| /* |
| * Clock implementation for VIA/Wondermedia SoC's |
| * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz> |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #include <linux/io.h> |
| #include <linux/of.h> |
| #include <linux/slab.h> |
| #include <linux/bitops.h> |
| #include <linux/clkdev.h> |
| #include <linux/clk-provider.h> |
| |
| /* All clocks share the same lock as none can be changed concurrently */ |
| static DEFINE_SPINLOCK(_lock); |
| |
| struct clk_device { |
| struct clk_hw hw; |
| void __iomem *div_reg; |
| unsigned int div_mask; |
| void __iomem *en_reg; |
| int en_bit; |
| spinlock_t *lock; |
| }; |
| |
| /* |
| * Add new PLL_TYPE_x definitions here as required. Use the first known model |
| * to support the new type as the name. |
| * Add case statements to vtwm_pll_recalc_rate(), vtwm_pll_round_round() and |
| * vtwm_pll_set_rate() to handle the new PLL_TYPE_x |
| */ |
| |
| #define PLL_TYPE_VT8500 0 |
| #define PLL_TYPE_WM8650 1 |
| #define PLL_TYPE_WM8750 2 |
| |
| struct clk_pll { |
| struct clk_hw hw; |
| void __iomem *reg; |
| spinlock_t *lock; |
| int type; |
| }; |
| |
| static void __iomem *pmc_base; |
| |
| #define to_clk_device(_hw) container_of(_hw, struct clk_device, hw) |
| |
| #define VT8500_PMC_BUSY_MASK 0x18 |
| |
| static void vt8500_pmc_wait_busy(void) |
| { |
| while (readl(pmc_base) & VT8500_PMC_BUSY_MASK) |
| cpu_relax(); |
| } |
| |
| static int vt8500_dclk_enable(struct clk_hw *hw) |
| { |
| struct clk_device *cdev = to_clk_device(hw); |
| u32 en_val; |
| unsigned long flags = 0; |
| |
| spin_lock_irqsave(cdev->lock, flags); |
| |
| en_val = readl(cdev->en_reg); |
| en_val |= BIT(cdev->en_bit); |
| writel(en_val, cdev->en_reg); |
| |
| spin_unlock_irqrestore(cdev->lock, flags); |
| return 0; |
| } |
| |
| static void vt8500_dclk_disable(struct clk_hw *hw) |
| { |
| struct clk_device *cdev = to_clk_device(hw); |
| u32 en_val; |
| unsigned long flags = 0; |
| |
| spin_lock_irqsave(cdev->lock, flags); |
| |
| en_val = readl(cdev->en_reg); |
| en_val &= ~BIT(cdev->en_bit); |
| writel(en_val, cdev->en_reg); |
| |
| spin_unlock_irqrestore(cdev->lock, flags); |
| } |
| |
| static int vt8500_dclk_is_enabled(struct clk_hw *hw) |
| { |
| struct clk_device *cdev = to_clk_device(hw); |
| u32 en_val = (readl(cdev->en_reg) & BIT(cdev->en_bit)); |
| |
| return en_val ? 1 : 0; |
| } |
| |
| static unsigned long vt8500_dclk_recalc_rate(struct clk_hw *hw, |
| unsigned long parent_rate) |
| { |
| struct clk_device *cdev = to_clk_device(hw); |
| u32 div = readl(cdev->div_reg) & cdev->div_mask; |
| |
| /* Special case for SDMMC devices */ |
| if ((cdev->div_mask == 0x3F) && (div & BIT(5))) |
| div = 64 * (div & 0x1f); |
| |
| /* div == 0 is actually the highest divisor */ |
| if (div == 0) |
| div = (cdev->div_mask + 1); |
| |
| return parent_rate / div; |
| } |
| |
| static long vt8500_dclk_round_rate(struct clk_hw *hw, unsigned long rate, |
| unsigned long *prate) |
| { |
| struct clk_device *cdev = to_clk_device(hw); |
| u32 divisor; |
| |
| if (rate == 0) |
| return 0; |
| |
| divisor = *prate / rate; |
| |
| /* If prate / rate would be decimal, incr the divisor */ |
| if (rate * divisor < *prate) |
| divisor++; |
| |
| /* |
| * If this is a request for SDMMC we have to adjust the divisor |
| * when >31 to use the fixed predivisor |
| */ |
| if ((cdev->div_mask == 0x3F) && (divisor > 31)) { |
