1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2015 Toradex AG 4 * 5 * Stefan Agner <stefan@agner.ch> 6 * 7 * Freescale TCON device driver 8 */ 9 10 #include <linux/clk.h> 11 #include <linux/io.h> 12 #include <linux/mm.h> 13 #include <linux/of_address.h> 14 #include <linux/platform_device.h> 15 #include <linux/regmap.h> 16 17 #include "fsl_tcon.h" 18 19 void fsl_tcon_bypass_disable(struct fsl_tcon *tcon) 20 { 21 regmap_update_bits(tcon->regs, FSL_TCON_CTRL1, 22 FSL_TCON_CTRL1_TCON_BYPASS, 0); 23 } 24 25 void fsl_tcon_bypass_enable(struct fsl_tcon *tcon) 26 { 27 regmap_update_bits(tcon->regs, FSL_TCON_CTRL1, 28 FSL_TCON_CTRL1_TCON_BYPASS, 29 FSL_TCON_CTRL1_TCON_BYPASS); 30 } 31 32 static struct regmap_config fsl_tcon_regmap_config = { 33 .reg_bits = 32, 34 .reg_stride = 4, 35 .val_bits = 32, 36 37 .name = "tcon", 38 }; 39 40 static int fsl_tcon_init_regmap(struct device *dev, 41 struct fsl_tcon *tcon, 42 struct device_node *np) 43 { 44 struct resource res; 45 void __iomem *regs; 46 47 if (of_address_to_resource(np, 0, &res)) 48 return -EINVAL; 49 50 regs = devm_ioremap_resource(dev, &res); 51 if (IS_ERR(regs)) 52 return PTR_ERR(regs); 53 54 tcon->regs = devm_regmap_init_mmio(dev, regs, 55 &fsl_tcon_regmap_config); 56 return PTR_ERR_OR_ZERO(tcon->regs); 57 } 58 59 struct fsl_tcon *fsl_tcon_init(struct device *dev) 60 { 61 struct fsl_tcon *tcon; 62 struct device_node *np; 63 int ret; 64 65 /* TCON node is not mandatory, some devices do not provide TCON */ 66 np = of_parse_phandle(dev->of_node, "fsl,tcon", 0); 67 if (!np) 68 return NULL; 69 70 tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL); 71 if (!tcon) 72 goto err_node_put; 73 74 ret = fsl_tcon_init_regmap(dev, tcon, np); 75 if (ret) { 76 dev_err(dev, "Couldn't create the TCON regmap\n"); 77 goto err_node_put; 78 } 79 80 tcon->ipg_clk = of_clk_get_by_name(np, "ipg"); 81 if (IS_ERR(tcon->ipg_clk)) { 82 dev_err(dev, "Couldn't get the TCON bus clock\n"); 83 goto err_node_put; 84 } 85 86 ret = clk_prepare_enable(tcon->ipg_clk); 87 if (ret) { 88 dev_err(dev, "Couldn't enable the TCON clock\n"); 89 goto err_node_put; 90 } 91 92 of_node_put(np); 93 dev_info(dev, "Using TCON in bypass mode\n"); 94 95 return tcon; 96 97 err_node_put: 98 of_node_put(np); 99 return NULL; 100 } 101 102 void fsl_tcon_free(struct fsl_tcon *tcon) 103 { 104 clk_disable_unprepare(tcon->ipg_clk); 105 clk_put(tcon->ipg_clk); 106 } 107 108