| /* |
| * Intel Atom platform clocks driver for BayTrail and CherryTrail SoCs |
| * |
| * Copyright (C) 2016, Intel Corporation |
| * Author: Irina Tirdea <irina.tirdea@intel.com> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms and conditions of the GNU General Public License, |
| * version 2, as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope 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/clk-provider.h> |
| #include <linux/clkdev.h> |
| #include <linux/err.h> |
| #include <linux/io.h> |
| #include <linux/platform_data/x86/clk-pmc-atom.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| |
| #define PLT_CLK_NAME_BASE "pmc_plt_clk" |
| |
| #define PMC_CLK_CTL_OFFSET 0x60 |
| #define PMC_CLK_CTL_SIZE 4 |
| #define PMC_CLK_NUM 6 |
| #define PMC_CLK_CTL_GATED_ON_D3 0x0 |
| #define PMC_CLK_CTL_FORCE_ON 0x1 |
| #define PMC_CLK_CTL_FORCE_OFF 0x2 |
| #define PMC_CLK_CTL_RESERVED 0x3 |
| #define PMC_MASK_CLK_CTL GENMASK(1, 0) |
| #define PMC_MASK_CLK_FREQ BIT(2) |
| #define PMC_CLK_FREQ_XTAL (0 << 2) /* 25 MHz */ |
| #define PMC_CLK_FREQ_PLL (1 << 2) /* 19.2 MHz */ |
| |
| struct clk_plt_fixed { |
| struct clk_hw *clk; |
| struct clk_lookup *lookup; |
| }; |
| |
| struct clk_plt { |
| struct clk_hw hw; |
| void __iomem *reg; |
| struct clk_lookup *lookup; |
| /* protect access to PMC registers */ |
| spinlock_t lock; |
| }; |
| |
| #define to_clk_plt(_hw) container_of(_hw, struct clk_plt, hw) |
| |
| struct clk_plt_data { |
| struct clk_plt_fixed **parents; |
| u8 nparents; |
| struct clk_plt *clks[PMC_CLK_NUM]; |
| struct clk_lookup *mclk_lookup; |
| struct clk_lookup *ether_clk_lookup; |
| }; |
| |
| /* Return an index in parent table */ |
| static inline int plt_reg_to_parent(int reg) |
| { |
| switch (reg & PMC_MASK_CLK_FREQ) { |
| default: |
| case PMC_CLK_FREQ_XTAL: |
| return 0; |
| case PMC_CLK_FREQ_PLL: |
| return 1; |
| } |
| } |
| |
| /* Return clk index of parent */ |
| static inline int plt_parent_to_reg(int index) |
| { |
| switch (index) { |
| default: |
| case 0: |
| return PMC_CLK_FREQ_XTAL; |
| case 1: |
| return PMC_CLK_FREQ_PLL; |
| } |
| } |
| |
| /* Abstract status in simpler enabled/disabled value */ |
| static inline int plt_reg_to_enabled(int reg) |
| { |
| switch (reg & PMC_MASK_CLK_CTL) { |
| case PMC_CLK_CTL_GATED_ON_D3: |
| case PMC_CLK_CTL_FORCE_ON: |
| return 1; /* enabled */ |
| case PMC_CLK_CTL_FORCE_OFF: |
| case PMC_CLK_CTL_RESERVED: |
| default: |
| return 0; /* disabled */ |
| } |
| } |
| |
| static void plt_clk_reg_update(struct clk_plt *clk, u32 mask, u32 val) |
| { |
| u32 tmp; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&clk->lock, flags); |
| |
| tmp = readl(clk->reg); |
| tmp = (tmp & ~mask) | (val & mask); |
| writel(tmp, clk->reg); |
| |
| spin_unlock_irqrestore(&clk->lock, flags); |
| } |
| |
| static int plt_clk_set_parent(struct clk_hw *hw, u8 index) |
| { |
| struct clk_plt *clk = to_clk_plt(hw); |
| |
| plt_clk_reg_update(clk, PMC_MASK_CLK_FREQ, plt_parent_to_reg(index)); |
| |
| return 0; |
| } |
| |
| static u8 plt_clk_get_parent(struct clk_hw *hw) |
| { |
| struct clk_plt *clk = to_clk_plt(hw); |
| u32 value; |
| |
| value = readl(clk->reg); |
| |
| return plt_reg_to_parent(value); |
| } |
| |
| static int plt_clk_enable(struct clk_hw *hw) |
| { |
| struct clk_plt *clk = to_clk_plt(hw); |
| |
| plt_clk_reg_update(clk, PMC_MASK_CLK_CTL, PMC_CLK_CTL_FORCE_ON); |
| |
