if (WARN_ON(!pll->asiu_base)) + goto err_asiu_iomap; + } + + /* initialize and register the PLL itself */ + pll->ctrl = pll_ctrl; + + iclk = &pll->clks[0]; + iclk->pll = pll; + iclk->name = node->name; + + init.name = node->name; + init.ops = &iproc_pll_ops; + init.flags = 0; + parent_name = of_clk_get_parent_name(node, 0); + init.parent_names = (parent_name ? &parent_name : NULL); + init.num_parents = (parent_name ? 1 : 0); + iclk->hw.init = &init; + + if (vco) { + pll->num_vco_entries = num_vco_entries; + pll->vco_param = vco; + } + + iproc_pll_sw_cfg(pll); + + clk = clk_register(NULL, &iclk->hw); + if (WARN_ON(IS_ERR(clk))) + goto err_pll_register; + + pll->clk_data.clks[0] = clk; + + /* now initialize and register all leaf clocks */ + for (i = 1; i < num_clks; i++) { + const char *clk_name; + + memset(&init, 0, sizeof(init)); + parent_name = node->name; + + clk_name = kzalloc(IPROC_CLK_NAME_LEN, GFP_KERNEL); + if (WARN_ON(!clk_name)) + goto err_clk_register; + + ret = of_property_read_string_index(node, "clock-output-names", + i, &clk_name); + if (WARN_ON(ret)) + goto err_clk_register; + + iclk = &pll->clks[i]; + iclk->name = clk_name; + iclk->pll = pll; + iclk->ctrl = &clk_ctrl[i]; + + init.name = clk_name; + init.ops = &iproc_clk_ops; + init.flags = 0; + init.parent_names = (parent_name ? &parent_name : NULL); + init.num_parents = (parent_name ? 1 : 0); + iclk->hw.init = &init; + + clk = clk_register(NULL, &iclk->hw); + if (WARN_ON(IS_ERR(clk))) + goto err_clk_register; + + pll->clk_data.clks[i] = clk; + } + + ret = of_clk_add_provider(node, of_clk_src_onecell_get, &pll->clk_data); + if (WARN_ON(ret)) + goto err_clk_register; + + return; + +err_clk_register: + for (i = 0; i < num_clks; i++) { + kfree(pll->clks[i].name); + clk_unregister(pll->clk_data.clks[i]); + } + +err_pll_register: + if (pll->asiu_base) + iounmap(pll->asiu_base); + +err_asiu_iomap: + iounmap(pll->pwr_base); + +err_pwr_iomap: + iounmap(pll->pll_base); + +err_pll_iomap: + kfree(pll->clks); + +err_clks: + kfree(pll->clk_data.clks); + +err_clk_data: + kfree(pll); +} |