diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/clk-hsdk-pll.c | 437 |
1 files changed, 437 insertions, 0 deletions
diff --git a/drivers/clk/clk-hsdk-pll.c b/drivers/clk/clk-hsdk-pll.c new file mode 100644 index 000000000..60007b508 --- /dev/null +++ b/drivers/clk/clk-hsdk-pll.c @@ -0,0 +1,437 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Synopsys HSDK SDP Generic PLL clock driver + * + * Copyright (C) 2017 Synopsys + */ + +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#define CGU_PLL_CTRL 0x000 /* ARC PLL control register */ +#define CGU_PLL_STATUS 0x004 /* ARC PLL status register */ +#define CGU_PLL_FMEAS 0x008 /* ARC PLL frequency measurement register */ +#define CGU_PLL_MON 0x00C /* ARC PLL monitor register */ + +#define CGU_PLL_CTRL_ODIV_SHIFT 2 +#define CGU_PLL_CTRL_IDIV_SHIFT 4 +#define CGU_PLL_CTRL_FBDIV_SHIFT 9 +#define CGU_PLL_CTRL_BAND_SHIFT 20 + +#define CGU_PLL_CTRL_ODIV_MASK GENMASK(3, CGU_PLL_CTRL_ODIV_SHIFT) +#define CGU_PLL_CTRL_IDIV_MASK GENMASK(8, CGU_PLL_CTRL_IDIV_SHIFT) +#define CGU_PLL_CTRL_FBDIV_MASK GENMASK(15, CGU_PLL_CTRL_FBDIV_SHIFT) + +#define CGU_PLL_CTRL_PD BIT(0) +#define CGU_PLL_CTRL_BYPASS BIT(1) + +#define CGU_PLL_STATUS_LOCK BIT(0) +#define CGU_PLL_STATUS_ERR BIT(1) + +#define HSDK_PLL_MAX_LOCK_TIME 100 /* 100 us */ + +#define CGU_PLL_SOURCE_MAX 1 + +#define CORE_IF_CLK_THRESHOLD_HZ 500000000 +#define CREG_CORE_IF_CLK_DIV_1 0x0 +#define CREG_CORE_IF_CLK_DIV_2 0x1 + +struct hsdk_pll_cfg { + u32 rate; + u32 idiv; + u32 fbdiv; + u32 odiv; + u32 band; + u32 bypass; +}; + +static const struct hsdk_pll_cfg asdt_pll_cfg[] = { + { 100000000, 0, 11, 3, 0, 0 }, + { 133000000, 0, 15, 3, 0, 0 }, + { 200000000, 1, 47, 3, 0, 0 }, + { 233000000, 1, 27, 2, 0, 0 }, + { 300000000, 1, 35, 2, 0, 0 }, + { 333000000, 1, 39, 2, 0, 0 }, + { 400000000, 1, 47, 2, 0, 0 }, + { 500000000, 0, 14, 1, 0, 0 }, + { 600000000, 0, 17, 1, 0, 0 }, + { 700000000, 0, 20, 1, 0, 0 }, + { 800000000, 0, 23, 1, 0, 0 }, + { 900000000, 1, 26, 0, 0, 0 }, + { 1000000000, 1, 29, 0, 0, 0 }, + { 1100000000, 1, 32, 0, 0, 0 }, + { 1200000000, 1, 35, 0, 0, 0 }, + { 1300000000, 1, 38, 0, 0, 0 }, + { 1400000000, 1, 41, 0, 0, 0 }, + { 1500000000, 1, 44, 0, 0, 0 }, + { 1600000000, 1, 47, 0, 0, 0 }, + {} +}; + +static const struct hsdk_pll_cfg hdmi_pll_cfg[] = { + { 27000000, 0, 0, 0, 0, 1 }, + { 148500000, 0, 21, 3, 0, 0 }, + { 297000000, 0, 21, 2, 0, 0 }, + { 540000000, 0, 19, 1, 0, 0 }, + { 594000000, 0, 21, 1, 0, 0 }, + {} +}; + +struct hsdk_pll_clk { + struct clk_hw hw; + void __iomem *regs; + void __iomem *spec_regs; + const struct hsdk_pll_devdata *pll_devdata; + struct device *dev; +}; + +struct hsdk_pll_devdata { + const struct hsdk_pll_cfg *pll_cfg; + int (*update_rate)(struct hsdk_pll_clk *clk, unsigned long rate, + const struct hsdk_pll_cfg *cfg); +}; + +static int hsdk_pll_core_update_rate(struct hsdk_pll_clk *, unsigned