| divisor = 64 * ((divisor / 64) + 1); |
| } |
| |
| return *prate / divisor; |
| } |
| |
| static int vt8500_dclk_set_rate(struct clk_hw *hw, unsigned long rate, |
| unsigned long parent_rate) |
| { |
| struct clk_device *cdev = to_clk_device(hw); |
| u32 divisor; |
| unsigned long flags = 0; |
| |
| if (rate == 0) |
| return 0; |
| |
| divisor = parent_rate / rate; |
| |
| /* If prate / rate would be decimal, incr the divisor */ |
| if (rate * divisor < *prate) |
| divisor++; |
| |
| if (divisor == cdev->div_mask + 1) |
| divisor = 0; |
| |
| /* SDMMC mask may need to be corrected before testing if its valid */ |
| if ((cdev->div_mask == 0x3F) && (divisor > 31)) { |
| /* |
| * Bit 5 is a fixed /64 predivisor. If the requested divisor |
| * is >31 then correct for the fixed divisor being required. |
| */ |
| divisor = 0x20 + (divisor / 64); |
| } |
| |
| if (divisor > cdev->div_mask) { |
| pr_err("%s: invalid divisor for clock\n", __func__); |
| return -EINVAL; |
| } |
| |
| spin_lock_irqsave(cdev->lock, flags); |
| |
| vt8500_pmc_wait_busy(); |
| writel(divisor, cdev->div_reg); |
| vt8500_pmc_wait_busy(); |
| |
| spin_lock_irqsave(cdev->lock, flags); |
| |
| return 0; |
| } |
| |
| |
| static const struct clk_ops vt8500_gated_clk_ops = { |
| .enable = vt8500_dclk_enable, |
| .disable = vt8500_dclk_disable, |
| .is_enabled = vt8500_dclk_is_enabled, |
| }; |
| |
| static const struct clk_ops vt8500_divisor_clk_ops = { |
| .round_rate = vt8500_dclk_round_rate, |
| .set_rate = vt8500_dclk_set_rate, |
| .recalc_rate = vt8500_dclk_recalc_rate, |
| }; |
| |
| static const struct clk_ops vt8500_gated_divisor_clk_ops = { |
| .enable = vt8500_dclk_enable, |
| .disable = vt8500_dclk_disable, |
| .is_enabled = vt8500_dclk_is_enabled, |
| .round_rate = vt8500_dclk_round_rate, |
| .set_rate = vt8500_dclk_set_rate, |
| .recalc_rate = vt8500_dclk_recalc_rate, |
| }; |
| |
| #define CLK_INIT_GATED BIT(0) |
| #define CLK_INIT_DIVISOR BIT(1) |
| #define CLK_INIT_GATED_DIVISOR (CLK_INIT_DIVISOR | CLK_INIT_GATED) |
| |
| static __init void vtwm_device_clk_init(struct device_node *node) |
| { |
| u32 en_reg, div_reg; |
| struct clk *clk; |
| struct clk_device *dev_clk; |
| const char *clk_name = node->name; |
| const char *parent_name; |
| struct clk_init_data init; |
| int rc; |
| int clk_init_flags = 0; |
| |
| dev_clk = kzalloc(sizeof(*dev_clk), GFP_KERNEL); |
| if (WARN_ON(!dev_clk)) |
| return; |
| |
| dev_clk->lock = &_lock; |
| |
| rc = of_property_read_u32(node, "enable-reg", &en_reg); |
| if (!rc) { |
| dev_clk->en_reg = pmc_base + en_reg; |
| rc = of_property_read_u32(node, "enable-bit", &dev_clk->en_bit); |
| if (rc) { |
| pr_err("%s: enable-bit property required for gated clock\n", |
| __func__); |
| return; |
| } |
| clk_init_flags |= CLK_INIT_GATED; |
| } |
| |
| rc = of_property_read_u32(node, "divisor-reg", &div_reg); |
| if (!rc) { |
| dev_clk->div_reg = pmc_base + div_reg; |
| /* |
| * use 0x1f as the default mask since it covers |
| * almost all the clocks and reduces dts properties |
| */ |
| dev_clk->div_mask = 0x1f; |
| |
| of_property_read_u32(node, "divisor-mask", &dev_clk->div_mask); |
| clk_init_flags |= CLK_INIT_DIVISOR; |
| } |
| |
| of_property_read_string(node, "clock-output-names", &clk_name); |
| |
| switch (clk_init_flags) { |
| case CLK_INIT_GATED: |
| init.ops = &vt8500_gated_clk_ops; |
| break; |
| case CLK_INIT_DIVISOR: |
| init.ops = &vt8500_divisor_clk_ops; |
