diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-26 12:42:29 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-26 12:42:29 -0700 |
commit | 27953437059c64d14086196eb96f43c78caa9db3 (patch) | |
tree | 0cfd5fb21262a6db3de0c64462847b4c0c43e9df /drivers/clk/spear/clk-vco-pll.c | |
parent | 2c757fd5d1a92086f225a75a8fac7cab242d11b0 (diff) | |
parent | 3c0dec5f58b3c7b3627715126d1bf9b030a076f0 (diff) |
Merge tag 'clock' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull arm-soc clock driver changes from Olof Johansson:
"The new clock subsystem was merged in linux-3.4 without any users,
this now moves the first three platforms over to it: imx, mxs and
spear.
The series also contains the changes for the clock subsystem itself,
since Mike preferred to have it together with the platforms that
require these changes, in order to avoid interdependencies and
conflicts."
Fix up trivial conflicts in arch/arm/mach-kirkwood/common.c (code
removed in one branch, added OF support in another) and
drivers/dma/imx-sdma.c (independent changes next to each other).
* tag 'clock' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (97 commits)
clk: Fix CLK_SET_RATE_GATE flag validation in clk_set_rate().
clk: Provide dummy clk_unregister()
SPEAr: Update defconfigs
SPEAr: Add SMI NOR partition info in dts files
SPEAr: Switch to common clock framework
SPEAr: Call clk_prepare() before calling clk_enable
SPEAr: clk: Add General Purpose Timer Synthesizer clock
SPEAr: clk: Add Fractional Synthesizer clock
SPEAr: clk: Add Auxiliary Synthesizer clock
SPEAr: clk: Add VCO-PLL Synthesizer clock
SPEAr: Add DT bindings for SPEAr's timer
ARM i.MX: remove now unused clock files
ARM: i.MX6: implement clocks using common clock framework
ARM i.MX35: implement clocks using common clock framework
ARM i.MX5: implement clocks using common clock framework
ARM: Kirkwood: Replace clock gating
ARM: Orion: Audio: Add clk/clkdev support
ARM: Orion: PCIE: Add support for clk
ARM: Orion: XOR: Add support for clk
ARM: Orion: CESA: Add support for clk
...
Diffstat (limited to 'drivers/clk/spear/clk-vco-pll.c')
-rw-r--r-- | drivers/clk/spear/clk-vco-pll.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/drivers/clk/spear/clk-vco-pll.c b/drivers/clk/spear/clk-vco-pll.c new file mode 100644 index 000000000000..dcd4bdf4b0d9 --- /dev/null +++ b/drivers/clk/spear/clk-vco-pll.c @@ -0,0 +1,363 @@ +/* + * Copyright (C) 2012 ST Microelectronics + * Viresh Kumar <viresh.kumar@st.com> + * + * 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. + * + * VCO-PLL clock implementation + */ + +#define pr_fmt(fmt) "clk-vco-pll: " fmt + +#include <linux/clk-provider.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> +#include "clk.h" + +/* + * DOC: VCO-PLL clock + * + * VCO and PLL rate are derived from following equations: + * + * In normal mode + * vco = (2 * M[15:8] * Fin)/N + * + * In Dithered mode + * vco = (2 * M[15:0] * Fin)/(256 * N) + * + * pll_rate = pll/2^p + * + * vco and pll are very closely bound to each other, "vco needs to program: + * mode, m & n" and "pll needs to program p", both share common enable/disable + * logic. + * + * clk_register_vco_pll() registers instances of both vco & pll. + * CLK_SET_RATE_PARENT flag is forced for pll, as it will always pass its + * set_rate to vco. A single rate table exists for both the clocks, which + * configures m, n and p. + */ + +/* PLL_CTR register masks */ +#define PLL_MODE_NORMAL 0 +#define PLL_MODE_FRACTION 1 +#define PLL_MODE_DITH_DSM 2 +#define PLL_MODE_DITH_SSM 3 +#define PLL_MODE_MASK 3 +#define PLL_MODE_SHIFT 3 +#define PLL_ENABLE 2 + +#define PLL_LOCK_SHIFT 0 +#define PLL_LOCK_MASK 1 + +/* PLL FRQ register masks */ +#define PLL_NORM_FDBK_M_MASK 0xFF +#define PLL_NORM_FDBK_M_SHIFT 24 +#define PLL_DITH_FDBK_M_MASK 0xFFFF +#define PLL_DITH_FDBK_M_SHIFT 16 +#define PLL_DIV_P_MASK 0x7 +#define PLL_DIV_P_SHIFT 8 +#define PLL_DIV_N_MASK 0xFF +#define PLL_DIV_N_SHIFT 0 + +#define to_clk_vco(_hw) container_of(_hw, struct clk_vco, hw) +#define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw) + +/* Calculates pll clk rate for specific value of mode, m, n and p */ +static unsigned long pll_calc_rate(struct pll_rate_tbl *rtbl, + unsigned long prate, int index, unsigned long *pll_rate) +{ + unsigned long rate = prate; + unsigned int mode; + + mode = rtbl[index].mode ? 