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      1 /* $NetBSD: tegra_apbdma.c,v 1.9 2021/01/27 03:10:19 thorpej Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017 Jared D. McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: tegra_apbdma.c,v 1.9 2021/01/27 03:10:19 thorpej Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/device.h>
     35 #include <sys/intr.h>
     36 #include <sys/systm.h>
     37 #include <sys/kernel.h>
     38 
     39 #include <arm/nvidia/tegra_reg.h>
     40 #include <arm/nvidia/tegra_apbdmareg.h>
     41 #include <arm/nvidia/tegra_var.h>
     42 
     43 #include <dev/fdt/fdtvar.h>
     44 
     45 #define	TEGRA_APBDMA_NCHAN	32
     46 
     47 static void *	tegra_apbdma_acquire(device_t, const void *, size_t,
     48 				     void (*)(void *), void *);
     49 static void	tegra_apbdma_release(device_t, void *);
     50 static int	tegra_apbdma_transfer(device_t, void *,
     51 				      struct fdtbus_dma_req *);
     52 static void	tegra_apbdma_halt(device_t, void *);
     53 
     54 static const struct fdtbus_dma_controller_func tegra_apbdma_funcs = {
     55 	.acquire = tegra_apbdma_acquire,
     56 	.release = tegra_apbdma_release,
     57 	.transfer = tegra_apbdma_transfer,
     58 	.halt = tegra_apbdma_halt
     59 };
     60 
     61 static int	tegra_apbdma_match(device_t, cfdata_t, void *);
     62 static void	tegra_apbdma_attach(device_t, device_t, void *);
     63 
     64 static int	tegra_apbdma_intr(void *);
     65 
     66 struct tegra_apbdma_softc;
     67 
     68 struct tegra_apbdma_chan {
     69 	struct tegra_apbdma_softc *ch_sc;
     70 	u_int			ch_n;
     71 	void			*ch_ih;
     72 	void			(*ch_cb)(void *);
     73 	void			*ch_cbarg;
     74 	u_int			ch_req;
     75 };
     76 
     77 struct tegra_apbdma_softc {
     78 	device_t		sc_dev;
     79 	bus_space_tag_t		sc_bst;
     80 	bus_space_handle_t	sc_bsh;
     81 	int			sc_phandle;
     82 
     83 	struct tegra_apbdma_chan sc_chan[TEGRA_APBDMA_NCHAN];
     84 };
     85 
     86 CFATTACH_DECL_NEW(tegra_apbdma, sizeof(struct tegra_apbdma_softc),
     87 	tegra_apbdma_match, tegra_apbdma_attach, NULL, NULL);
     88 
     89 #define	APBDMA_READ(sc, reg)						\
     90 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
     91 #define	APBDMA_WRITE(sc, reg, val)					\
     92 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
     93 
     94 static const struct device_compatible_entry compat_data[] = {
     95 	{ .compat = "nvidia,tegra210-apbdma" },
     96 	{ .compat = "nvidia,tegra124-apbdma" },
     97 	DEVICE_COMPAT_EOL
     98 };
     99 
    100 static int
    101 tegra_apbdma_match(device_t parent, cfdata_t cf, void *aux)
    102 {
    103 	struct fdt_attach_args * const faa = aux;
    104 
    105 	return of_compatible_match(faa->faa_phandle, compat_data);
    106 }
    107 
    108 static void
    109 tegra_apbdma_attach(device_t parent, device_t self, void *aux)
    110 {