| break; |
| case CLK_INIT_GATED_DIVISOR: |
| init.ops = &vt8500_gated_divisor_clk_ops; |
| break; |
| default: |
| pr_err("%s: Invalid clock description in device tree\n", |
| __func__); |
| kfree(dev_clk); |
| return; |
| } |
| |
| init.name = clk_name; |
| init.flags = 0; |
| parent_name = of_clk_get_parent_name(node, 0); |
| init.parent_names = &parent_name; |
| init.num_parents = 1; |
| |
| dev_clk->hw.init = &init; |
| |
| clk = clk_register(NULL, &dev_clk->hw); |
| if (WARN_ON(IS_ERR(clk))) { |
| kfree(dev_clk); |
| return; |
| } |
| rc = of_clk_add_provider(node, of_clk_src_simple_get, clk); |
| clk_register_clkdev(clk, clk_name, NULL); |
| } |
| |
| |
| /* PLL clock related functions */ |
| |
| #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw) |
| |
| /* Helper macros for PLL_VT8500 */ |
| #define VT8500_PLL_MUL(x) ((x & 0x1F) << 1) |
| #define VT8500_PLL_DIV(x) ((x & 0x100) ? 1 : 2) |
| |
| #define VT8500_BITS_TO_FREQ(r, m, d) \ |
| ((r / d) * m) |
| |
| #define VT8500_BITS_TO_VAL(m, d) \ |
| ((d == 2 ? 0 : 0x100) | ((m >> 1) & 0x1F)) |
| |
| /* Helper macros for PLL_WM8650 */ |
| #define WM8650_PLL_MUL(x) (x & 0x3FF) |
| #define WM8650_PLL_DIV(x) (((x >> 10) & 7) * (1 << ((x >> 13) & 3))) |
| |
| #define WM8650_BITS_TO_FREQ(r, m, d1, d2) \ |
| (r * m / (d1 * (1 << d2))) |
| |
| #define WM8650_BITS_TO_VAL(m, d1, d2) \ |
| ((d2 << 13) | (d1 << 10) | (m & 0x3FF)) |
| |
| /* Helper macros for PLL_WM8750 */ |
| #define WM8750_PLL_MUL(x) (((x >> 16) & 0xFF) + 1) |
| #define WM8750_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 7))) |
| |
| #define WM8750_BITS_TO_FREQ(r, m, d1, d2) \ |
| (r * (m+1) / ((d1+1) * (1 << d2))) |
| |
| #define WM8750_BITS_TO_VAL(f, m, d1, d2) \ |
| ((f << 24) | ((m - 1) << 16) | ((d1 - 1) << 8) | d2) |
| |
| |
| static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate, |
| u32 *multiplier, u32 *prediv) |
| { |
| unsigned long tclk; |
| |
| /* sanity check */ |
| if ((rate < parent_rate * 4) || (rate > parent_rate * 62)) { |
| pr_err("%s: requested rate out of range\n", __func__); |
| *multiplier = 0; |
| *prediv = 1; |
| return; |
| } |
| if (rate <= parent_rate * 31) |
| /* use the prediv to double the resolution */ |
| *prediv = 2; |
| else |
| *prediv = 1; |
| |
| *multiplier = rate / (parent_rate / *prediv); |
| tclk = (parent_rate / *prediv) * *multiplier; |
| |
| if (tclk != rate) |
| pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, |
| rate, tclk); |
| } |
| |
| static void wm8650_find_pll_bits(unsigned long rate, unsigned long parent_rate, |
| u32 *multiplier, u32 *divisor1, u32 *divisor2) |
| { |
| u32 mul, div1, div2; |
| u32 best_mul, best_div1, best_div2; |
| unsigned long tclk, rate_err, best_err; |
| |
| best_err = (unsigned long)-1; |
| |
| /* Find the closest match (lower or equal to requested) */ |
| for (div1 = 5; div1 >= 3; div1--) |
| for (div2 = 3; div2 >= 0; div2--) |
| for (mul = 3; mul <= 1023; mul++) { |
| tclk = parent_rate * mul / (div1 * (1 << div2)); |
| if (tclk > rate) |
| continue; |
| /* error will always be +ve */ |
| rate_err = rate - tclk; |
| if (rate_err == 0) { |
| *multiplier = mul; |
| *divisor1 = div1; |
| *divisor2 = div2; |
| return; |
| } |
| |
| if (rate_err < best_err) { |
| best_err = rate_err; |
| best_mul = mul; |
| best_div1 = div1; |
| best_div2 = div2; |
| } |
| } |
| |
| /* if we got here, it wasn't an exact match */ |
| pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate, |
| rate - best_err); |
| *multiplier = best_mul; |
| *divisor1 = best_div1; |
| *divisor2 = best_div2; |
| } |
| |
| static u32 wm8750_get_filter(u32 parent_rate, u32 divisor1) |
| { |
| /* calculate frequency (MHz) after pre-divisor */ |
| u32 freq = (parent_rate / 1000000) / (divisor1 + 1); |
| |
| if ((freq < 10) || (freq > 200)) |
| pr_warn("%s: PLL recommended input frequency 10..200Mhz (requested %d Mhz)\n", |
| __func__, freq); |
| |
| if (freq >= 166) |
| return 7; |
| else if (freq >= 104) |
| return 6; |
| else if (freq >= 65) |
| return 5; |
| else if (freq >= 42) |
| return 4; |
| else if (freq >= 26) |
| return 3; |
| else if (freq >= 16) |
| return 2; |
| else if (freq >= 10) |
| return 1; |
| |
| return 0; |
| } |
| |
| static void wm8750_find_pll_bits(unsigned long rate, unsigned long parent_rate, |
| u32 *filter, u32 *multiplier, u32 *divisor1, u32 *divisor2) |
| { |
| u32 mul, div1, div2; |
| u32 best_mul, best_div1, best_div2; |
| unsigned long tclk, rate_err, best_err; |
| |
| best_err = (unsigned long)-1; |
| |
| /* Find the closest match (lower or equal to requested) */ |
| for (div1 = 1; div1 >= 0; div1--) |
| for (div2 = 7; div2 >= 0; div2--) |
| for (mul = 0; mul <= 255; mul++) { |
| tclk = parent_rate * (mul + 1) / ((div1 + 1) * (1 << div2)); |
| if (tclk > rate) |
| continue; |
| /* error will always be +ve */ |
| rate_err = rate - tclk; |
| if (rate_err == 0) { |
| *filter = wm8750_get_filter(parent_rate, div1); |
| *multiplier = mul; |
| *divisor1 = div1; |
| *divisor2 = div2; |
| return; |
| } |
| |
| if (rate_err < best_err) { |
| best_err = rate_err; |
| best_mul = mul; |
| best_div1 = div1; |
| best_div2 = div2; |
| } |
| } |
| |
| /* if we got here, it wasn't an exact match */ |
| pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate, |
| rate - best_err); |
| |
| *filter = wm8750_get_filter(parent_rate, best_div1); |
| *multiplier = best_mul; |
| *divisor1 = best_div1; |
| *divisor2 = best_div2; |
| } |
| |
| static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate, |
| unsigned long parent_rate) |
| { |
| struct clk_pll *pll = to_clk_pll(hw); |
| u32 filter, mul, div1, div2; |
| u32 pll_val; |
| unsigned long flags = 0; |
| |
| /* sanity check */ |
| |
| switch (pll->type) { |
| case PLL_TYPE_VT8500: |
| vt8500_find_pll_bits(rate, parent_rate, &mul, &div1); |
| pll_val = VT8500_BITS_TO_VAL(mul, div1); |
| break; |
| case PLL_TYPE_WM8650: |
| wm8650_find_pll_bits(rate, parent_rate, &mul, &div1, &div2); |
| pll_val = WM8650_BITS_TO_VAL(mul, div1, div2); |
| break; |
| case PLL_TYPE_WM8750: |
| wm8750_find_pll_bits(rate, parent_rate, &filter, &mul, &div1, &div2); |
| pll_val = WM8750_BITS_TO_VAL(filter, mul, div1, div2); |
| default: |
| pr_err("%s: invalid pll type\n", __func__); |
| return 0; |
| } |
| |
| spin_lock_irqsave(pll->lock, flags); |
| |
| vt8500_pmc_wait_busy(); |
| writel(pll_val, pll->reg); |
| vt8500_pmc_wait_busy(); |
| |
| spin_unlock_irqrestore(pll->lock, flags); |
| |
| return 0; |
| } |
| |
| static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate, |
| unsigned long *prate) |
| { |
| struct clk_pll *pll = to_clk_pll(hw); |
| u32 filter, mul, div1, div2; |
| long round_rate; |
| |
| switch (pll->type) { |
| case PLL_TYPE_VT8500: |
| vt8500_find_pll_bits(rate, *prate, &mul, &div1); |
| round_rate = VT8500_BITS_TO_FREQ(*prate, mul, div1); |