256 : 1; + rate = (((2 * rate / 10000) * rtbl[index].m) / (mode * rtbl[index].n)); + + if (pll_rate) + *pll_rate = (rate / (1 << rtbl[index].p)) * 10000; + + return rate * 10000; +} + +static long clk_pll_round_rate_index(struct clk_hw *hw, unsigned long drate, + unsigned long *prate, int *index) +{ + struct clk_pll *pll = to_clk_pll(hw); + unsigned long prev_rate, vco_prev_rate, rate = 0; + unsigned long vco_parent_rate = + __clk_get_rate(__clk_get_parent(__clk_get_parent(hw->clk))); + + if (!prate) { + pr_err("%s: prate is must for pll clk\n", __func__); + return -EINVAL; + } + + for (*index = 0; *index < pll->vco->rtbl_cnt; (*index)++) { + prev_rate = rate; + vco_prev_rate = *prate; + *prate = pll_calc_rate(pll->vco->rtbl, vco_parent_rate, *index, + &rate); + if (drate < rate) { + /* previous clock was best */ + if (*index) { + rate = prev_rate; + *prate = vco_prev_rate; + (*index)--; + } + break; + } + } + + return rate; +} + +static long clk_pll_round_rate(struct clk_hw *hw, unsigned long drate, + unsigned long *prate) +{ + int unused; + + return clk_pll_round_rate_index(hw, drate, prate, &unused); +} + +static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, unsigned long + parent_rate) +{ + struct clk_pll *pll = to_clk_pll(hw); + unsigned long flags = 0; + unsigned int p; + + if (pll->vco->lock) + spin_lock_irqsave(pll->vco->lock, flags); + + p = readl_relaxed(pll->vco->cfg_reg); + + if (pll->vco->lock) + spin_unlock_irqrestore(pll->vco->lock, flags); + + p = (p >> PLL_DIV_P_SHIFT) & PLL_DIV_P_MASK; + + return parent_rate / (1 << p); +} + +static int clk_pll_set_rate(struct clk_hw *hw, unsigned long drate, + unsigned long prate) +{ + struct clk_pll *pll = to_clk_pll(hw); + struct pll_rate_tbl *rtbl = pll->vco->rtbl; + unsigned long flags = 0, val; + int i; + + clk_pll_round_rate_index(hw, drate, NULL, &i); + + if (pll->vco->lock) + spin_lock_irqsave(pll->vco->lock, flags); + + val = readl_relaxed(pll->vco->cfg_reg); + val &= ~(PLL_DIV_P_MASK << PLL_DIV_P_SHIFT); + val |= (rtbl[i].p & PLL_DIV_P_MASK) << PLL_DIV_P_SHIFT; + writel_relaxed(val, pll->vco->cfg_reg); + + if (pll->vco->lock) + spin_unlock_irqrestore(pll->vco->lock, flags); + + return 0; +} + +static struct clk_ops clk_pll_ops = { + .recalc_rate = clk_pll_recalc_rate, + .round_rate = clk_pll_round_rate, + .set_rate = clk_pll_set_rate, +}; + +static inline unsigned long vco_calc_rate(struct clk_hw *hw, + unsigned long prate, int index) +{ + struct clk_vco *vco = to_clk_vco(hw); + + return pll_calc_rate(vco->rtbl, prate, index, NULL); +} + +static long clk_vco_round_rate(struct clk_hw *hw, unsigned long drate, + unsigned long *prate) +{ + struct clk_vco *vco = to_clk_vco(hw); + int unused; + + return clk_round_rate_index(hw, drate, *prate, vco_calc_rate, + vco->rtbl_cnt, &unused); +} + +static unsigned long clk_vco_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_vco *vco = to_clk_vco(hw); + unsigned long flags = 0; + unsigned int num = 2, den = 0, val, mode = 0; + + if (vco->lock) + spin_lock_irqsave(vco->lock, flags); + + mode = (readl_relaxed(vco->mode_reg) >> PLL_MODE_SHIFT) & PLL_MODE_MASK; + + val = readl_relaxed(vco->cfg_reg); + + if (vco->lock) + spin_unlock_irqrestore(vco->lock, flags); + + den = (val >> PLL_DIV_N_SHIFT) & PLL_DIV_N_MASK; + + /* calculate