1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2e5f4ae84SJoachim Eastwood /*
3e5f4ae84SJoachim Eastwood * DMA Router driver for LPC18xx/43xx DMA MUX
4e5f4ae84SJoachim Eastwood *
5e5f4ae84SJoachim Eastwood * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
6e5f4ae84SJoachim Eastwood *
7e5f4ae84SJoachim Eastwood * Based on TI DMA Crossbar driver by:
8e5f4ae84SJoachim Eastwood * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
9e5f4ae84SJoachim Eastwood * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
10e5f4ae84SJoachim Eastwood */
11e5f4ae84SJoachim Eastwood
12e5f4ae84SJoachim Eastwood #include <linux/err.h>
13e5f4ae84SJoachim Eastwood #include <linux/init.h>
14e5f4ae84SJoachim Eastwood #include <linux/mfd/syscon.h>
15*897500c7SRob Herring #include <linux/of.h>
16e5f4ae84SJoachim Eastwood #include <linux/of_dma.h>
17*897500c7SRob Herring #include <linux/of_platform.h>
18*897500c7SRob Herring #include <linux/platform_device.h>
19e5f4ae84SJoachim Eastwood #include <linux/regmap.h>
20e5f4ae84SJoachim Eastwood #include <linux/spinlock.h>
21e5f4ae84SJoachim Eastwood
22e5f4ae84SJoachim Eastwood /* CREG register offset and macros for mux manipulation */
23e5f4ae84SJoachim Eastwood #define LPC18XX_CREG_DMAMUX 0x11c
24e5f4ae84SJoachim Eastwood #define LPC18XX_DMAMUX_VAL(v, n) ((v) << (n * 2))
25e5f4ae84SJoachim Eastwood #define LPC18XX_DMAMUX_MASK(n) (0x3 << (n * 2))
26e5f4ae84SJoachim Eastwood #define LPC18XX_DMAMUX_MAX_VAL 0x3
27e5f4ae84SJoachim Eastwood
28e5f4ae84SJoachim Eastwood struct lpc18xx_dmamux {
29e5f4ae84SJoachim Eastwood u32 value;
30e5f4ae84SJoachim Eastwood bool busy;
31e5f4ae84SJoachim Eastwood };
32e5f4ae84SJoachim Eastwood
33e5f4ae84SJoachim Eastwood struct lpc18xx_dmamux_data {
34e5f4ae84SJoachim Eastwood struct dma_router dmarouter;
35e5f4ae84SJoachim Eastwood struct lpc18xx_dmamux *muxes;
36e5f4ae84SJoachim Eastwood u32 dma_master_requests;
37e5f4ae84SJoachim Eastwood u32 dma_mux_requests;
38e5f4ae84SJoachim Eastwood struct regmap *reg;
39e5f4ae84SJoachim Eastwood spinlock_t lock;
40e5f4ae84SJoachim Eastwood };
41e5f4ae84SJoachim Eastwood
lpc18xx_dmamux_free(struct device * dev,void * route_data)42e5f4ae84SJoachim Eastwood static void lpc18xx_dmamux_free(struct device *dev, void *route_data)
43e5f4ae84SJoachim Eastwood {
44e5f4ae84SJoachim Eastwood struct lpc18xx_dmamux_data *dmamux = dev_get_drvdata(dev);
45e5f4ae84SJoachim Eastwood struct lpc18xx_dmamux *mux = route_data;
46e5f4ae84SJoachim Eastwood unsigned long flags;
47e5f4ae84SJoachim Eastwood
48e5f4ae84SJoachim Eastwood spin_lock_irqsave(&dmamux->lock, flags);
49e5f4ae84SJoachim Eastwood mux->busy = false;
50e5f4ae84SJoachim Eastwood spin_unlock_irqrestore(&dmamux->lock, flags);
51e5f4ae84SJoachim Eastwood }
52e5f4ae84SJoachim Eastwood
lpc18xx_dmamux_reserve(struct of_phandle_args * dma_spec,struct of_dma * ofdma)53e5f4ae84SJoachim Eastwood static void *lpc18xx_dmamux_reserve(struct of_phandle_args *dma_spec,
54e5f4ae84SJoachim Eastwood struct of_dma *ofdma)
55e5f4ae84SJoachim Eastwood {
56e5f4ae84SJoachim Eastwood struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
57e5f4ae84SJoachim Eastwood struct lpc18xx_dmamux_data *dmamux = platform_get_drvdata(pdev);
58e5f4ae84SJoachim Eastwood unsigned long flags;
59e5f4ae84SJoachim Eastwood unsigned mux;
60e5f4ae84SJoachim Eastwood
