1 /*
2  * This is the driver for the GMAC on-chip Ethernet controller for ST SoCs.
3  * DWC Ether MAC version 4.xx  has been used for  developing this code.
4  *
5  * This contains the functions to handle the dma.
6  *
7  * Copyright (C) 2015  STMicroelectronics Ltd
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms and conditions of the GNU General Public License,
11  * version 2, as published by the Free Software Foundation.
12  *
13  * Author: Alexandre Torgue <alexandre.torgue@st.com>
14  */
15 
16 #include <linux/io.h>
17 #include "dwmac4.h"
18 #include "dwmac4_dma.h"
19 
20 static void dwmac4_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
21 {
22 	u32 value = readl(ioaddr + DMA_SYS_BUS_MODE);
23 	int i;
24 
25 	pr_info("dwmac4: Master AXI performs %s burst length\n",
26 		(value & DMA_SYS_BUS_FB) ? "fixed" : "any");
27 
28 	if (axi->axi_lpi_en)
29 		value |= DMA_AXI_EN_LPI;
30 	if (axi->axi_xit_frm)
31 		value |= DMA_AXI_LPI_XIT_FRM;
32 
33 	value &= ~DMA_AXI_WR_OSR_LMT;
34 	value |= (axi->axi_wr_osr_lmt & DMA_AXI_OSR_MAX) <<
35 		 DMA_AXI_WR_OSR_LMT_SHIFT;
36 
37 	value &= ~DMA_AXI_RD_OSR_LMT;
38 	value |= (axi->axi_rd_osr_lmt & DMA_AXI_OSR_MAX) <<
39 		 DMA_AXI_RD_OSR_LMT_SHIFT;
40 
41 	/* Depending on the UNDEF bit the Master AXI will perform any burst
42 	 * length according to the BLEN programmed (by default all BLEN are
43 	 * set).
44 	 */
45 	for (i = 0; i < AXI_BLEN; i++) {
46 		switch (axi->axi_blen[i]) {
47 		case 256:
48 			value |= DMA_AXI_BLEN256;
49 			break;
50 		case 128:
51 			value |= DMA_AXI_BLEN128;
52 			break;
53 		case 64:
54 			value |= DMA_AXI_BLEN64;
55 			break;
56 		case 32:
57 			value |= DMA_AXI_BLEN32;
58 			break;
59 		case 16:
60 			value |= DMA_AXI_BLEN16;
61 			break;
62 		case 8:
63 			value |= DMA_AXI_BLEN8;
64 			break;
65 		case 4:
66 			value |= DMA_AXI_BLEN4;
67 			break;
68 		}
69 	}
70 
71 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
72 }
73 
74 static void dwmac4_dma_init_rx_chan(void __iomem *ioaddr,
75 				    struct stmmac_dma_cfg *dma_cfg,
76 				    u32 dma_rx_phy, u32 chan)
77 {
78 	u32 value;
79 	u32 rxpbl = dma_cfg->rxpbl ?: dma_cfg->pbl;
80 
81 	value = readl(ioaddr + DMA_CHAN_RX_CONTROL(chan));
82 	value = value | (rxpbl << DMA_BUS_MODE_RPBL_SHIFT);
83 	writel(value, ioaddr + DMA_CHAN_RX_CONTROL(chan));
84 
85 	writel(dma_rx_phy, ioaddr + DMA_CHAN_RX_BASE_ADDR(chan));
86 }
87 
88 static void dwmac4_dma_init_tx_chan(void __iomem *ioaddr,
89 				    struct stmmac_dma_cfg *dma_cfg,
90 				    u32 dma_tx_phy, u32 chan)
91 {
92 	u32 value;
93 	u32 txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
94 
