1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Freescale SAI BCLK as a generic clock driver 4 * 5 * Copyright 2020 Michael Walle <michael@walle.cc> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/platform_device.h> 10 #include <linux/clk-provider.h> 11 #include <linux/err.h> 12 #include <linux/of.h> 13 #include <linux/of_address.h> 14 #include <linux/slab.h> 15 16 #define I2S_CSR 0x00 17 #define I2S_CR2 0x08 18 #define CSR_BCE_BIT 28 19 #define CR2_BCD BIT(24) 20 #define CR2_DIV_SHIFT 0 21 #define CR2_DIV_WIDTH 8 22 23 struct fsl_sai_clk { 24 struct clk_divider div; 25 struct clk_gate gate; 26 spinlock_t lock; 27 }; 28 29 static int fsl_sai_clk_probe(struct platform_device *pdev) 30 { 31 struct device *dev = &pdev->dev; 32 struct fsl_sai_clk *sai_clk; 33 struct clk_parent_data pdata = { .index = 0 }; 34 void __iomem *base; 35 struct clk_hw *hw; 36 struct resource *res; 37 38 sai_clk = devm_kzalloc(dev, sizeof(*sai_clk), GFP_KERNEL); 39 if (!sai_clk) 40 return -ENOMEM; 41 42 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 43 base = devm_ioremap_resource(dev, res); 44 if (IS_ERR(base)) 45 return PTR_ERR(base); 46 47 spin_lock_init(&sai_clk->lock); 48 49 sai_clk->gate.reg = base + I2S_CSR; 50 sai_clk->gate.bit_idx = CSR_BCE_BIT; 51 sai_clk->gate.lock = &sai_clk->lock; 52 53 sai_clk->div.reg = base + I2S_CR2; 54 sai_clk->div.shift = CR2_DIV_SHIFT; 55 sai_clk->div.width = CR2_DIV_WIDTH; 56 sai_clk->div.lock = &sai_clk->lock; 57 58 /* set clock direction, we are the BCLK master */ 59 writel(CR2_BCD, base + I2S_CR2); 60 61 hw = clk_hw_register_composite_pdata(dev, dev->of_node->name, 62 &pdata, 1, NULL, NULL, 63 &sai_clk->div.hw, 64 &clk_divider_ops, 65 &sai_clk->gate.hw, 66 &clk_gate_ops, 67 CLK_SET_RATE_GATE); 68 if (IS_ERR(hw)) 69 return PTR_ERR(hw); 70 71 return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw); 72 } 73 74 static const struct of_device_id of_fsl_sai_clk_ids[] = { 75 { .compatible = "fsl,vf610-sai-clock" }, 76 { } 77 }; 78 MODULE_DEVICE_TABLE(of, of_fsl_sai_clk_ids); 79 80 static struct platform_driver fsl_sai_clk_driver = { 81 .probe = fsl_sai_clk_probe, 82 .driver = { 83 .name = "fsl-sai-clk", 84 .of_match_table = of_fsl_sai_clk_ids, 85 }, 86 }; 87 module_platform_driver(fsl_sai_clk_driver); 88 89 MODULE_DESCRIPTION("Freescale SAI bitclock-as-a-clock driver"); 90 MODULE_AUTHOR("Michael Walle <michael@walle.cc>"); 91 MODULE_LICENSE("GPL"); 92 MODULE_ALIAS("platform:fsl-sai-clk"); 93