| return 0; |
| } |
| |
| static void plt_clk_disable(struct clk_hw *hw) |
| { |
| struct clk_plt *clk = to_clk_plt(hw); |
| |
| plt_clk_reg_update(clk, PMC_MASK_CLK_CTL, PMC_CLK_CTL_FORCE_OFF); |
| } |
| |
| static int plt_clk_is_enabled(struct clk_hw *hw) |
| { |
| struct clk_plt *clk = to_clk_plt(hw); |
| u32 value; |
| |
| value = readl(clk->reg); |
| |
| return plt_reg_to_enabled(value); |
| } |
| |
| static const struct clk_ops plt_clk_ops = { |
| .enable = plt_clk_enable, |
| .disable = plt_clk_disable, |
| .is_enabled = plt_clk_is_enabled, |
| .get_parent = plt_clk_get_parent, |
| .set_parent = plt_clk_set_parent, |
| .determine_rate = __clk_mux_determine_rate, |
| }; |
| |
| static struct clk_plt *plt_clk_register(struct platform_device *pdev, int id, |
| const struct pmc_clk_data *pmc_data, |
| const char **parent_names, |
| int num_parents) |
| { |
| struct clk_plt *pclk; |
| struct clk_init_data init; |
| int ret; |
| |
| pclk = devm_kzalloc(&pdev->dev, sizeof(*pclk), GFP_KERNEL); |
| if (!pclk) |
| return ERR_PTR(-ENOMEM); |
| |
| init.name = kasprintf(GFP_KERNEL, "%s_%d", PLT_CLK_NAME_BASE, id); |
| init.ops = &plt_clk_ops; |
| init.flags = 0; |
| init.parent_names = parent_names; |
| init.num_parents = num_parents; |
| |
| pclk->hw.init = &init; |
| pclk->reg = pmc_data->base + PMC_CLK_CTL_OFFSET + id * PMC_CLK_CTL_SIZE; |
| spin_lock_init(&pclk->lock); |
| |
| /* |
| * On some systems, the pmc_plt_clocks already enabled by the |
| * firmware are being marked as critical to avoid them being |
| * gated by the clock framework. |
| */ |
| if (pmc_data->critical && plt_clk_is_enabled(&pclk->hw)) |
| init.flags |= CLK_IS_CRITICAL; |
| |
| ret = devm_clk_hw_register(&pdev->dev, &pclk->hw); |
| if (ret) { |
| pclk = ERR_PTR(ret); |
| goto err_free_init; |
| } |
| |
| pclk->lookup = clkdev_hw_create(&pclk->hw, init.name, NULL); |
| if (!pclk->lookup) { |
| pclk = ERR_PTR(-ENOMEM); |
| goto err_free_init; |
| } |
| |
| err_free_init: |
| kfree(init.name); |
| return pclk; |
| } |
| |
| static void plt_clk_unregister(struct clk_plt *pclk) |
| { |
| clkdev_drop(pclk->lookup); |
| } |
| |
| static struct clk_plt_fixed *plt_clk_register_fixed_rate(struct platform_device *pdev, |
| const char *name, |
| const char *parent_name, |
| unsigned long fixed_rate) |
| { |
| struct clk_plt_fixed *pclk; |
| |
| pclk = devm_kzalloc(&pdev->dev, sizeof(*pclk), GFP_KERNEL); |
| if (!pclk) |
| return ERR_PTR(-ENOMEM); |
| |
| pclk->clk = clk_hw_register_fixed_rate(&pdev->dev, name, parent_name, |
| 0, fixed_rate); |
| if (IS_ERR(pclk->clk)) |
| return ERR_CAST(pclk->clk); |
| |
| pclk->lookup = clkdev_hw_create(pclk->clk, name, NULL); |
| if (!pclk->lookup) { |
| clk_hw_unregister_fixed_rate(pclk->clk); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| return pclk; |
| } |
| |
| static void plt_clk_unregister_fixed_rate(struct clk_plt_fixed *pclk) |
| { |
| clkdev_drop(pclk->lookup); |
| clk_hw_unregister_fixed_rate(pclk->clk); |
| } |
| |
| static void plt_clk_unregister_fixed_rate_loop(struct clk_plt_data *data, |
| unsigned int i) |
| { |
| while (i--) |
| plt_clk_unregister_fixed_rate(data->parents[i]); |
| } |
| |
| static void plt_clk_free_parent_names_loop(const char **parent_names, |
| unsigned int i) |
| { |
| while (i--) |
| kfree_const(parent_names[i]); |
| kfree(parent_names); |
| } |
| |
| static void plt_clk_unregister_loop(struct clk_plt_data *data, |