95 	value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
96 	value = value | (txpbl << DMA_BUS_MODE_PBL_SHIFT);
97 	writel(value, ioaddr + DMA_CHAN_TX_CONTROL(chan));
98 
99 	writel(dma_tx_phy, ioaddr + DMA_CHAN_TX_BASE_ADDR(chan));
100 }
101 
102 static void dwmac4_dma_init_channel(void __iomem *ioaddr,
103 				    struct stmmac_dma_cfg *dma_cfg, u32 chan)
104 {
105 	u32 value;
106 
107 	/* common channel control register config */
108 	value = readl(ioaddr + DMA_CHAN_CONTROL(chan));
109 	if (dma_cfg->pblx8)
110 		value = value | DMA_BUS_MODE_PBL;
111 	writel(value, ioaddr + DMA_CHAN_CONTROL(chan));
112 
113 	/* Mask interrupts by writing to CSR7 */
114 	writel(DMA_CHAN_INTR_DEFAULT_MASK,
115 	       ioaddr + DMA_CHAN_INTR_ENA(chan));
116 }
117 
118 static void dwmac4_dma_init(void __iomem *ioaddr,
119 			    struct stmmac_dma_cfg *dma_cfg,
120 			    u32 dma_tx, u32 dma_rx, int atds)
121 {
122 	u32 value = readl(ioaddr + DMA_SYS_BUS_MODE);
123 
124 	/* Set the Fixed burst mode */
125 	if (dma_cfg->fixed_burst)
126 		value |= DMA_SYS_BUS_FB;
127 
128 	/* Mixed Burst has no effect when fb is set */
129 	if (dma_cfg->mixed_burst)
130 		value |= DMA_SYS_BUS_MB;
131 
132 	if (dma_cfg->aal)
133 		value |= DMA_SYS_BUS_AAL;
134 
135 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
136 }
137 
138 static void _dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 channel,
139 				  u32 *reg_space)
140 {
141 	reg_space[DMA_CHAN_CONTROL(channel) / 4] =
142 		readl(ioaddr + DMA_CHAN_CONTROL(channel));
143 	reg_space[DMA_CHAN_TX_CONTROL(channel) / 4] =
144 		readl(ioaddr + DMA_CHAN_TX_CONTROL(channel));
145 	reg_space[DMA_CHAN_RX_CONTROL(channel) / 4] =
146 		readl(ioaddr + DMA_CHAN_RX_CONTROL(channel));
147 	reg_space[DMA_CHAN_TX_BASE_ADDR(channel) / 4] =
148 		readl(ioaddr + DMA_CHAN_TX_BASE_ADDR(channel));
149 	reg_space[DMA_CHAN_RX_BASE_ADDR(channel) / 4] =
150 		readl(ioaddr + DMA_CHAN_RX_BASE_ADDR(channel));
151 	reg_space[DMA_CHAN_TX_END_ADDR(channel) / 4] =
152 		readl(ioaddr + DMA_CHAN_TX_END_ADDR(channel));
153 	reg_space[DMA_CHAN_RX_END_ADDR(channel) / 4] =
154 		readl(ioaddr + DMA_CHAN_RX_END_ADDR(channel));
155 	reg_space[DMA_CHAN_TX_RING_LEN(channel) / 4] =
156 		readl(ioaddr + DMA_CHAN_TX_RING_LEN(channel));
157 	reg_space[DMA_CHAN_RX_RING_LEN(channel) / 4] =
158 		readl(ioaddr + DMA_CHAN_RX_RING_LEN(channel));
159 	reg_space[DMA_CHAN_INTR_ENA(channel) / 4] =
160 		readl(ioaddr + DMA_CHAN_INTR_ENA(channel));
161 	reg_space[DMA_CHAN_RX_WATCHDOG(channel) / 4] =
162 		readl(ioaddr + DMA_CHAN_RX_WATCHDOG(channel));
163 	reg_space[DMA_CHAN_SLOT_CTRL_STATUS(channel) / 4] =
