diff options
Diffstat (limited to 'drivers/clk/clk-fsl-sai.c')
| -rw-r--r-- | drivers/clk/clk-fsl-sai.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/drivers/clk/clk-fsl-sai.c b/drivers/clk/clk-fsl-sai.c new file mode 100644 index 0000000000..cba45e0756 --- /dev/null +++ b/drivers/clk/clk-fsl-sai.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Freescale SAI BCLK as a generic clock driver + * + * Copyright 2020 Michael Walle <michael@walle.cc> + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/slab.h> + +#define I2S_CSR 0x00 +#define I2S_CR2 0x08 +#define CSR_BCE_BIT 28 +#define CR2_BCD BIT(24) +#define CR2_DIV_SHIFT 0 +#define CR2_DIV_WIDTH 8 + +struct fsl_sai_clk { + struct clk_divider div; + struct clk_gate gate; + spinlock_t lock; +}; + +static int fsl_sai_clk_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct fsl_sai_clk *sai_clk; + struct clk_parent_data pdata = { .index = 0 }; + void __iomem *base; + struct clk_hw *hw; + + sai_clk = devm_kzalloc(dev, sizeof(*sai_clk), GFP_KERNEL); + if (!sai_clk) + return -ENOMEM; + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return PTR_ERR(base); + + spin_lock_init(&sai_clk->lock); + + sai_clk->gate.reg = base + I2S_CSR; + sai_clk->gate.bit_idx = CSR_BCE_BIT; + sai_clk->gate.lock = &sai_clk->lock; + + sai_clk->div.reg = base + I2S_CR2; + sai_clk->div.shift = CR2_DIV_SHIFT; + sai_clk->div.width = CR2_DIV_WIDTH; + sai_clk->div.lock = &sai_clk->lock; + + /* set clock direction, we are the BCLK master */ + writel(CR2_BCD, base + I2S_CR2); + + hw = devm_clk_hw_register_composite_pdata(dev, dev->of_node->name, + &pdata, 1, NULL, NULL, + &sai_clk->div.hw, + &clk_divider_ops, + &sai_clk->gate.hw, + &clk_gate_ops, + CLK_SET_RATE_GATE); + if (IS_ERR(hw)) + return PTR_ERR(hw); + + return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw); +} + +static const struct of_device_id of_fsl_sai_clk_ids[] = { + { .compatible = "fsl,vf610-sai-clock" }, + { } +}; +MODULE_DEVICE_TABLE(of, of_fsl_sai_clk_ids); + +static struct platform_driver fsl_sai_clk_driver = { + .probe = fsl_sai_clk_probe, + .driver = { + .name = "fsl-sai-clk", + .of_match_table = of_fsl_sai_clk_ids, + }, +}; +module_platform_driver(fsl_sai_clk_driver); + +MODULE_DESCRIPTION("Freescale SAI bitclock-as-a-clock driver"); +MODULE_AUTHOR("Michael Walle <michael@walle.cc>"); +MODULE_ALIAS("platform:fsl-sai-clk"); |