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)
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 */
222 	if (fifosz >= 4096) {
223 		unsigned int rfd, rfa;
224 
225 		mtl_rx_op |= MTL_OP_MODE_EHFC;
226 
227 		/* Set Threshold for Activating Flow Control to min 2 frames,
228 		 * i.e. 1500 * 2 = 3000 bytes.
229 		 *
230 		 * Set Threshold for Deactivating Flow Control to min 1 frame,
231 		 * i.e. 1500 bytes.
232 		 */
233 		switch (fifosz) {
234 		case 4096:
235 			/* This violates the above formula because of FIFO size
236 			 * limit therefore overflow may occur in spite of this.
237 			 */
238 			rfd = 0x03; /* Full-2.5K */
239 			rfa = 0x01; /* Full-1.5K */
240 			break;
241 
242 		case 8192:
243 			rfd = 0x06; /* Full-4K */
244 			rfa = 0x0a; /* Full-6K */
245 			break;
246 
247 		case 16384:
248 			rfd = 0x06; /* Full-4K */
249 			rfa = 0x12; /* Full-10K */
250 			break;
251 
252 		default:
253 			rfd = 0x06; /* Full-4K */
254 			rfa = 0x1e; /* Full-16K */
255 			break;
256 		}
257 
258 		mtl_rx_op &= ~MTL_OP_MODE_RFD_MASK;
259 		mtl_rx_op |= rfd << MTL_OP_MODE_RFD_SHIFT;
260 
261 		mtl_rx_op &= ~MTL_OP_MODE_RFA_MASK;
262 		mtl_rx_op |= rfa << MTL_OP_MODE_RFA_SHIFT;
263 	}
264 
265 	writel(mtl_rx_op, ioaddr + MTL_CHAN_RX_OP_MODE(channel));
266 
267 	/* Enable MTL RX overflow */
268 	mtl_rx_int = readl(ioaddr + MTL_CHAN_INT_CTRL(channel));
269 	writel(mtl_rx_int | MTL_RX_OVERFLOW_INT_EN,
270 	       ioaddr + MTL_CHAN_INT_CTRL(channel));
271 }
272 
273 static void dwmac4_dma_tx_chan_op_mode(void __iomem *ioaddr, int mode,
274 				       u32 channel)
275 {
276 	u32 mtl_tx_op = readl(ioaddr + MTL_CHAN_TX_OP_MODE(channel));
277 
278 	if (mode == SF_DMA_MODE) {
279 		pr_debug("GMAC: enable TX store and forward mode\n");
280 		/* Transmit COE type 2 cannot be done in cut-through mode. */
281 		mtl_tx_op |= MTL_OP_MODE_TSF;
282 	} else {
283 		pr_debug("GMAC: disabling TX SF (threshold %d)\n", mode);
284 		mtl_tx_op &= ~MTL_OP_MODE_TSF;
285 		mtl_tx_op &= MTL_OP_MODE_TTC_MASK;
286 		/* Set the transmit threshold */
287 		if (mode <= 32)
288 			mtl_tx_op |= MTL_OP_MODE_TTC_32;
289 		else if (mode <= 64)
290 			mtl_tx_op |= MTL_OP_MODE_TTC_64;
291 		else if (mode <= 96)
292 			mtl_tx_op |= MTL_OP_MODE_TTC_96;
293 		else if (mode <= 128)
294 			mtl_tx_op |= MTL_OP_MODE_TTC_128;
295 		else if (mode <= 192)
296 			mtl_tx_op |= MTL_OP_MODE_TTC_192;
297 		else if (mode <= 256)
298 			mtl_tx_op |= MTL_OP_MODE_TTC_256;
299 		else if (mode <= 384)
300 			mtl_tx_op |= MTL_OP_MODE_TTC_384;
301 		else
302 			mtl_tx_op |= MTL_OP_MODE_TTC_512;
303 	}
304 	/* For an IP with DWC_EQOS_NUM_TXQ == 1, the fields TXQEN and TQS are RO
305 	 * with reset values: TXQEN on, TQS == DWC_EQOS_TXFIFO_SIZE.
306 	 * For an IP with DWC_EQOS_NUM_TXQ > 1, the fields TXQEN and TQS are R/W
307 	 * with reset values: TXQEN off, TQS 256 bytes.
308 	 *
309 	 * Write the bits in both cases, since it will have no effect when RO.
310 	 * For DWC_EQOS_NUM_TXQ > 1, the top bits in MTL_OP_MODE_TQS_MASK might
311 	 * be RO, however, writing the whole TQS field will result in a value
312 	 * equal to DWC_EQOS_TXFIFO_SIZE, just like for DWC_EQOS_NUM_TXQ == 1.