164 		readl(ioaddr + DMA_CHAN_SLOT_CTRL_STATUS(channel));
165 	reg_space[DMA_CHAN_CUR_TX_DESC(channel) / 4] =
166 		readl(ioaddr + DMA_CHAN_CUR_TX_DESC(channel));
167 	reg_space[DMA_CHAN_CUR_RX_DESC(channel) / 4] =
168 		readl(ioaddr + DMA_CHAN_CUR_RX_DESC(channel));
169 	reg_space[DMA_CHAN_CUR_TX_BUF_ADDR(channel) / 4] =
170 		readl(ioaddr + DMA_CHAN_CUR_TX_BUF_ADDR(channel));
171 	reg_space[DMA_CHAN_CUR_RX_BUF_ADDR(channel) / 4] =
172 		readl(ioaddr + DMA_CHAN_CUR_RX_BUF_ADDR(channel));
173 	reg_space[DMA_CHAN_STATUS(channel) / 4] =
174 		readl(ioaddr + DMA_CHAN_STATUS(channel));
175 }
176 
177 static void dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 *reg_space)
178 {
179 	int i;
180 
181 	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
182 		_dwmac4_dump_dma_regs(ioaddr, i, reg_space);
183 }
184 
185 static void dwmac4_rx_watchdog(void __iomem *ioaddr, u32 riwt, u32 number_chan)
186 {
187 	u32 chan;
188 
189 	for (chan = 0; chan < number_chan; chan++)
190 		writel(riwt, ioaddr + DMA_CHAN_RX_WATCHDOG(chan));
191 }
192 
193 static void dwmac4_dma_rx_chan_op_mode(void __iomem *ioaddr, int mode,
194 				       u32 channel, int fifosz, u8 qmode)
195 {
196 	unsigned int rqs = fifosz / 256 - 1;
197 	u32 mtl_rx_op, mtl_rx_int;
198 
199 	mtl_rx_op = readl(ioaddr + MTL_CHAN_RX_OP_MODE(channel));
200 
201 	if (mode == SF_DMA_MODE) {
202 		pr_debug("GMAC: enable RX store and forward mode\n");
203 		mtl_rx_op |= MTL_OP_MODE_RSF;
204 	} else {
205 		pr_debug("GMAC: disable RX SF mode (threshold %d)\n", mode);
206 		mtl_rx_op &= ~MTL_OP_MODE_RSF;
207 		mtl_rx_op &= MTL_OP_MODE_RTC_MASK;
208 		if (mode <= 32)
209 			mtl_rx_op |= MTL_OP_MODE_RTC_32;
210 		else if (mode <= 64)
211 			mtl_rx_op |= MTL_OP_MODE_RTC_64;
212 		else if (mode <= 96)
213 			mtl_rx_op |= MTL_OP_MODE_RTC_96;
214 		else
215 			mtl_rx_op |= MTL_OP_MODE_RTC_128;
216 	}
217 
218 	mtl_rx_op &= ~MTL_OP_MODE_RQS_MASK;
219 	mtl_rx_op |= rqs << MTL_OP_MODE_RQS_SHIFT;
220 
221 	/* Enable flow control only if each channel gets 4 KiB or more FIFO and
222 	 * only if channel is not an AVB channel.
223 	 */
224 	if ((fifosz >= 4096) && (qmode != MTL_QUEUE_AVB)) {
225 		unsigned int rfd, rfa;
226 
227 		mtl_rx_op |= MTL_OP_MODE_EHFC;
228 
229 		/* Set Threshold for Activating Flow Control to min 2 frames,
230 		 * i.e. 1500 * 2 = 3000 bytes.
231 		 *
232 		 * Set Threshold for Deactivating Flow Control to min 1 frame,
233 		 * i.e. 1500 bytes.
234 		 */
235 		switch (fifosz) {
236 		case 4096:
237 			/* This violates the above formula because of FIFO size
238 			 * limit therefore overflow may occur in spite of this.
