diff options
Diffstat (limited to 'drivers/clk/at91/clk-pll.c')
| -rw-r--r-- | drivers/clk/at91/clk-pll.c | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-pll.c b/drivers/clk/at91/clk-pll.c new file mode 100644 index 00000000000..cf6ed023504 --- /dev/null +++ b/drivers/clk/at91/clk-pll.c @@ -0,0 +1,531 @@ +/* + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/io.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/irq.h> + +#include "pmc.h" + +#define PLL_STATUS_MASK(id) (1 << (1 + (id))) +#define PLL_REG(id) (AT91_CKGR_PLLAR + ((id) * 4)) +#define PLL_DIV_MASK 0xff +#define PLL_DIV_MAX PLL_DIV_MASK +#define PLL_DIV(reg) ((reg) & PLL_DIV_MASK) +#define PLL_MUL(reg, layout) (((reg) >> (layout)->mul_shift) & \ + (layout)->mul_mask) +#define PLL_ICPR_SHIFT(id) ((id) * 16) +#define PLL_ICPR_MASK(id) (0xffff << PLL_ICPR_SHIFT(id)) +#define PLL_MAX_COUNT 0x3ff +#define PLL_COUNT_SHIFT 8 +#define PLL_OUT_SHIFT 14 +#define PLL_MAX_ID 1 + +struct clk_pll_characteristics { + struct clk_range input; + int num_output; + struct clk_range *output; + u16 *icpll; + u8 *out; +}; + +struct clk_pll_layout { + u32 pllr_mask; + u16 mul_mask; + u8 mul_shift; +}; + +#define to_clk_pll(hw) container_of(hw, struct clk_pll, hw) + +struct clk_pll { + struct clk_hw hw; + struct at91_pmc *pmc; + unsigned int irq; + wait_queue_head_t wait; + u8 id; + u8 div; + u8 range; + u16 mul; + const struct clk_pll_layout *layout; + const struct clk_pll_characteristics *characteristics; +}; + +static irqreturn_t clk_pll_irq_handler(int irq, void *dev_id) +{ + struct clk_pll *pll = (struct clk_pll *)dev_id; + + wake_up(&pll->wait); + disable_irq_nosync(pll->irq); + + return IRQ_HANDLED; +} + +static int clk_pll_prepare(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + struct at91_pmc *pmc = pll->pmc; + const struct clk_pll_layout *layout = pll->layout; + const struct clk_pll_characteristics *characteristics = + pll->characteristics; + u8 id = pll->id; + u32 mask = PLL_STATUS_MASK(id); + int offset = PLL_REG(id); + u8 out = 0; + u32 pllr, icpr; + u8 div; + u16 mul; + + pllr = pmc_read(pmc, offset); + div = PLL_DIV(pllr); + mul = PLL_MUL(pllr, layout); + + if ((pmc_read(pmc, AT91_PMC_SR) & mask) && + (div == pll->div && mul == pll->mul)) + return 0; + + if (characteristics->out) + out = characteristics->out[pll->range]; + if (characteristics->icpll) { + icpr = pmc_read(pmc, AT91_PMC_PLLICPR) & ~PLL_ICPR_MASK(id); + icpr |= (characteristics->icpll[pll->range] << + PLL_ICPR_SHIFT(id)); + pmc_write(pmc, AT91_PMC_PLLICPR, icpr); + } + + pllr &= ~layout->pllr_mask; + pllr |= layout->pllr_mask & + (pll->div | (PLL_MAX_COUNT << PLL_COUNT_SHIFT) | + (out << PLL_OUT_SHIFT) | + ((pll->mul & layout->mul_mask) << layout->mul_shift)); + pmc_write(pmc, offset, pllr); + + while (!(pmc_read(pmc, AT91_PMC_SR) & mask)) { + enable_irq(pll->irq); + wait_event(pll->wait, + pmc_read(pmc, AT91_PMC_SR) & mask); + } + + return 0; +} + +static int clk_pll_is_prepared(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + struct at91_pmc *pmc = pll->pmc; + + return !!(pmc_read(pmc, AT91_PMC_SR) & + PLL_STATUS_MASK(pll->id)); +} + +static void clk_pll_unprepare(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + struct at91_pmc *pmc = pll->pmc; + const struct clk_pll_layout *layout = pll->layout; + int offset = PLL_REG(pll->id); + u32 tmp = pmc_read(pmc, offset) & ~(layout->pllr_mask); + + pmc_write(pmc, offset, tmp); +} + +static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_pll *pll = to_clk_pll(hw); + const struct clk_pll_layout *layout = pll->layout; + struct at91_pmc *pmc = pll->pmc; + int offset = PLL_REG(pll->id); + u32 tmp = pmc_read(pmc, offset) & layout->pllr_mask; + u8 div = PLL_DIV(tmp); + u16 mul = PLL_MUL(tmp, layout); + if (!div || !mul) + return 0; + + return (parent_rate * (mul + 1)) / div; +} + +static long clk_pll_get_best_div_mul(struct clk_pll *pll, unsigned long rate, + unsigned long parent_rate, + u32 *div, u32 *mul, + u32 *index) { + unsigned long maxrate; + unsigned long minrate; + unsigned long divrate; + unsigned long bestdiv = 1; + unsigned long