    111 	struct tegra_apbdma_softc *sc = device_private(self);
    112 	struct fdt_attach_args * const faa = aux;
    113 	const int phandle = faa->faa_phandle;
    114 	struct fdtbus_reset *rst;
    115 	struct clk *clk;
    116 	bus_addr_t addr;
    117 	bus_size_t size;
    118 	int error;
    119 	u_int n;
    120 
    121 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    122 		aprint_error(": couldn't get registers\n");
    123 		return;
    124 	}
    125 
    126 	clk = fdtbus_clock_get_index(phandle, 0);
    127 	if (clk == NULL) {
    128 		aprint_error(": couldn't get clock\n");
    129 		return;
    130 	}
    131 	rst = fdtbus_reset_get(phandle, "dma");
    132 	if (rst == NULL) {
    133 		aprint_error(": couldn't get reset dma\n");
    134 		return;
    135 	}
    136 
    137 	fdtbus_reset_assert(rst);
    138 	error = clk_enable(clk);
    139 	if (error) {
    140 		aprint_error(": couldn't enable clock dma: %d\n", error);
    141 		return;
    142 	}
    143 	fdtbus_reset_deassert(rst);
    144 
    145 	sc->sc_dev = self;
    146 	sc->sc_bst = faa->faa_bst;
    147 	sc->sc_phandle = phandle;
    148 	error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
    149 	if (error) {
    150 		aprint_error(": couldn't map %#" PRIxBUSADDR ": %d", addr, error);
    151 		return;
    152 	}
    153 	for (n = 0; n < TEGRA_APBDMA_NCHAN; n++) {
    154 		sc->sc_chan[n].ch_sc = sc;
    155 		sc->sc_chan[n].ch_n = n;
    156 	}
    157 
    158 	aprint_naive("\n");
    159 	aprint_normal(": APBDMA\n");
    160 
    161 	/* Stop all channels */
    162 	for (n = 0; n < TEGRA_APBDMA_NCHAN; n++)
    163 		APBDMA_WRITE(sc, APBDMACHAN_CSR_REG(n), 0);
    164 
    165 	/* Mask interrupts */
    166 	APBDMA_WRITE(sc, APBDMA_IRQ_MASK_REG, 0);
    167 
    168 	/* Global enable */
    169 	APBDMA_WRITE(sc, APBDMA_COMMAND_REG, APBDMA_COMMAND_GEN);
    170 
    171 	fdtbus_register_dma_controller(self, phandle, &tegra_apbdma_funcs);
    172 }
    173 
    174 static int
    175 tegra_apbdma_intr(void *priv)
    176 {
    177 	struct tegra_apbdma_chan *ch = priv;
    178 	struct tegra_apbdma_softc *sc = ch->ch_sc;
    179 	const u_int n = ch->ch_n;
    180 	uint32_t sta;
    181 
    182 	sta = APBDMA_READ(sc, APBDMACHAN_STA_REG(n));
    183 	APBDMA_WRITE(sc, APBDMACHAN_STA_REG(n), sta);	/* clear EOC */
    184 
    185 	ch->ch_cb(ch->ch_cbarg);
    186 
    187 	return 1;
    188 }
    189 
    190 static void *
    191 tegra_apbdma_acquire(device_t dev, const void *data, size_t len,
    192     void (*cb)(void *), void *cbarg)
    193 {
    194 	struct tegra_apbdma_softc *sc = device_private(dev);
    195 	struct tegra_apbdma_chan *ch;
    196 	u_int n;
    197 	char intrstr[128];
    198 
    199 	if (len != 4)
    200 		return NULL;
    201 
    202 	const u_int req = be32dec(data);
    203 	if (req > __SHIFTOUT_MASK(APBDMACHAN_CSR_REQ_SEL))
    204 		return NULL;
    205 
    206 	for (n = 0; n < TEGRA_APBDMA_NCHAN; n++) {