239 			 */
240 			rfd = 0x03; /* Full-2.5K */
241 			rfa = 0x01; /* Full-1.5K */
242 			break;
243 
244 		case 8192:
245 			rfd = 0x06; /* Full-4K */
246 			rfa = 0x0a; /* Full-6K */
247 			break;
248 
249 		case 16384:
250 			rfd = 0x06; /* Full-4K */
251 			rfa = 0x12; /* Full-10K */
252 			break;
253 
254 		default:
255 			rfd = 0x06; /* Full-4K */
256 			rfa = 0x1e; /* Full-16K */
257 			break;
258 		}
259 
260 		mtl_rx_op &= ~MTL_OP_MODE_RFD_MASK;
261 		mtl_rx_op |= rfd << MTL_OP_MODE_RFD_SHIFT;
262 
263 		mtl_rx_op &= ~MTL_OP_MODE_RFA_MASK;
264 		mtl_rx_op |= rfa << MTL_OP_MODE_RFA_SHIFT;
265 	}
266 
267 	writel(mtl_rx_op, ioaddr + MTL_CHAN_RX_OP_MODE(channel));
268 
269 	/* Enable MTL RX overflow */
270 	mtl_rx_int = readl(ioaddr + MTL_CHAN_INT_CTRL(channel));
271 	writel(mtl_rx_int | MTL_RX_OVERFLOW_INT_EN,
272 	       ioaddr + MTL_CHAN_INT_CTRL(channel));
273 }
274 
275 static void dwmac4_dma_tx_chan_op_mode(void __iomem *ioaddr, int mode,
276 				       u32 channel, int fifosz, u8 qmode)
277 {
278 	u32 mtl_tx_op = readl(ioaddr + MTL_CHAN_TX_OP_MODE(channel));
279 	unsigned int tqs = fifosz / 256 - 1;
280 
281 	if (mode == SF_DMA_MODE) {
282 		pr_debug("GMAC: enable TX store and forward mode\n");
283 		/* Transmit COE type 2 cannot be done in cut-through mode. */
284 		mtl_tx_op |= MTL_OP_MODE_TSF;
285 	} else {
286 		pr_debug("GMAC: disabling TX SF (threshold %d)\n", mode);
287 		mtl_tx_op &= ~MTL_OP_MODE_TSF;
288 		mtl_tx_op &= MTL_OP_MODE_TTC_MASK;
289 		/* Set the transmit threshold */
290 		if (mode <= 32)
291 			mtl_tx_op |= MTL_OP_MODE_TTC_32;
292 		else if (mode <= 64)
293 			mtl_tx_op |= MTL_OP_MODE_TTC_64;
294 		else if (mode <= 96)
295 			mtl_tx_op |= MTL_OP_MODE_TTC_96;
296 		else if (mode <= 128)
297 			mtl_tx_op |= MTL_OP_MODE_TTC_128;
298 		else if (mode <= 192)
299 			mtl_tx_op |= MTL_OP_MODE_TTC_192;
300 		else if (mode <= 256)
301 			mtl_tx_op |= MTL_OP_MODE_TTC_256;
302 		else if (mode <= 384)
303 			mtl_tx_op |= MTL_OP_MODE_TTC_384;
304 		else
305 			mtl_tx_op |= MTL_OP_MODE_TTC_512;
306 	}
307 	/* For an IP with DWC_EQOS_NUM_TXQ == 1, the fields TXQEN and TQS are RO
308 	 * with reset values: TXQEN on, TQS == DWC_EQOS_TXFIFO_SIZE.
309 	 * For an IP with DWC_EQOS_NUM_TXQ > 1, the fields TXQEN and TQS are R/W
310 	 * with reset values: TXQEN off, TQS 256 bytes.
311 	 *
312 	 * TXQEN must be written for multi-channel operation and TQS must
313 	 * reflect the available fifo size per queue (total fifo size / number
314 	 * of enabled queues).