61e5f4ae84SJoachim Eastwood if (dma_spec->args_count != 3) {
62e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "invalid number of dma mux args\n");
63e5f4ae84SJoachim Eastwood return ERR_PTR(-EINVAL);
64e5f4ae84SJoachim Eastwood }
65e5f4ae84SJoachim Eastwood
66e5f4ae84SJoachim Eastwood mux = dma_spec->args[0];
67e5f4ae84SJoachim Eastwood if (mux >= dmamux->dma_master_requests) {
68e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "invalid mux number: %d\n",
69e5f4ae84SJoachim Eastwood dma_spec->args[0]);
70e5f4ae84SJoachim Eastwood return ERR_PTR(-EINVAL);
71e5f4ae84SJoachim Eastwood }
72e5f4ae84SJoachim Eastwood
73e5f4ae84SJoachim Eastwood if (dma_spec->args[1] > LPC18XX_DMAMUX_MAX_VAL) {
74e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "invalid dma mux value: %d\n",
75e5f4ae84SJoachim Eastwood dma_spec->args[1]);
76e5f4ae84SJoachim Eastwood return ERR_PTR(-EINVAL);
77e5f4ae84SJoachim Eastwood }
78e5f4ae84SJoachim Eastwood
79e5f4ae84SJoachim Eastwood /* The of_node_put() will be done in the core for the node */
80e5f4ae84SJoachim Eastwood dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
81e5f4ae84SJoachim Eastwood if (!dma_spec->np) {
82e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "can't get dma master\n");
83e5f4ae84SJoachim Eastwood return ERR_PTR(-EINVAL);
84e5f4ae84SJoachim Eastwood }
85e5f4ae84SJoachim Eastwood
86e5f4ae84SJoachim Eastwood spin_lock_irqsave(&dmamux->lock, flags);
87e5f4ae84SJoachim Eastwood if (dmamux->muxes[mux].busy) {
88e5f4ae84SJoachim Eastwood spin_unlock_irqrestore(&dmamux->lock, flags);
89e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "dma request %u busy with %u.%u\n",
90e5f4ae84SJoachim Eastwood mux, mux, dmamux->muxes[mux].value);
91e5f4ae84SJoachim Eastwood of_node_put(dma_spec->np);
92e5f4ae84SJoachim Eastwood return ERR_PTR(-EBUSY);
93e5f4ae84SJoachim Eastwood }
94e5f4ae84SJoachim Eastwood
95e5f4ae84SJoachim Eastwood dmamux->muxes[mux].busy = true;
96e5f4ae84SJoachim Eastwood dmamux->muxes[mux].value = dma_spec->args[1];
97e5f4ae84SJoachim Eastwood
98e5f4ae84SJoachim Eastwood regmap_update_bits(dmamux->reg, LPC18XX_CREG_DMAMUX,
99e5f4ae84SJoachim Eastwood LPC18XX_DMAMUX_MASK(mux),
100e5f4ae84SJoachim Eastwood LPC18XX_DMAMUX_VAL(dmamux->muxes[mux].value, mux));
101e5f4ae84SJoachim Eastwood spin_unlock_irqrestore(&dmamux->lock, flags);
102e5f4ae84SJoachim Eastwood
103e5f4ae84SJoachim Eastwood dma_spec->args[1] = dma_spec->args[2];
104e5f4ae84SJoachim Eastwood dma_spec->args_count = 2;
105e5f4ae84SJoachim Eastwood
106e5f4ae84SJoachim Eastwood dev_dbg(&pdev->dev, "mapping dmamux %u.%u to dma request %u\n", mux,
107e5f4ae84SJoachim Eastwood dmamux->muxes[mux].value, mux);
108e5f4ae84SJoachim Eastwood
109e5f4ae84SJoachim Eastwood return &dmamux->muxes[mux];
110e5f4ae84SJoachim Eastwood }
111e5f4ae84SJoachim Eastwood
lpc18xx_dmamux_probe(struct platform_device * pdev)112e5f4ae84SJoachim Eastwood static int lpc18xx_dmamux_probe(struct platform_device *pdev)
113e5f4ae84SJoachim Eastwood {
114e5f4ae84SJoachim Eastwood struct device_node *dma_np, *np = pdev->dev.of_node;
115e5f4ae84SJoachim Eastwood struct lpc18xx_dmamux_data *dmamux;
116e5f4ae84SJoachim Eastwood int ret;
117e5f4ae84SJoachim Eastwood
118e5f4ae84SJoachim Eastwood dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
119e5f4ae84SJoachim Eastwood if (!dmamux)