    207 		ch = &sc->sc_chan[n];
    208 		if (ch->ch_ih == NULL)
    209 			break;
    210 	}
    211 	if (n >= TEGRA_APBDMA_NCHAN) {
    212 		aprint_error_dev(dev, "no free DMA channel\n");
    213 		return NULL;
    214 	}
    215 
    216 	if (!fdtbus_intr_str(sc->sc_phandle, n, intrstr, sizeof(intrstr))) {
    217 		aprint_error_dev(dev, "failed to decode interrupt %u\n", n);
    218 		return NULL;
    219 	}
    220 
    221 	ch->ch_ih = fdtbus_intr_establish_xname(sc->sc_phandle, n, IPL_VM,
    222 	    FDT_INTR_MPSAFE, tegra_apbdma_intr, ch, device_xname(dev));
    223 	if (ch->ch_ih == NULL) {
    224 		aprint_error_dev(dev, "failed to establish interrupt on %s\n",
    225 		    intrstr);
    226 		return NULL;
    227 	}
    228 	aprint_normal_dev(dev, "interrupting on %s (channel %u)\n", intrstr, n);
    229 
    230 	ch->ch_cb = cb;
    231 	ch->ch_cbarg = cbarg;
    232 	ch->ch_req = req;
    233 
    234 	/* Unmask interrupts for this channel */
    235 	APBDMA_WRITE(sc, APBDMA_IRQ_MASK_SET_REG, __BIT(n));
    236 
    237 	return ch;
    238 }
    239 static void
    240 tegra_apbdma_release(device_t dev, void *priv)
    241 {
    242 	struct tegra_apbdma_softc *sc = device_private(dev);
    243 	struct tegra_apbdma_chan *ch = priv;
    244 	const u_int n = ch->ch_n;
    245 
    246 	KASSERT(ch->ch_ih != NULL);
    247 
    248 	/* Halt the channel */
    249 	APBDMA_WRITE(sc, APBDMACHAN_CSR_REG(n), 0);
    250 
    251 	/* Mask interrupts for this channel */
    252 	APBDMA_WRITE(sc, APBDMA_IRQ_MASK_CLR_REG, __BIT(n));
    253 
    254 	fdtbus_intr_disestablish(sc->sc_phandle, ch->ch_ih);
    255 
    256 	ch->ch_cb = NULL;
    257 	ch->ch_cbarg = NULL;
    258 }
    259 
    260 static int
    261 tegra_apbdma_transfer(device_t dev, void *priv, struct fdtbus_dma_req *req)
    262 
    263 {
    264 	struct tegra_apbdma_softc *sc = device_private(dev);
    265 	struct tegra_apbdma_chan *ch = priv;
    266 	const u_int n = ch->ch_n;
    267 	uint32_t csr = 0;
    268 	uint32_t csre = 0;
    269 	uint32_t ahb_seq = 0;
    270 	uint32_t apb_seq = 0;
    271 
    272 	/* Scatter-gather not supported */
    273 	if (req->dreq_nsegs != 1)
    274 		return EINVAL;
    275 
    276 	/* Addresses must be aligned to 32-bits */
    277 	if ((req->dreq_segs[0].ds_addr & 3) != 0 ||
    278 	    (req->dreq_dev_phys & 3) != 0)
    279 		return EINVAL;
    280 
    281 	/* Length must be a multiple of 32-bits */
    282 	if ((req->dreq_segs[0].ds_len & 3) != 0)
    283 		return EINVAL;
    284 
    285 	csr |= __SHIFTIN(ch->ch_req, APBDMACHAN_CSR_REQ_SEL);
    286 
    287 	/*
    288 	 * Set DMA transfer direction.
    289 	 * APBDMACHAN_CSR_DIR=0 means "APB read to AHB write", and
    290 	 * APBDMACHAN_CSR_DIR=1 means "AHB read to APB write".
    291 	 */
    292 	if (req->dreq_dir == FDT_DMA_WRITE)
    293 		csr |= APBDMACHAN_CSR_DIR;
    294 
    295 	/*
    296 	 * Generate interrupt when DMA block transfer completes.
