1 // SPDX-License-Identifier: GPL-2.0
3  * Simple memory-mapped device MDIO MUX driver
11 #include <linux/mdio-mux.h>
26  * MDIO multiplexing switch function
28  * This function is called by the mdio-mux layer when it thinks the mdio bus
31  * 'current_child' is the current value of the mux register (masked via
32  * s->mask).
34  * 'desired_child' is the value of the 'reg' property of the target child MDIO
37  * The first time this function is called, current_child == -1.
39  * If current_child == desired_child, then the mux is already set to the
48 		void __iomem *p = ioremap(s->phys, s->iosize);  in mdio_mux_mmioreg_switch_fn()
50 			return -ENOMEM;  in mdio_mux_mmioreg_switch_fn()
52 		switch (s->iosize) {  in mdio_mux_mmioreg_switch_fn()
57 			y = (x & ~s->mask) | desired_child;  in mdio_mux_mmioreg_switch_fn()
59 				iowrite8((x & ~s->mask) | desired_child, p);  in mdio_mux_mmioreg_switch_fn()
60 				pr_debug("%s: %02x -> %02x\n", __func__, x, y);  in mdio_mux_mmioreg_switch_fn()
69 			y = (x & ~s->mask) | desired_child;  in mdio_mux_mmioreg_switch_fn()
71 				iowrite16((x & ~s->mask) | desired_child, p);  in mdio_mux_mmioreg_switch_fn()
72 				pr_debug("%s: %04x -> %04x\n", __func__, x, y);  in mdio_mux_mmioreg_switch_fn()
81 			y = (x & ~s->mask) | desired_child;  in mdio_mux_mmioreg_switch_fn()
83 				iowrite32((x & ~s->mask) | desired_child, p);  in mdio_mux_mmioreg_switch_fn()
84 				pr_debug("%s: %08x -> %08x\n", __func__, x, y);  in mdio_mux_mmioreg_switch_fn()
99 	struct device_node *np2, *np = pdev->dev.of_node;  in mdio_mux_mmioreg_probe()
105 	dev_dbg(&pdev->dev, "probing node %pOF\n", np);  in mdio_mux_mmioreg_probe()
107 	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);  in mdio_mux_mmioreg_probe()
109 		return -ENOMEM;  in mdio_mux_mmioreg_probe()
113 		dev_err(&pdev->dev, "could not obtain memory map for node %pOF\n",  in mdio_mux_mmioreg_probe()
117 	s->phys = res.start;  in mdio_mux_mmioreg_probe()
119 	s->iosize = resource_size(&res);  in mdio_mux_mmioreg_probe()
120 	if (s->iosize != sizeof(uint8_t) &&  in mdio_mux_mmioreg_probe()
121 	    s->iosize != sizeof(uint16_t) &&  in mdio_mux_mmioreg_probe()
122 	    s->iosize != sizeof(uint32_t)) {  in mdio_mux_mmioreg_probe()
123 		dev_err(&pdev->dev, "only 8/16/32-bit registers are supported\n");  in mdio_mux_mmioreg_probe()
124 		return -EINVAL;  in mdio_mux_mmioreg_probe()
127 	iprop = of_get_property(np, "mux-mask", &len);  in mdio_mux_mmioreg_probe()
129 		dev_err(&pdev->dev, "missing or invalid mux-mask property\n");  in mdio_mux_mmioreg_probe()
130 		return -ENODEV;  in mdio_mux_mmioreg_probe()
132 	if (be32_to_cpup(iprop) >= BIT(s->iosize * 8)) {  in mdio_mux_mmioreg_probe()
133 		dev_err(&pdev->dev, "only 8/16/32-bit registers are supported\n");  in mdio_mux_mmioreg_probe()
134 		return -EINVAL;  in mdio_mux_mmioreg_probe()
136 	s->mask = be32_to_cpup(iprop);  in mdio_mux_mmioreg_probe()
139 	 * Verify that the 'reg' property of each child MDIO bus does not  in mdio_mux_mmioreg_probe()
145 			dev_err(&pdev->dev, "mdio-mux child node %pOF is "  in mdio_mux_mmioreg_probe()
148 			return -ENODEV;  in mdio_mux_mmioreg_probe()
150 		if (be32_to_cpup(iprop) & ~s->mask) {  in mdio_mux_mmioreg_probe()
151 			dev_err(&pdev->dev, "mdio-mux child node %pOF has "  in mdio_mux_mmioreg_probe()
155 			return -ENODEV;  in mdio_mux_mmioreg_probe()
159 	ret = mdio_mux_init(&pdev->dev, pdev->dev.of_node,  in mdio_mux_mmioreg_probe()
161 			    &s->mux_handle, s, NULL);  in mdio_mux_mmioreg_probe()
163 		return dev_err_probe(&pdev->dev, ret,  in mdio_mux_mmioreg_probe()
164 				     "failed to register mdio-mux bus %pOF\n", np);  in mdio_mux_mmioreg_probe()
166 	pdev->dev.platform_data = s;  in mdio_mux_mmioreg_probe()
173 	struct mdio_mux_mmioreg_state *s = dev_get_platdata(&pdev->dev);  in mdio_mux_mmioreg_remove()
175 	mdio_mux_uninit(s->mux_handle);  in mdio_mux_mmioreg_remove()
182 		.compatible = "mdio-mux-mmioreg",
190 		.name		= "mdio-mux-mmioreg",
200 MODULE_DESCRIPTION("Memory-mapped device MDIO MUX driver");