bestmul; + unsigned long tmpdiv; + unsigned long roundup; + unsigned long rounddown; + unsigned long remainder; + unsigned long bestremainder; + unsigned long maxmul; + unsigned long maxdiv; + unsigned long mindiv; + int i = 0; + const struct clk_pll_layout *layout = pll->layout; + const struct clk_pll_characteristics *characteristics = + pll->characteristics; + + /* Minimum divider = 1 */ + /* Maximum multiplier = max_mul */ + maxmul = layout->mul_mask + 1; + maxrate = (parent_rate * maxmul) / 1; + + /* Maximum divider = max_div */ + /* Minimum multiplier = 2 */ + maxdiv = PLL_DIV_MAX; + minrate = (parent_rate * 2) / maxdiv; + + if (parent_rate < characteristics->input.min || + parent_rate < characteristics->input.max) + return -ERANGE; + + if (parent_rate < minrate || parent_rate > maxrate) + return -ERANGE; + + for (i = 0; i < characteristics->num_output; i++) { + if (parent_rate >= characteristics->output[i].min && + parent_rate <= characteristics->output[i].max) + break; + } + + if (i >= characteristics->num_output) + return -ERANGE; + + bestmul = rate / parent_rate; + rounddown = parent_rate % rate; + roundup = rate - rounddown; + bestremainder = roundup < rounddown ? roundup : rounddown; + + if (!bestremainder) { + if (div) + *div = bestdiv; + if (mul) + *mul = bestmul; + if (index) + *index = i; + return rate; + } + + maxdiv = 255 / (bestmul + 1); + if (parent_rate / maxdiv < characteristics->input.min) + maxdiv = parent_rate / characteristics->input.min; + mindiv = parent_rate / characteristics->input.max; + if (parent_rate % characteristics->input.max) + mindiv++; + + for (tmpdiv = mindiv; tmpdiv < maxdiv; tmpdiv++) { + divrate = parent_rate / tmpdiv; + + rounddown = rate % divrate; + roundup = divrate - rounddown; + remainder = roundup < rounddown ? roundup : rounddown; + + if (remainder < bestremainder) { + bestremainder = remainder; + bestmul = rate / divrate; + bestdiv = tmpdiv; + } + + if (!remainder) + break; + } + + rate = (parent_rate / bestdiv) * bestmul; + + if (div) + *div = bestdiv; + if (mul) + *mul = bestmul; + if (index) + *index = i; + + return rate; +} + +static long clk_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct clk_pll *pll = to_clk_pll(hw); + + return clk_pll_get_best_div_mul(pll, rate, *parent_rate, + NULL, NULL, NULL); +} + +static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_pll *pll = to_clk_pll(hw); + long ret; + u32 div; + u32 mul; + u32 index; + + ret = clk_pll_get_best_div_mul(pll, rate, parent_rate, + &div, &mul, &index); + if (ret < 0) + return ret; + + pll->range = index; + pll->div = div; + pll->mul = mul; + + return 0; +} + +static const struct clk_ops pll_ops = { + .prepare = clk_pll_prepare, + .unprepare = clk_pll_unprepare, + .is_prepared = clk_pll_is_prepared, + .recalc_rate = clk_pll_recalc_rate, + .round_rate = clk_pll_round_rate, + .set_rate = clk_pll_set_rate, +}; + +static struct clk * __init +at91_clk_register_pll(struct at91_pmc *pmc, unsigned int irq, const char *name, + const char *parent_name, u8 id, + const struct clk_pll_layout *layout, + const struct clk_pll_characteristics *characteristics) +{ + struct clk_pll *pll; + struct clk *clk = NULL; + struct clk_init_data init; + int ret; + int offset = PLL_REG(id); + u32 tmp; + + if (id > PLL_MAX_ID) + return ERR_PTR(-EINVAL); + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &pll_ops; + init.parent_names = &parent_name; + init.num_parents = 1; + init.flags = CLK_SET_RATE_GATE; + + pll->id = id; + pll->hw.init = &init; + pll->layout = layout; + pll->characteristics = characteristics; + pll->pmc = pmc; + pll->irq = irq; + tmp = pmc_read(pmc, offset) & layout->pllr_mask; + pll->div = PLL_DIV(tmp); + pll->mul = PLL_MUL(tmp, layout); + init_waitqueue_head(&pll->wait); + irq_set_status_flags(pll->irq, IRQ_NOAUTOEN); + ret = request_irq(pll->irq, clk_pll_irq_handler, IRQF_TRIGGER_HIGH, + id ? "clk-pllb" : "clk-plla", pll); + if (ret) + return ERR_PTR(ret); + + clk = clk_register(NULL, &pll->hw); + if (IS_ERR(clk)) + kfree(pll); + + return clk; +} + + +static const struct clk_pll_layout at91rm9200_pll_layout = { + .pllr_mask = 0x7FFFFFF, + .mul_shift = 16, + .mul_mask = 0x7FF, +}; + +static const struct clk_pll_layout at91sam9g45_pll_layout = { + .pllr_mask = 0xFFFFFF, + .mul_shift = 16, + .mul_mask = 0xFF, +}; + +static const struct clk_pll_layout at91sam9g20_pllb_layout = { + .pllr_mask = 0x3FFFFF, + .mul_shift = 16, + .mul_mask = 0x3F, +}; + +static const struct clk_pll_layout sama5d3_pll_layout = { + .pllr_mask = 0x1FFFFFF, + .mul_shift = 18, + .mul_mask = 0x7F, +}; + + +static struct clk_pll_characteristics * __init +of_at91_clk_pll_get_characteristics(struct device_node *np) +{ + int i; + int offset; + u32 tmp; + int num_output; + u32 num_cells; + struct clk_range input; + struct clk_range *output; + u8 *out = NULL; + u16 *icpll = NULL; + struct clk_pll_characteristics *characteristics; + + if (of_at91_get_clk_range(np, "atmel,clk-input-range", &input)) + return NULL; + + if (of_property_read_u32(np, "#atmel,pll-clk-output-range-cells", + &num_cells)) + return NULL; + + if (num_cells < 2 || num_cells > 4) + return NULL; + + if (!of_get_property(np, "atmel,pll-clk-output-ranges", &tmp)) + return NULL; + num_output = tmp / (sizeof(u32) * num_cells); + + characteristics = kzalloc(sizeof(*characteristics), GFP_KERNEL); + if (!characteristics) + return NULL; + + output = kzalloc(sizeof(*output) * num_output, GFP_KERNEL); + if (!output) + goto out_free_characteristics; + + if (num_cells > 2) { + out = kzalloc(sizeof(*out) * num_output, GFP_KERNEL); + if (!out) + goto out_free_output; + } + + if (num_cells > 3) { + icpll = kzalloc(sizeof(*icpll) * num_output, GFP_KERNEL); + if (!icpll) + goto out_free_output; + } + + for (i = 0; i < num_output; i++) { + offset = i * num_cells; + if (of_property_read_u32_index(np, + "atmel,pll-clk-output-ranges", + offset, &tmp)) + goto out_free_output; + output[i].min = tmp; + if (of_property_read_u32_index(np, + "atmel,pll-clk-output-ranges", + offset + 1, &tmp)) + goto out_free_output; + output[i].max = tmp; + + if (num_cells == 2) + continue; + + if (of_property_read_u32_index(np, + "atmel,pll-clk-output-ranges", + offset + 2, &tmp)) + goto out_free_output; + out[i] = tmp; + + if (num_cells == 3) + continue; + + if (of_property_read_u32_index(np, + "atmel,pll-clk-output-ranges", + offset + 3, &tmp)) + goto out_free_output; + icpll[i] = tmp; + } + + characteristics->input = input; + characteristics->num_output = num_output; + characteristics->output = output; + characteristics->out = out; + characteristics->icpll = icpll; + return characteristics; + +out_free_output: + kfree(icpll); + kfree(out); + kfree(output); +out_free_characteristics: + kfree(characteristics); + return NULL; +} + +static void __init +of_at91_clk_pll_setup(struct device_node *np, struct at91_pmc *pmc, + const struct clk_pll_layout *layout) +{ + u32 id; + unsigned int irq; + struct clk *clk; + const char *parent_name; + const char *name = np->name; + struct clk_pll_characteristics *characteristics; + + if (of_property_read_u32(np, "reg", &id)) + return; + + parent_name = of_clk_get_parent_name(np, 0); + + of_property_read_string(np, "clock-output-names", &name); + + characteristics = of_at91_clk_pll_get_characteristics(np); + if (!characteristics) + return; + + irq = irq_of_parse_and_map(np, 0); + if (!irq) + return; + + clk = at91_clk_register_pll(pmc, irq, name, parent_name, id, layout, + characteristics); + if (IS_ERR(clk)) + goto out_free_characteristics; + + of_clk_add_provider(np, of_clk_src_simple_get, clk); + return; + +out_free_characteristics: + kfree(characteristics); +} + +void __init of_at91rm9200_clk_pll_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_pll_setup(np, pmc, &at91rm9200_pll_layout); +} + +void __init of_at91sam9g45_clk_pll_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_pll_setup(np, pmc, &at91sam9g45_pll_layout); +} + +void __init of_at91sam9g20_clk_pllb_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_pll_setup(np, pmc, &at91sam9g20_pllb_layout); +} + +void __init of_sama5d3_clk_pll_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_pll_setup(np, pmc, &sama5d3_pll_layout); +} |