    297 	 */
    298 	if (req->dreq_block_irq)
    299 		csr |= APBDMACHAN_CSR_IE_EOC;
    300 
    301 	/*
    302 	 * Single or multiple block transfer
    303 	 */
    304 	if (!req->dreq_block_multi)
    305 		csr |= APBDMACHAN_CSR_ONCE;
    306 
    307 	/*
    308 	 * Flow control enable
    309 	 */
    310 	if (req->dreq_flow)
    311 		csr |= APBDMACHAN_CSR_FLOW;
    312 
    313 	/*
    314 	 * Route interrupt to CPU. 1 = CPU, 0 = COP
    315 	 */
    316 	ahb_seq |= APBDMACHAN_AHB_SEQ_INTR_ENB;
    317 
    318 	/*
    319 	 * AHB is a 32-bit bus.
    320 	 */
    321 	if (req->dreq_mem_opt.opt_bus_width != 32)
    322 		return EINVAL;
    323 	ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_BUS_WIDTH_32,
    324 			     APBDMACHAN_AHB_SEQ_BUS_WIDTH);
    325 
    326 	/*
    327 	 * AHB data swap.
    328 	 */
    329 	if (req->dreq_mem_opt.opt_swap)
    330 		ahb_seq |= APBDMACHAN_AHB_SEQ_DATA_SWAP;
    331 
    332 	/*
    333 	 * AHB burst size.
    334 	 */
    335 	switch (req->dreq_mem_opt.opt_burst_len) {
    336 	case 32:
    337 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_BURST_1,
    338 				     APBDMACHAN_AHB_SEQ_BURST);
    339 		break;
    340 	case 128:
    341 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_BURST_4,
    342 				     APBDMACHAN_AHB_SEQ_BURST);
    343 		break;
    344 	case 256:
    345 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_BURST_8,
    346 				     APBDMACHAN_AHB_SEQ_BURST);
    347 		break;
    348 	default:
    349 		return EINVAL;
    350 	}
    351 
    352 	/*
    353 	 * 2X double buffering mode. Only supported in run-multiple mode
    354 	 * with no-wrap operations.
    355 	 */
    356 	if (req->dreq_mem_opt.opt_dblbuf) {
    357 		if (req->dreq_mem_opt.opt_wrap_len != 0)
    358 			return EINVAL;
    359 		if (!req->dreq_block_multi)
    360 			return EINVAL;
    361 		ahb_seq |= APBDMACHAN_AHB_SEQ_DBL_BUF;
    362 	}
    363 
    364 	/*
    365 	 * AHB address wrap.
    366 	 */
    367 	switch (req->dreq_mem_opt.opt_wrap_len) {
    368 	case 0:
    369 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_WRAP_NO_WRAP,
    370 				     APBDMACHAN_AHB_SEQ_WRAP);
    371 		break;
    372 	case 128:
    373 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_WRAP_32,
    374 				     APBDMACHAN_AHB_SEQ_WRAP);
    375 		break;
    376 	case 256:
    377 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_WRAP_64,
    378 				     APBDMACHAN_AHB_SEQ_WRAP);
    379 		break;
    380 	case 512:
    381 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_WRAP_128,
    382 				     APBDMACHAN_AHB_SEQ_WRAP);
    383 		break;
    384 	case 1024:
    385 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_WRAP_256,
    386 				     APBDMACHAN_AHB_SEQ_WRAP);
    387 		break;
    388 	case 2048:
    389 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_WRAP_512,
    390 				     APBDMACHAN_AHB_SEQ_WRAP);
    391 		break;
    392 	case 4096:
    393 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_WRAP_1024,
    394 				     APBDMACHAN_AHB_SEQ_WRAP);
    395 		break;
    396 	case 8192:
    397 		ahb_seq |= __SHIFTIN(APBDMACHAN_AHB_SEQ_WRAP_2048,
    398 				     APBDMACHAN_AHB_SEQ_WRAP);
    399 		break;
    400 	default:
    401 		return EINVAL;
    402 	}
    403 
    404 	/*
    405 	 * APB bus width.
