diff options
Diffstat (limited to 'drivers/staging/media/deprecated/atmel/atmel-isc-clk.c')
-rw-r--r-- | drivers/staging/media/deprecated/atmel/atmel-isc-clk.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/staging/media/deprecated/atmel/atmel-isc-clk.c b/drivers/staging/media/deprecated/atmel/atmel-isc-clk.c new file mode 100644 index 000000000000..d442b5f4c931 --- /dev/null +++ b/drivers/staging/media/deprecated/atmel/atmel-isc-clk.c @@ -0,0 +1,311 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Microchip Image Sensor Controller (ISC) common clock driver setup + * + * Copyright (C) 2016 Microchip Technology, Inc. + * + * Author: Songjun Wu + * Author: Eugen Hristev <eugen.hristev@microchip.com> + * + */ +#include <linux/clk.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> + +#include "atmel-isc-regs.h" +#include "atmel-isc.h" + +static int isc_wait_clk_stable(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + struct regmap *regmap = isc_clk->regmap; + unsigned long timeout = jiffies + usecs_to_jiffies(1000); + unsigned int status; + + while (time_before(jiffies, timeout)) { + regmap_read(regmap, ISC_CLKSR, &status); + if (!(status & ISC_CLKSR_SIP)) + return 0; + + usleep_range(10, 250); + } + + return -ETIMEDOUT; +} + +static int isc_clk_prepare(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + int ret; + + ret = pm_runtime_resume_and_get(isc_clk->dev); + if (ret < 0) + return ret; + + return isc_wait_clk_stable(hw); +} + +static void isc_clk_unprepare(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + + isc_wait_clk_stable(hw); + + pm_runtime_put_sync(isc_clk->dev); +} + +static int isc_clk_enable(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + u32 id = isc_clk->id; + struct regmap *regmap = isc_clk->regmap; + unsigned long flags; + unsigned int status; + + dev_dbg(isc_clk->dev, "ISC CLK: %s, id = %d, div = %d, parent id = %d\n", + __func__, id, isc_clk->div, isc_clk->parent_id); + + spin_lock_irqsave(&isc_clk->lock, flags); + regmap_update_bits(regmap, ISC_CLKCFG, + ISC_CLKCFG_DIV_MASK(id) | ISC_CLKCFG_SEL_MASK(id), + (isc_clk->div << ISC_CLKCFG_DIV_SHIFT(id)) | + (isc_clk->parent_id << ISC_CLKCFG_SEL_SHIFT(id))); + + regmap_write(regmap, ISC_CLKEN, ISC_CLK(id)); + spin_unlock_irqrestore(&isc_clk->lock, flags); + + regmap_read(regmap, ISC_CLKSR, &status); + if (status & ISC_CLK(id)) + return 0; + else + return -EINVAL; +} + +static void isc_clk_disable(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + u32 id = isc_clk->id; + unsigned long flags; + + spin_lock_irqsave(&isc_clk->lock, flags); + regmap_write(isc_clk->regmap, ISC_CLKDIS, ISC_CLK(id)); + spin_unlock_irqrestore(&isc_clk->lock, flags); +} + +static int isc_clk_is_enabled(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + u32 status; + int ret; + + ret = pm_runtime_resume_and_get(isc_clk->dev); + if (ret < 0) + return 0; + + regmap_read(isc_clk->regmap, ISC_CLKSR, &status); + + pm_runtime_put_sync(isc_clk->dev); + + return status & ISC_CLK(isc_clk->id) ? 1 : 0; +} + +static unsigned long +isc_clk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + + return DIV_ROUND_CLOSEST(parent_rate, isc_clk->div + 1); +} + +static int isc_clk_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + long best_rate = -EINVAL; + int best_diff = -1; + unsigned int i, div; + + for (i = 0; i < clk_hw_get_num_parents(hw); i++) { + struct clk_hw *parent; + unsigned long parent_rate; + + parent = clk_hw_get_parent_by_index(hw, i); + if (!parent) + continue; + + parent_rate = clk_hw_get_rate(parent); + if (!parent_rate) + continue; + + for (div = 1; div < ISC_CLK_MAX_DIV + 2; div++) { + unsigned long rate; + int diff; + + rate = DIV_ROUND_CLOSEST(parent_rate, div); + diff = abs(req->rate - rate); + + if (best_diff < 0 || best_diff > diff) { + best_rate = rate; + best_diff = diff; + req->best_parent_rate = parent_rate; + req->best_parent_hw = parent; + } + + if (!best_diff || rate < req->rate) + break; + } + + if (!best_diff) + break; + } + + dev_dbg(isc_clk->dev, + "ISC CLK: %s, best_rate = %ld, parent clk: %s @ %ld\n", + __func__, best_rate, + __clk_get_name((req->best_parent_hw)->clk), + req->best_parent_rate); + + if (best_rate < 0) + return best_rate; + + req->rate = best_rate; + + return 0; +} + +static int isc_clk_set_parent(struct clk_hw *hw, u8 index) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + + if (index >= clk_hw_get_num_parents(hw)) + return -EINVAL; + + isc_clk->parent_id = index; + + return 0; +} + +static u8 isc_clk_get_parent(struct clk_hw *hw) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + + return isc_clk->parent_id; +} + +static int isc_clk_set_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate) +{ + struct isc_clk *isc_clk = to_isc_clk(hw); + u32 div; + + if (!rate) + return -EINVAL; + + div = DIV_ROUND_CLOSEST(parent_rate, rate); + if (div > (ISC_CLK_MAX_DIV + 1) || !div) + return -EINVAL; + + isc_clk->div = div - 1; + + return 0; +} + +static const struct clk_ops isc_clk_ops = { + .prepare = isc_clk_prepare, + .unprepare = isc_clk_unprepare, + .enable = isc_clk_enable, + .disable = isc_clk_disable, + .is_enabled = isc_clk_is_enabled, + .recalc_rate = isc_clk_recalc_rate, + .determine_rate = isc_clk_determine_rate, + .set_parent = isc_clk_set_parent, + .get_parent = isc_clk_get_parent, + .set_rate = isc_clk_set_rate, +}; + +static int isc_clk_register(struct isc_device *isc, unsigned int id) +{ + struct regmap *regmap = isc->regmap; + struct device_node *np = isc->dev->of_node; + struct isc_clk *isc_clk; + struct clk_init_data init; + const char *clk_name = np->name; + const char *parent_names[3]; + int num_parents; + + if (id == ISC_ISPCK && !isc->ispck_required) + return 0; + + num_parents = of_clk_get_parent_count(np); + if (num_parents < 1 || num_parents > 3) + return -EINVAL; + + if (num_parents > 2 && id == ISC_ISPCK) + num_parents = 2; + + of_clk_parent_fill(np, parent_names, num_parents); + + if (id == ISC_MCK) + of_property_read_string(np, "clock-output-names", &clk_name); + else + clk_name = "isc-ispck"; + + init.parent_names = parent_names; + init.num_parents = num_parents; + init.name = clk_name; + init.ops = &isc_clk_ops; + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; + + isc_clk = &isc->isc_clks[id]; + isc_clk->hw.init = &init; + isc_clk->regmap = regmap; + isc_clk->id = id; + isc_clk->dev = isc->dev; + spin_lock_init(&isc_clk->lock); + + isc_clk->clk = clk_register(isc->dev, &isc_clk->hw); + if (IS_ERR(isc_clk->clk)) { + dev_err(isc->dev, "%s: clock register fail\n", clk_name); + return PTR_ERR(isc_clk->clk); + } else if (id == ISC_MCK) { + of_clk_add_provider(np, of_clk_src_simple_get, isc_clk->clk); + } + + return 0; +} + +int atmel_isc_clk_init(struct isc_device *isc) +{ + unsigned int i; + int ret; + + for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) + isc->isc_clks[i].clk = ERR_PTR(-EINVAL); + + for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) { + ret = isc_clk_register(isc, i); + if (ret) + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(atmel_isc_clk_init); + +void atmel_isc_clk_cleanup(struct isc_device *isc) +{ + unsigned int i; + + of_clk_del_provider(isc->dev->of_node); + + for (i = 0; i < ARRAY_SIZE(isc->isc_clks); i++) { + struct isc_clk *isc_clk = &isc->isc_clks[i]; + + if (!IS_ERR(isc_clk->clk)) + clk_unregister(isc_clk->clk); + } +} +EXPORT_SYMBOL_GPL(atmel_isc_clk_cleanup); |