315 	 */
316 	mtl_tx_op &= ~MTL_OP_MODE_TXQEN_MASK;
317 	if (qmode != MTL_QUEUE_AVB)
318 		mtl_tx_op |= MTL_OP_MODE_TXQEN;
319 	else
320 		mtl_tx_op |= MTL_OP_MODE_TXQEN_AV;
321 	mtl_tx_op &= ~MTL_OP_MODE_TQS_MASK;
322 	mtl_tx_op |= tqs << MTL_OP_MODE_TQS_SHIFT;
323 
324 	writel(mtl_tx_op, ioaddr +  MTL_CHAN_TX_OP_MODE(channel));
325 }
326 
327 static void dwmac4_get_hw_feature(void __iomem *ioaddr,
328 				  struct dma_features *dma_cap)
329 {
330 	u32 hw_cap = readl(ioaddr + GMAC_HW_FEATURE0);
331 
332 	/*  MAC HW feature0 */
333 	dma_cap->mbps_10_100 = (hw_cap & GMAC_HW_FEAT_MIISEL);
334 	dma_cap->mbps_1000 = (hw_cap & GMAC_HW_FEAT_GMIISEL) >> 1;
335 	dma_cap->half_duplex = (hw_cap & GMAC_HW_FEAT_HDSEL) >> 2;
336 	dma_cap->hash_filter = (hw_cap & GMAC_HW_FEAT_VLHASH) >> 4;
337 	dma_cap->multi_addr = (hw_cap & GMAC_HW_FEAT_ADDMAC) >> 18;
338 	dma_cap->pcs = (hw_cap & GMAC_HW_FEAT_PCSSEL) >> 3;
339 	dma_cap->sma_mdio = (hw_cap & GMAC_HW_FEAT_SMASEL) >> 5;
340 	dma_cap->pmt_remote_wake_up = (hw_cap & GMAC_HW_FEAT_RWKSEL) >> 6;
341 	dma_cap->pmt_magic_frame = (hw_cap & GMAC_HW_FEAT_MGKSEL) >> 7;
342 	/* MMC */
343 	dma_cap->rmon = (hw_cap & GMAC_HW_FEAT_MMCSEL) >> 8;
344 	/* IEEE 1588-2008 */
345 	dma_cap->atime_stamp = (hw_cap & GMAC_HW_FEAT_TSSEL) >> 12;
346 	/* 802.3az - Energy-Efficient Ethernet (EEE) */
347 	dma_cap->eee = (hw_cap & GMAC_HW_FEAT_EEESEL) >> 13;
348 	/* TX and RX csum */
349 	dma_cap->tx_coe = (hw_cap & GMAC_HW_FEAT_TXCOSEL) >> 14;
350 	dma_cap->rx_coe =  (hw_cap & GMAC_HW_FEAT_RXCOESEL) >> 16;
351 
352 	/* MAC HW feature1 */
353 	hw_cap = readl(ioaddr + GMAC_HW_FEATURE1);
354 	dma_cap->av = (hw_cap & GMAC_HW_FEAT_AVSEL) >> 20;
355 	dma_cap->tsoen = (hw_cap & GMAC_HW_TSOEN) >> 18;
356 	/* RX and TX FIFO sizes are encoded as log2(n / 128). Undo that by
357 	 * shifting and store the sizes in bytes.
