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 return PTR_ERR_OR_ZERO(tcon->regs); 61 } 62 63 struct fsl_tcon *fsl_tcon_init(struct device *dev) 64 { 65 struct fsl_tcon *tcon; 66 struct device_node *np; 67 int ret; 68 69 /* TCON node is not mandatory, some devices do not provide TCON */ 70 np = of_parse_phandle(dev->of_node, "fsl,tcon", 0); 71 if (!np) 72 return NULL; 73 74 tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL); 75 if (!tcon) 76 goto err_node_put; 77 78 ret = fsl_tcon_init_regmap(dev, tcon, np); 79 if (ret) { 80 dev_err(dev, "Couldn't create the TCON regmap\n"); 81 goto err_node_put; 82 } 83 84 tcon->ipg_clk = of_clk_get_by_name(np, "ipg"); 85 if (IS_ERR(tcon->ipg_clk)) { 86 dev_err(dev, "Couldn't get the TCON bus clock\n"); 87 goto err_node_put; 88 } 89 90 ret = clk_prepare_enable(tcon->ipg_clk); 91 if (ret) { 92 dev_err(dev, "Couldn't enable the TCON clock\n"); 93 goto err_node_put; 94 } 95 96 of_node_put(np); 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 } 111 112