| unsigned int i) |
| { |
| while (i--) |
| plt_clk_unregister(data->clks[i]); |
| } |
| |
| static const char **plt_clk_register_parents(struct platform_device *pdev, |
| struct clk_plt_data *data, |
| const struct pmc_clk *clks) |
| { |
| const char **parent_names; |
| unsigned int i; |
| int err; |
| int nparents = 0; |
| |
| data->nparents = 0; |
| while (clks[nparents].name) |
| nparents++; |
| |
| data->parents = devm_kcalloc(&pdev->dev, nparents, |
| sizeof(*data->parents), GFP_KERNEL); |
| if (!data->parents) |
| return ERR_PTR(-ENOMEM); |
| |
| parent_names = kcalloc(nparents, sizeof(*parent_names), |
| GFP_KERNEL); |
| if (!parent_names) |
| return ERR_PTR(-ENOMEM); |
| |
| for (i = 0; i < nparents; i++) { |
| data->parents[i] = |
| plt_clk_register_fixed_rate(pdev, clks[i].name, |
| clks[i].parent_name, |
| clks[i].freq); |
| if (IS_ERR(data->parents[i])) { |
| err = PTR_ERR(data->parents[i]); |
| goto err_unreg; |
| } |
| parent_names[i] = kstrdup_const(clks[i].name, GFP_KERNEL); |
| } |
| |
| data->nparents = nparents; |
| return parent_names; |
| |
| err_unreg: |
| plt_clk_unregister_fixed_rate_loop(data, i); |
| plt_clk_free_parent_names_loop(parent_names, i); |
| return ERR_PTR(err); |
| } |
| |
| static void plt_clk_unregister_parents(struct clk_plt_data *data) |
| { |
| plt_clk_unregister_fixed_rate_loop(data, data->nparents); |
| } |
| |
| static int plt_clk_probe(struct platform_device *pdev) |
| { |
| const struct pmc_clk_data *pmc_data; |
| const char **parent_names; |
| struct clk_plt_data *data; |
| unsigned int i; |
| int err; |
| |
| pmc_data = dev_get_platdata(&pdev->dev); |
| if (!pmc_data || !pmc_data->clks) |
| return -EINVAL; |
| |
| data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| |
| parent_names = plt_clk_register_parents(pdev, data, pmc_data->clks); |
| if (IS_ERR(parent_names)) |
| return PTR_ERR(parent_names); |
| |
| for (i = 0; i < PMC_CLK_NUM; i++) { |
| data->clks[i] = plt_clk_register(pdev, i, pmc_data, |
| parent_names, data->nparents); |
| if (IS_ERR(data->clks[i])) { |
| err = PTR_ERR(data->clks[i]); |
| goto err_unreg_clk_plt; |
| } |
| } |
| data->mclk_lookup = clkdev_hw_create(&data->clks[3]->hw, "mclk", NULL); |
| if (!data->mclk_lookup) { |
| err = -ENOMEM; |
| goto err_unreg_clk_plt; |
| } |
| |
| data->ether_clk_lookup = clkdev_hw_create(&data->clks[4]->hw, |
| "ether_clk", NULL); |
| if (!data->ether_clk_lookup) { |
| err = -ENOMEM; |
| goto err_drop_mclk; |
| } |
| |
| plt_clk_free_parent_names_loop(parent_names, data->nparents); |
| |
| platform_set_drvdata(pdev, data); |
| return 0; |
| |
| err_drop_mclk: |
| clkdev_drop(data->mclk_lookup); |
| err_unreg_clk_plt: |
| plt_clk_unregister_loop(data, i); |
| plt_clk_unregister_parents(data); |
| plt_clk_free_parent_names_loop(parent_names, data->nparents); |
| return err; |
| } |
| |
| static int plt_clk_remove(struct platform_device *pdev) |
| { |
| struct clk_plt_data *data; |
| |
| data = platform_get_drvdata(pdev); |
| |
| clkdev_drop(data->ether_clk_lookup); |
| clkdev_drop(data->mclk_lookup); |
| plt_clk_unregister_loop(data, PMC_CLK_NUM); |
| plt_clk_unregister_parents(data); |
| return 0; |
| } |
| |
| static struct platform_driver plt_clk_driver = { |
| .driver = { |
| .name = "clk-pmc-atom", |
| }, |
| .probe = plt_clk_probe, |
| .remove = plt_clk_remove, |
| }; |
| builtin_platform_driver(plt_clk_driver); |