    406 	 */
    407 	switch (req->dreq_dev_opt.opt_bus_width) {
    408 	case 8:
    409 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_BUS_WIDTH_8,
    410 				     APBDMACHAN_APB_SEQ_BUS_WIDTH);
    411 		break;
    412 	case 16:
    413 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_BUS_WIDTH_16,
    414 				     APBDMACHAN_APB_SEQ_BUS_WIDTH);
    415 		break;
    416 	case 32:
    417 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_BUS_WIDTH_32,
    418 				     APBDMACHAN_APB_SEQ_BUS_WIDTH);
    419 		break;
    420 	default:
    421 		return EINVAL;
    422 	}
    423 
    424 	/*
    425 	 * APB data swap.
    426 	 */
    427 	if (req->dreq_dev_opt.opt_swap)
    428 		apb_seq |= APBDMACHAN_APB_SEQ_DATA_SWAP;
    429 
    430 	/*
    431 	 * APB address wrap-around window.
    432 	 */
    433 	switch (req->dreq_dev_opt.opt_wrap_len) {
    434 	case 0:
    435 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_WRAP_NO_WRAP,
    436 				     APBDMACHAN_APB_SEQ_WRAP);
    437 		break;
    438 	case 4:
    439 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_WRAP_1,
    440 				     APBDMACHAN_APB_SEQ_WRAP);
    441 		break;
    442 	case 8:
    443 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_WRAP_2,
    444 				     APBDMACHAN_APB_SEQ_WRAP);
    445 		break;
    446 	case 16:
    447 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_WRAP_4,
    448 				     APBDMACHAN_APB_SEQ_WRAP);
    449 		break;
    450 	case 32:
    451 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_WRAP_8,
    452 				     APBDMACHAN_APB_SEQ_WRAP);
    453 		break;
    454 	case 64:
    455 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_WRAP_16,
    456 				     APBDMACHAN_APB_SEQ_WRAP);
    457 		break;
    458 	case 128:
    459 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_WRAP_32,
    460 				     APBDMACHAN_APB_SEQ_WRAP);
    461 		break;
    462 	case 256:
    463 		apb_seq |= __SHIFTIN(APBDMACHAN_APB_SEQ_WRAP_64,
    464 				     APBDMACHAN_APB_SEQ_WRAP);
    465 		break;
    466 	default:
    467 		return EINVAL;
    468 	}
    469 
    470 	/*
    471 	 * Program all channel registers before setting the channel enable bit.
    472 	 */
    473 	APBDMA_WRITE(sc, APBDMACHAN_AHB_PTR_REG(n), req->dreq_segs[0].ds_addr);
    474 	APBDMA_WRITE(sc, APBDMACHAN_APB_PTR_REG(n), req->dreq_dev_phys);
    475 	APBDMA_WRITE(sc, APBDMACHAN_AHB_SEQ_REG(n), ahb_seq);
    476 	APBDMA_WRITE(sc, APBDMACHAN_APB_SEQ_REG(n), apb_seq);
    477 	APBDMA_WRITE(sc, APBDMACHAN_WCOUNT_REG(n), req->dreq_segs[0].ds_len);
    478 	APBDMA_WRITE(sc, APBDMACHAN_CSRE_REG(n), csre);
    479 	APBDMA_WRITE(sc, APBDMACHAN_CSR_REG(n), csr | APBDMACHAN_CSR_ENB);
    480 
    481 	return 0;
    482 }
    483 
    484 static void
    485 tegra_apbdma_halt(device_t dev, void *priv)
    486 {
    487 	struct tegra_apbdma_softc *sc = device_private(dev);
    488 	struct tegra_apbdma_chan *ch = priv;
    489 	const u_int n = ch->ch_n;
    490 	uint32_t v;
    491 
    492 	v = APBDMA_READ(sc, APBDMACHAN_CSR_REG(n));
    493 	v &= ~APBDMACHAN_CSR_ENB;
    494 	APBDMA_WRITE(sc, APBDMACHAN_CSR_REG(n), v);
    495 }
    496