| break; |
| case PLL_TYPE_WM8650: |
| wm8650_find_pll_bits(rate, *prate, &mul, &div1, &div2); |
| round_rate = WM8650_BITS_TO_FREQ(*prate, mul, div1, div2); |
| break; |
| case PLL_TYPE_WM8750: |
| wm8750_find_pll_bits(rate, *prate, &filter, &mul, &div1, &div2); |
| round_rate = WM8750_BITS_TO_FREQ(*prate, mul, div1, div2); |
| default: |
| round_rate = 0; |
| } |
| |
| return round_rate; |
| } |
| |
| static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw, |
| unsigned long parent_rate) |
| { |
| struct clk_pll *pll = to_clk_pll(hw); |
| u32 pll_val = readl(pll->reg); |
| unsigned long pll_freq; |
| |
| switch (pll->type) { |
| case PLL_TYPE_VT8500: |
| pll_freq = parent_rate * VT8500_PLL_MUL(pll_val); |
| pll_freq /= VT8500_PLL_DIV(pll_val); |
| break; |
| case PLL_TYPE_WM8650: |
| pll_freq = parent_rate * WM8650_PLL_MUL(pll_val); |
| pll_freq /= WM8650_PLL_DIV(pll_val); |
| break; |
| case PLL_TYPE_WM8750: |
| pll_freq = parent_rate * WM8750_PLL_MUL(pll_val); |
| pll_freq /= WM8750_PLL_DIV(pll_val); |
| break; |
| default: |
| pll_freq = 0; |
| } |
| |
| return pll_freq; |
| } |
| |
| const struct clk_ops vtwm_pll_ops = { |
| .round_rate = vtwm_pll_round_rate, |
| .set_rate = vtwm_pll_set_rate, |
| .recalc_rate = vtwm_pll_recalc_rate, |
| }; |
| |
| static __init void vtwm_pll_clk_init(struct device_node *node, int pll_type) |
| { |
| u32 reg; |
| struct clk *clk; |
| struct clk_pll *pll_clk; |
| const char *clk_name = node->name; |
| const char *parent_name; |
| struct clk_init_data init; |
| int rc; |
| |
| rc = of_property_read_u32(node, "reg", ®); |
| if (WARN_ON(rc)) |
| return; |
| |
| pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL); |
| if (WARN_ON(!pll_clk)) |
| return; |
| |
| pll_clk->reg = pmc_base + reg; |
| pll_clk->lock = &_lock; |
| pll_clk->type = pll_type; |
| |
| of_property_read_string(node, "clock-output-names", &clk_name); |
| |
| init.name = clk_name; |
| init.ops = &vtwm_pll_ops; |
| init.flags = 0; |
| parent_name = of_clk_get_parent_name(node, 0); |
| init.parent_names = &parent_name; |
| init.num_parents = 1; |
| |
| pll_clk->hw.init = &init; |
| |
| clk = clk_register(NULL, &pll_clk->hw); |
| if (WARN_ON(IS_ERR(clk))) { |
| kfree(pll_clk); |
| return; |
| } |
| rc = of_clk_add_provider(node, of_clk_src_simple_get, clk); |
| clk_register_clkdev(clk, clk_name, NULL); |
| } |
| |
| |
| /* Wrappers for initialization functions */ |
| |
| static void __init vt8500_pll_init(struct device_node *node) |
| { |
| vtwm_pll_clk_init(node, PLL_TYPE_VT8500); |
| } |
| |
| static void __init wm8650_pll_init(struct device_node *node) |
| { |
| vtwm_pll_clk_init(node, PLL_TYPE_WM8650); |
| } |
| |
| static void __init wm8750_pll_init(struct device_node *node) |
| { |
| vtwm_pll_clk_init(node, PLL_TYPE_WM8750); |
| } |
| |
| static const __initconst struct of_device_id clk_match[] = { |
| { .compatible = "fixed-clock", .data = of_fixed_clk_setup, }, |
| { .compatible = "via,vt8500-pll-clock", .data = vt8500_pll_init, }, |
| { .compatible = "wm,wm8650-pll-clock", .data = wm8650_pll_init, }, |
| { .compatible = "wm,wm8750-pll-clock", .data = wm8750_pll_init, }, |
| { .compatible = "via,vt8500-device-clock", |
| .data = vtwm_device_clk_init, }, |
| { /* sentinel */ } |
| }; |
| |
| void __init vtwm_clk_init(void __iomem *base) |
| { |
| if (!base) |
| return; |
| |
| pmc_base = base; |
| |
| of_clk_init(clk_match); |
| } |