358 	 */
359 	dma_cap->tx_fifo_size = 128 << ((hw_cap & GMAC_HW_TXFIFOSIZE) >> 6);
360 	dma_cap->rx_fifo_size = 128 << ((hw_cap & GMAC_HW_RXFIFOSIZE) >> 0);
361 	/* MAC HW feature2 */
362 	hw_cap = readl(ioaddr + GMAC_HW_FEATURE2);
363 	/* TX and RX number of channels */
364 	dma_cap->number_rx_channel =
365 		((hw_cap & GMAC_HW_FEAT_RXCHCNT) >> 12) + 1;
366 	dma_cap->number_tx_channel =
367 		((hw_cap & GMAC_HW_FEAT_TXCHCNT) >> 18) + 1;
368 	/* TX and RX number of queues */
369 	dma_cap->number_rx_queues =
370 		((hw_cap & GMAC_HW_FEAT_RXQCNT) >> 0) + 1;
371 	dma_cap->number_tx_queues =
372 		((hw_cap & GMAC_HW_FEAT_TXQCNT) >> 6) + 1;
373 
374 	/* IEEE 1588-2002 */
375 	dma_cap->time_stamp = 0;
376 }
377 
378 /* Enable/disable TSO feature and set MSS */
379 static void dwmac4_enable_tso(void __iomem *ioaddr, bool en, u32 chan)
380 {
381 	u32 value;
382 
383 	if (en) {
384 		/* enable TSO */
385 		value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
386 		writel(value | DMA_CONTROL_TSE,
387 		       ioaddr + DMA_CHAN_TX_CONTROL(chan));
388 	} else {
389 		/* enable TSO */
390 		value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
391 		writel(value & ~DMA_CONTROL_TSE,
392 		       ioaddr + DMA_CHAN_TX_CONTROL(chan));
393 	}
394 }
395 
396 const struct stmmac_dma_ops dwmac4_dma_ops = {
397 	.reset = dwmac4_dma_reset,
398 	.init = dwmac4_dma_init,
399 	.init_chan = dwmac4_dma_init_channel,
400 	.init_rx_chan = dwmac4_dma_init_rx_chan,
401 	.init_tx_chan = dwmac4_dma_init_tx_chan,
402 	.axi = dwmac4_dma_axi,
403 	.dump_regs = dwmac4_dump_dma_regs,
404 	.dma_rx_mode = dwmac4_dma_rx_chan_op_mode,
405 	.dma_tx_mode = dwmac4_dma_tx_chan_op_mode,
406 	.enable_dma_irq = dwmac4_enable_dma_irq,
407 	.disable_dma_irq = dwmac4_disable_dma_irq,
408 	.start_tx = dwmac4_dma_start_tx,
409 	.stop_tx = dwmac4_dma_stop_tx,
410 	.start_rx = dwmac4_dma_start_rx,
411 	.stop_rx = dwmac4_dma_stop_rx,
412 	.dma_interrupt = dwmac4_dma_interrupt,
413 	.get_hw_feature = dwmac4_get_hw_feature,
414 	.rx_watchdog = dwmac4_rx_watchdog,
415 	.set_rx_ring_len = dwmac4_set_rx_ring_len,
416 	.set_tx_ring_len = dwmac4_set_tx_ring_len,
417 	.set_rx_tail_ptr = dwmac4_set_rx_tail_ptr,
418 	.set_tx_tail_ptr = dwmac4_set_tx_tail_ptr,
419 	.enable_tso = dwmac4_enable_tso,
420 };
421 
422 const struct stmmac_dma_ops dwmac410_dma_ops = {
423 	.reset = dwmac4_dma_reset,
424 	.init = dwmac4_dma_init,
425 	.init_chan = dwmac4_dma_init_channel,
426 	.init_rx_chan = dwmac4_dma_init_rx_chan,
427 	.init_tx_chan = dwmac4_dma_init_tx_chan,
428 	.axi = dwmac4_dma_axi,
429 	.dump_regs = dwmac4_dump_dma_regs,
430 	.dma_rx_mode = dwmac4_dma_rx_chan_op_mode,
431 	.dma_tx_mode = dwmac4_dma_tx_chan_op_mode,
432 	.enable_dma_irq = dwmac410_enable_dma_irq,
433 	.disable_dma_irq = dwmac4_disable_dma_irq,
434 	.start_tx = dwmac4_dma_start_tx,
435 	.stop_tx = dwmac4_dma_stop_tx,
436 	.start_rx = dwmac4_dma_start_rx,
437 	.stop_rx = dwmac4_dma_stop_rx,
438 	.dma_interrupt = dwmac4_dma_interrupt,
439 	.get_hw_feature = dwmac4_get_hw_feature,
440 	.rx_watchdog = dwmac4_rx_watchdog,
441 	.set_rx_ring_len = dwmac4_set_rx_ring_len,
442 	.set_tx_ring_len = dwmac4_set_tx_ring_len,
443 	.set_rx_tail_ptr = dwmac4_set_rx_tail_ptr,
444 	.set_tx_tail_ptr = dwmac4_set_tx_tail_ptr,
445 	.enable_tso = dwmac4_enable_tso,
446 };
447