long, + const struct hsdk_pll_cfg *); +static int hsdk_pll_comm_update_rate(struct hsdk_pll_clk *, unsigned long, + const struct hsdk_pll_cfg *); + +static const struct hsdk_pll_devdata core_pll_devdata = { + .pll_cfg = asdt_pll_cfg, + .update_rate = hsdk_pll_core_update_rate, +}; + +static const struct hsdk_pll_devdata sdt_pll_devdata = { + .pll_cfg = asdt_pll_cfg, + .update_rate = hsdk_pll_comm_update_rate, +}; + +static const struct hsdk_pll_devdata hdmi_pll_devdata = { + .pll_cfg = hdmi_pll_cfg, + .update_rate = hsdk_pll_comm_update_rate, +}; + +static inline void hsdk_pll_write(struct hsdk_pll_clk *clk, u32 reg, u32 val) +{ + iowrite32(val, clk->regs + reg); +} + +static inline u32 hsdk_pll_read(struct hsdk_pll_clk *clk, u32 reg) +{ + return ioread32(clk->regs + reg); +} + +static inline void hsdk_pll_set_cfg(struct hsdk_pll_clk *clk, + const struct hsdk_pll_cfg *cfg) +{ + u32 val = 0; + + if (cfg->bypass) { + val = hsdk_pll_read(clk, CGU_PLL_CTRL); + val |= CGU_PLL_CTRL_BYPASS; + } else { + /* Powerdown and Bypass bits should be cleared */ + val |= cfg->idiv << CGU_PLL_CTRL_IDIV_SHIFT; + val |= cfg->fbdiv << CGU_PLL_CTRL_FBDIV_SHIFT; + val |= cfg->odiv << CGU_PLL_CTRL_ODIV_SHIFT; + val |= cfg->band << CGU_PLL_CTRL_BAND_SHIFT; + } + + dev_dbg(clk->dev, "write configuration: %#x\n", val); + + hsdk_pll_write(clk, CGU_PLL_CTRL, val); +} + +static inline bool hsdk_pll_is_locked(struct hsdk_pll_clk *clk) +{ + return !!(hsdk_pll_read(clk, CGU_PLL_STATUS) & CGU_PLL_STATUS_LOCK); +} + +static inline bool hsdk_pll_is_err(struct hsdk_pll_clk *clk) +{ + return !!(hsdk_pll_read(clk, CGU_PLL_STATUS) & CGU_PLL_STATUS_ERR); +} + +static inline struct hsdk_pll_clk *to_hsdk_pll_clk(struct clk_hw *hw) +{ + return container_of(hw, struct hsdk_pll_clk, hw); +} + +static unsigned long hsdk_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + u32 val; + u64 rate; + u32 idiv, fbdiv, odiv; + struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw); + + val = hsdk_pll_read(clk, CGU_PLL_CTRL); + + dev_dbg(clk->dev, "current configuration: %#x\n", val); + + /* Check if PLL is bypassed */ + if (val & CGU_PLL_CTRL_BYPASS) + return parent_rate; + + /* Check if PLL is disabled */ + if (val & CGU_PLL_CTRL_PD) + return 0; + + /* input divider = reg.idiv + 1 */ + idiv = 1 + ((val & CGU_PLL_CTRL_IDIV_MASK) >> CGU_PLL_CTRL_IDIV_SHIFT); + /* fb divider = 2*(reg.fbdiv + 1) */ + fbdiv = 2 * (1 + ((val & CGU_PLL_CTRL_FBDIV_MASK) >> CGU_PLL_CTRL_FBDIV_SHIFT)); + /* output divider = 2^(reg.odiv) */ + odiv = 1 << ((val & CGU_PLL_CTRL_ODIV_MASK) >> CGU_PLL_CTRL_ODIV_SHIFT); + + rate = (u64)parent_rate * fbdiv; + do_div(rate, idiv * odiv); + + return rate; +} + +static long hsdk_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + int i; + unsigned long best_rate; + struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw); + const struct hsdk_pll_cfg *pll_cfg = clk->pll_devdata->pll_cfg; + + if (pll_cfg[0].rate == 0) + return -EINVAL; + + best_rate = pll_cfg[0].rate; + + for (i = 1; pll_cfg[i].rate != 0; i++) { + if (abs(rate - pll_cfg[i].rate) < abs(rate - best_rate)) + best_rate = pll_cfg[i].rate; + } + + dev_dbg(clk->dev, "chosen best rate: %lu\n", best_rate); + + return best_rate; +} + +static int hsdk_pll_comm_update_rate(struct hsdk_pll_clk *clk, + unsigned long rate, + const struct hsdk_pll_cfg *cfg) +{ + hsdk_pll_set_cfg(clk, cfg); + + /* + * Wait until CGU relocks and check error status. + * If after timeout CGU is unlocked yet return error. + */ + udelay(HSDK_PLL_MAX_LOCK_TIME); + if (!hsdk_pll_is_locked(clk)) + return -ETIMEDOUT; + + if (hsdk_pll_is_err(clk)) + return -EINVAL; + + return 0; +} + +static int hsdk_pll_core_update_rate(struct hsdk_pll_clk *clk, + unsigned long rate, + const struct hsdk_pll_cfg *cfg) +{ + /* + * When core clock exceeds 500MHz, the divider for the interface + * clock must be programmed to div-by-2. + */ + if (rate > CORE_IF_CLK_THRESHOLD_HZ) + iowrite32(CREG_CORE_IF_CLK_DIV_2, clk->spec_regs); + + hsdk_pll_set_cfg(clk, cfg); + + /* + * Wait until CGU relocks and check error status. + * If after timeout CGU is unlocked yet return error. + */ + udelay(HSDK_PLL_MAX_LOCK_TIME); + if (!hsdk_pll_is_locked(clk)) + return -ETIMEDOUT; + + if (hsdk_pll_is_err(clk)) + return -EINVAL; + + /* + * Program divider to div-by-1 if we succesfuly set core clock below + * 500MHz threshold. + */ + if (rate <= CORE_IF_CLK_THRESHOLD_HZ) + iowrite32(CREG_CORE_IF_CLK_DIV_1, clk->spec_regs); + + return 0; +} + +static int hsdk_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + int i; + struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw); + const struct hsdk_pll_cfg *pll_cfg = clk->pll_devdata->pll_cfg; + + for (i = 0; pll_cfg[i].rate != 0; i++) { + if (pll_cfg[i].rate == rate) { + return clk->pll_devdata->update_rate(clk, rate, + &pll_cfg[i]); + } + } + + dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate, + parent_rate); + + return -EINVAL; +} + +static const struct clk_ops hsdk_pll_ops = { + .recalc_rate = hsdk_pll_recalc_rate, + .round_rate = hsdk_pll_round_rate, + .set_rate = hsdk_pll_set_rate, +}; + +static int hsdk_pll_clk_probe(struct platform_device *pdev) +{ + int ret; + struct resource *mem; + const char *parent_name; + unsigned int num_parents; + struct hsdk_pll_clk *pll_clk; + struct clk_init_data init = { }; + struct device *dev = &pdev->dev; + + pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL); + if (!pll_clk) + return -ENOMEM; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pll_clk->regs = devm_ioremap_resource(dev, mem); + if (IS_ERR(pll_clk->regs)) + return PTR_ERR(pll_clk->regs); + + init.name = dev->of_node->name; + init.ops = &hsdk_pll_ops; + parent_name = of_clk_get_parent_name(dev->of_node, 0); + init.parent_names = &parent_name; + num_parents = of_clk_get_parent_count(dev->of_node); + if (num_parents == 0 || num_parents > CGU_PLL_SOURCE_MAX) { + dev_err(dev, "wrong clock parents number: %u\n", num_parents); + return -EINVAL; + } + init.num_parents = num_parents; + + pll_clk->hw.init = &init; + pll_clk->dev = dev; + pll_clk->pll_devdata = of_device_get_match_data(dev); + + if (!pll_clk->pll_devdata) { + dev_err(dev, "No OF match data provided\n"); + return -EINVAL; + } + + ret = devm_clk_hw_register(dev, &pll_clk->hw); + if (ret) { + dev_err(dev, "failed to register %s clock\n", init.name); + return ret; + } + + return of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get, + &pll_clk->hw); +} + +static int hsdk_pll_clk_remove(struct platform_device *pdev) +{ + of_clk_del_provider(pdev->dev.of_node); + return 0; +} + +static void __init of_hsdk_pll_clk_setup(struct device_node *node) +{ + int ret; + const char *parent_name; + unsigned int num_parents; + struct hsdk_pll_clk *pll_clk; + struct clk_init_data init = { }; + + pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL); + if (!pll_clk) + return; + + pll_clk->regs = of_iomap(node, 0); + if (!pll_clk->regs) { + pr_err("failed to map pll registers\n"); + goto err_free_pll_clk; + } + + pll_clk->spec_regs = of_iomap(node, 1); + if (!pll_clk->spec_regs) { + pr_err("failed to map pll registers\n"); + goto err_unmap_comm_regs; + } + + init.name = node->name; + init.ops = &hsdk_pll_ops; + parent_name = of_clk_get_parent_name(node, 0); + init.parent_names = &parent_name; + num_parents = of_clk_get_parent_count(node); + if (num_parents > CGU_PLL_SOURCE_MAX) { + pr_err("too much clock parents: %u\n", num_parents); + goto err_unmap_spec_regs; + } + init.num_parents = num_parents; + + pll_clk->hw.init = &init; + pll_clk->pll_devdata = &core_pll_devdata; + + ret = clk_hw_register(NULL, &pll_clk->hw); + if (ret) { + pr_err("failed to register %pOFn clock\n", node); + goto err_unmap_spec_regs; + } + + ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll_clk->hw); + if (ret) { + pr_err("failed to add hw provider for %pOFn clock\n", node); + goto err_unmap_spec_regs; + } + + return; + +err_unmap_spec_regs: + iounmap(pll_clk->spec_regs); +err_unmap_comm_regs: + iounmap(pll_clk->regs); +err_free_pll_clk: + kfree(pll_clk); +} + +/* Core PLL needed early for ARC cpus timers */ +CLK_OF_DECLARE(hsdk_pll_clock, "snps,hsdk-core-pll-clock", +of_hsdk_pll_clk_setup); + +static const struct of_device_id hsdk_pll_clk_id[] = { + { .compatible = "snps,hsdk-gp-pll-clock", .data = &sdt_pll_devdata}, + { .compatible = "snps,hsdk-hdmi-pll-clock", .data = &hdmi_pll_devdata}, + { } +}; + +static struct platform_driver hsdk_pll_clk_driver = { + .driver = { + .name = "hsdk-gp-pll-clock", + .of_match_table = hsdk_pll_clk_id, + }, + .probe = hsdk_pll_clk_probe, + .remove = hsdk_pll_clk_remove, +}; +builtin_platform_driver(hsdk_pll_clk_driver); |