| Stefan Agner | fb127b7 | 2015-12-02 14:39:40 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2015 Toradex AG |
| 3 | * |
| 4 | * Stefan Agner <stefan@agner.ch> |
| 5 | * |
| 6 | * Freescale TCON device driver |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/clk.h> |
| 15 | #include <linux/io.h> |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/of_address.h> |
| 18 | #include <linux/platform_device.h> |
| 19 | #include <linux/regmap.h> |
| 20 | |
| 21 | #include "fsl_tcon.h" |
| 22 | |
| 23 | void fsl_tcon_bypass_disable(struct fsl_tcon *tcon) |
| 24 | { |
| 25 | regmap_update_bits(tcon->regs, FSL_TCON_CTRL1, |
| 26 | FSL_TCON_CTRL1_TCON_BYPASS, 0); |
| 27 | } |
| 28 | |
| 29 | void fsl_tcon_bypass_enable(struct fsl_tcon *tcon) |
| 30 | { |
| 31 | regmap_update_bits(tcon->regs, FSL_TCON_CTRL1, |
| 32 | FSL_TCON_CTRL1_TCON_BYPASS, |
| 33 | FSL_TCON_CTRL1_TCON_BYPASS); |
| 34 | } |
| 35 | |
| 36 | static struct regmap_config fsl_tcon_regmap_config = { |
| 37 | .reg_bits = 32, |
| 38 | .reg_stride = 4, |
| 39 | .val_bits = 32, |
| 40 | |
| 41 | .name = "tcon", |
| 42 | }; |
| 43 | |
| 44 | static int fsl_tcon_init_regmap(struct device *dev, |
| 45 | struct fsl_tcon *tcon, |
| 46 | struct device_node *np) |
| 47 | { |
| 48 | struct resource res; |
| 49 | void __iomem *regs; |
| 50 | |
| 51 | if (of_address_to_resource(np, 0, &res)) |
| 52 | return -EINVAL; |
| 53 | |
| 54 | regs = devm_ioremap_resource(dev, &res); |
| 55 | if (IS_ERR(regs)) |
| 56 | return PTR_ERR(regs); |
| 57 | |
| 58 | tcon->regs = devm_regmap_init_mmio(dev, regs, |
| 59 | &fsl_tcon_regmap_config); |
| 60 | if (IS_ERR(tcon->regs)) |
| 61 | return PTR_ERR(tcon->regs); |
| 62 | |
| 63 | return 0; |
| 64 | } |
| 65 | |
| 66 | struct fsl_tcon *fsl_tcon_init(struct device *dev) |
| 67 | { |
| 68 | struct fsl_tcon *tcon; |
| 69 | struct device_node *np; |
| 70 | int ret; |
| 71 | |
| 72 | /* TCON node is not mandatory, some devices do not provide TCON */ |
| 73 | np = of_parse_phandle(dev->of_node, "fsl,tcon", 0); |
| 74 | if (!np) |
| 75 | return NULL; |
| 76 | |
| 77 | tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL); |
| 78 | if (!tcon) { |
| 79 | ret = -ENOMEM; |
| 80 | goto err_node_put; |
| 81 | } |
| 82 | |
| 83 | ret = fsl_tcon_init_regmap(dev, tcon, np); |
| 84 | if (ret) { |
| 85 | dev_err(dev, "Couldn't create the TCON regmap\n"); |
| 86 | goto err_node_put; |
| 87 | } |
| 88 | |
| 89 | tcon->ipg_clk = of_clk_get_by_name(np, "ipg"); |
| 90 | if (IS_ERR(tcon->ipg_clk)) { |
| 91 | dev_err(dev, "Couldn't get the TCON bus clock\n"); |
| 92 | goto err_node_put; |
| 93 | } |
| 94 | |
| 95 | clk_prepare_enable(tcon->ipg_clk); |
| 96 | |
| 97 | dev_info(dev, "Using TCON in bypass mode\n"); |
| 98 | |
| 99 | return tcon; |
| 100 | |
| 101 | err_node_put: |
| 102 | of_node_put(np); |
| 103 | return NULL; |
| 104 | } |
| 105 | |
| 106 | void fsl_tcon_free(struct fsl_tcon *tcon) |
| 107 | { |
| 108 | clk_disable_unprepare(tcon->ipg_clk); |
| 109 | clk_put(tcon->ipg_clk); |
| 110 | } |
| 111 | |