120e5f4ae84SJoachim Eastwood return -ENOMEM;
121e5f4ae84SJoachim Eastwood
122e5f4ae84SJoachim Eastwood dmamux->reg = syscon_regmap_lookup_by_compatible("nxp,lpc1850-creg");
123e5f4ae84SJoachim Eastwood if (IS_ERR(dmamux->reg)) {
124e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "syscon lookup failed\n");
125e5f4ae84SJoachim Eastwood return PTR_ERR(dmamux->reg);
126e5f4ae84SJoachim Eastwood }
127e5f4ae84SJoachim Eastwood
128e5f4ae84SJoachim Eastwood ret = of_property_read_u32(np, "dma-requests",
129e5f4ae84SJoachim Eastwood &dmamux->dma_mux_requests);
130e5f4ae84SJoachim Eastwood if (ret) {
131e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "missing dma-requests property\n");
132e5f4ae84SJoachim Eastwood return ret;
133e5f4ae84SJoachim Eastwood }
134e5f4ae84SJoachim Eastwood
135e5f4ae84SJoachim Eastwood dma_np = of_parse_phandle(np, "dma-masters", 0);
136e5f4ae84SJoachim Eastwood if (!dma_np) {
137e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "can't get dma master\n");
138e5f4ae84SJoachim Eastwood return -ENODEV;
139e5f4ae84SJoachim Eastwood }
140e5f4ae84SJoachim Eastwood
141e5f4ae84SJoachim Eastwood ret = of_property_read_u32(dma_np, "dma-requests",
142e5f4ae84SJoachim Eastwood &dmamux->dma_master_requests);
143e5f4ae84SJoachim Eastwood of_node_put(dma_np);
144e5f4ae84SJoachim Eastwood if (ret) {
145e5f4ae84SJoachim Eastwood dev_err(&pdev->dev, "missing master dma-requests property\n");
146e5f4ae84SJoachim Eastwood return ret;
147e5f4ae84SJoachim Eastwood }
148e5f4ae84SJoachim Eastwood
149e5f4ae84SJoachim Eastwood dmamux->muxes = devm_kcalloc(&pdev->dev, dmamux->dma_master_requests,
150e5f4ae84SJoachim Eastwood sizeof(struct lpc18xx_dmamux),
151e5f4ae84SJoachim Eastwood GFP_KERNEL);
152e5f4ae84SJoachim Eastwood if (!dmamux->muxes)
153e5f4ae84SJoachim Eastwood return -ENOMEM;
154e5f4ae84SJoachim Eastwood
155e5f4ae84SJoachim Eastwood spin_lock_init(&dmamux->lock);
156e5f4ae84SJoachim Eastwood platform_set_drvdata(pdev, dmamux);
157e5f4ae84SJoachim Eastwood dmamux->dmarouter.dev = &pdev->dev;
158e5f4ae84SJoachim Eastwood dmamux->dmarouter.route_free = lpc18xx_dmamux_free;
159e5f4ae84SJoachim Eastwood
160e5f4ae84SJoachim Eastwood return of_dma_router_register(np, lpc18xx_dmamux_reserve,
161e5f4ae84SJoachim Eastwood &dmamux->dmarouter);
162e5f4ae84SJoachim Eastwood }
163e5f4ae84SJoachim Eastwood
164e5f4ae84SJoachim Eastwood static const struct of_device_id lpc18xx_dmamux_match[] = {
165e5f4ae84SJoachim Eastwood { .compatible = "nxp,lpc1850-dmamux" },
166e5f4ae84SJoachim Eastwood {},
167e5f4ae84SJoachim Eastwood };
168e5f4ae84SJoachim Eastwood
169e5f4ae84SJoachim Eastwood static struct platform_driver lpc18xx_dmamux_driver = {
170e5f4ae84SJoachim Eastwood .probe = lpc18xx_dmamux_probe,
171e5f4ae84SJoachim Eastwood .driver = {
172e5f4ae84SJoachim Eastwood .name = "lpc18xx-dmamux",
173e5f4ae84SJoachim Eastwood .of_match_table = lpc18xx_dmamux_match,
174e5f4ae84SJoachim Eastwood },
175e5f4ae84SJoachim Eastwood };
176e5f4ae84SJoachim Eastwood
lpc18xx_dmamux_init(void)177e5f4ae84SJoachim Eastwood static int __init lpc18xx_dmamux_init(void)
178e5f4ae84SJoachim Eastwood {
179e5f4ae84SJoachim Eastwood return platform_driver_register(&lpc18xx_dmamux_driver);
180e5f4ae84SJoachim Eastwood }
181e5f4ae84SJoachim Eastwood arch_initcall(lpc18xx_dmamux_init);
182