numerator & denominator */ + if (!mode) { + /* Normal mode */ + num *= (val >> PLL_NORM_FDBK_M_SHIFT) & PLL_NORM_FDBK_M_MASK; + } else { + /* Dithered mode */ + num *= (val >> PLL_DITH_FDBK_M_SHIFT) & PLL_DITH_FDBK_M_MASK; + den *= 256; + } + + if (!den) { + WARN(1, "%s: denominator can't be zero\n", __func__); + return 0; + } + + return (((parent_rate / 10000) * num) / den) * 10000; +} + +/* Configures new clock rate of vco */ +static int clk_vco_set_rate(struct clk_hw *hw, unsigned long drate, + unsigned long prate) +{ + struct clk_vco *vco = to_clk_vco(hw); + struct pll_rate_tbl *rtbl = vco->rtbl; + unsigned long flags = 0, val; + int i; + + clk_round_rate_index(hw, drate, prate, vco_calc_rate, vco->rtbl_cnt, + &i); + + if (vco->lock) + spin_lock_irqsave(vco->lock, flags); + + val = readl_relaxed(vco->mode_reg); + val &= ~(PLL_MODE_MASK << PLL_MODE_SHIFT); + val |= (rtbl[i].mode & PLL_MODE_MASK) << PLL_MODE_SHIFT; + writel_relaxed(val, vco->mode_reg); + + val = readl_relaxed(vco->cfg_reg); + val &= ~(PLL_DIV_N_MASK << PLL_DIV_N_SHIFT); + val |= (rtbl[i].n & PLL_DIV_N_MASK) << PLL_DIV_N_SHIFT; + + val &= ~(PLL_DITH_FDBK_M_MASK << PLL_DITH_FDBK_M_SHIFT); + if (rtbl[i].mode) + val |= (rtbl[i].m & PLL_DITH_FDBK_M_MASK) << + PLL_DITH_FDBK_M_SHIFT; + else + val |= (rtbl[i].m & PLL_NORM_FDBK_M_MASK) << + PLL_NORM_FDBK_M_SHIFT; + + writel_relaxed(val, vco->cfg_reg); + + if (vco->lock) + spin_unlock_irqrestore(vco->lock, flags); + + return 0; +} + +static struct clk_ops clk_vco_ops = { + .recalc_rate = clk_vco_recalc_rate, + .round_rate = clk_vco_round_rate, + .set_rate = clk_vco_set_rate, +}; + +struct clk *clk_register_vco_pll(const char *vco_name, const char *pll_name, + const char *vco_gate_name, const char *parent_name, + unsigned long flags, void __iomem *mode_reg, void __iomem + *cfg_reg, struct pll_rate_tbl *rtbl, u8 rtbl_cnt, + spinlock_t *lock, struct clk **pll_clk, + struct clk **vco_gate_clk) +{ + struct clk_vco *vco; + struct clk_pll *pll; + struct clk *vco_clk, *tpll_clk, *tvco_gate_clk; + struct clk_init_data vco_init, pll_init; + const char **vco_parent_name; + + if (!vco_name || !pll_name || !parent_name || !mode_reg || !cfg_reg || + !rtbl || !rtbl_cnt) { + pr_err("Invalid arguments passed"); + return ERR_PTR(-EINVAL); + } + + vco = kzalloc(sizeof(*vco), GFP_KERNEL); + if (!vco) { + pr_err("could not allocate vco clk\n"); + return ERR_PTR(-ENOMEM); + } + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) { + pr_err("could not allocate pll clk\n"); + goto free_vco; + } + + /* struct clk_vco assignments */ + vco->mode_reg = mode_reg; + vco->cfg_reg = cfg_reg; + vco->rtbl = rtbl; + vco->rtbl_cnt = rtbl_cnt; + vco->lock = lock; + vco->hw.init = &vco_init; + + pll->vco = vco; + pll->hw.init = &pll_init; + + if (vco_gate_name) { + tvco_gate_clk = clk_register_gate(NULL, vco_gate_name, + parent_name, 0, mode_reg, PLL_ENABLE, 0, lock); + if (IS_ERR_OR_NULL(tvco_gate_clk)) + goto free_pll; + + if (vco_gate_clk) + *vco_gate_clk = tvco_gate_clk; + vco_parent_name = &vco_gate_name; + } else { + vco_parent_name = &parent_name; + } + + vco_init.name = vco_name; + vco_init.ops = &clk_vco_ops; + vco_init.flags = flags; + vco_init.parent_names = vco_parent_name; + vco_init.num_parents = 1; + + pll_init.name = pll_name; + pll_init.ops = &clk_pll_ops; + pll_init.flags = CLK_SET_RATE_PARENT; + pll_init.parent_names = &vco_name; + pll_init.num_parents = 1; + + vco_clk = clk_register(NULL, &vco->hw); + if (IS_ERR_OR_NULL(vco_clk)) + goto free_pll; + + tpll_clk = clk_register(NULL, &pll->hw); + if (IS_ERR_OR_NULL(tpll_clk)) + goto free_pll; + + if (pll_clk) + *pll_clk = tpll_clk; + + return vco_clk; + +free_pll: + kfree(pll); +free_vco: + kfree(vco); + + pr_err("Failed to register vco pll clock\n"); + + return ERR_PTR(-ENOMEM); +} |