313 	 */
314 	mtl_tx_op |= MTL_OP_MODE_TXQEN | MTL_OP_MODE_TQS_MASK;
315 	writel(mtl_tx_op, ioaddr +  MTL_CHAN_TX_OP_MODE(channel));
316 }
317 
318 static void dwmac4_get_hw_feature(void __iomem *ioaddr,
319 				  struct dma_features *dma_cap)
320 {
321 	u32 hw_cap = readl(ioaddr + GMAC_HW_FEATURE0);
322 
323 	/*  MAC HW feature0 */
324 	dma_cap->mbps_10_100 = (hw_cap & GMAC_HW_FEAT_MIISEL);
325 	dma_cap->mbps_1000 = (hw_cap & GMAC_HW_FEAT_GMIISEL) >> 1;
326 	dma_cap->half_duplex = (hw_cap & GMAC_HW_FEAT_HDSEL) >> 2;
327 	dma_cap->hash_filter = (hw_cap & GMAC_HW_FEAT_VLHASH) >> 4;
328 	dma_cap->multi_addr = (hw_cap & GMAC_HW_FEAT_ADDMAC) >> 18;
329 	dma_cap->pcs = (hw_cap & GMAC_HW_FEAT_PCSSEL) >> 3;
330 	dma_cap->sma_mdio = (hw_cap & GMAC_HW_FEAT_SMASEL) >> 5;
331 	dma_cap->pmt_remote_wake_up = (hw_cap & GMAC_HW_FEAT_RWKSEL) >> 6;
332 	dma_cap->pmt_magic_frame = (hw_cap & GMAC_HW_FEAT_MGKSEL) >> 7;
333 	/* MMC */
334 	dma_cap->rmon = (hw_cap & GMAC_HW_FEAT_MMCSEL) >> 8;
335 	/* IEEE 1588-2008 */
336 	dma_cap->atime_stamp = (hw_cap & GMAC_HW_FEAT_TSSEL) >> 12;
337 	/* 802.3az - Energy-Efficient Ethernet (EEE) */
338 	dma_cap->eee = (hw_cap & GMAC_HW_FEAT_EEESEL) >> 13;
339 	/* TX and RX csum */
340 	dma_cap->tx_coe = (hw_cap & GMAC_HW_FEAT_TXCOSEL) >> 14;
341 	dma_cap->rx_coe =  (hw_cap & GMAC_HW_FEAT_RXCOESEL) >> 16;
342 
343 	/* MAC HW feature1 */
344 	hw_cap = readl(ioaddr + GMAC_HW_FEATURE1);
345 	dma_cap->av = (hw_cap & GMAC_HW_FEAT_AVSEL) >> 20;
346 	dma_cap->tsoen = (hw_cap & GMAC_HW_TSOEN) >> 18;
347 	/* RX and TX FIFO sizes are encoded as log2(n / 128). Undo that by
348 	 * shifting and store the sizes in bytes.
349 	 */
350 	dma_cap->tx_fifo_size = 128 << ((hw_cap & GMAC_HW_TXFIFOSIZE) >> 6);
351 	dma_cap->rx_fifo_size = 128 << ((hw_cap & GMAC_HW_RXFIFOSIZE) >> 0);
352 	/* MAC HW feature2 */
353 	hw_cap = readl(ioaddr + GMAC_HW_FEATURE2);
354 	/* TX and RX number of channels */
355 	dma_cap->number_rx_channel =
356 		((hw_cap & GMAC_HW_FEAT_RXCHCNT) >> 12) + 1;
357 	dma_cap->number_tx_channel =
358 		((hw_cap & GMAC_HW_FEAT_TXCHCNT) >> 18) + 1;
359 	/* TX and RX number of queues */
360 	dma_cap->number_rx_queues =
361 		((hw_cap & GMAC_HW_FEAT_RXQCNT) >> 0) + 1;
362 	dma_cap->number_tx_queues =
363 		((hw_cap & GMAC_HW_FEAT_TXQCNT) >> 6) + 1;
364 
365 	/* IEEE 1588-2002 */
366 	dma_cap->time_stamp = 0;
367 }
368 
369 /* Enable/disable TSO feature and set MSS */
370 static void dwmac4_enable_tso(void __iomem *ioaddr, bool en, u32 chan)
371 {
372 	u32 value;
373 
374 	if (en) {
375 		/* enable TSO */
376 		value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
377 		writel(value | DMA_CONTROL_TSE,
378 		       ioaddr + DMA_CHAN_TX_CONTROL(chan));
379 	} else {
380 		/* enable TSO */
381 		value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
382 		writel(value & ~DMA_CONTROL_TSE,
383 		       ioaddr + DMA_CHAN_TX_CONTROL(chan));
384 	}
385 }
386 
387 const struct stmmac_dma_ops dwmac4_dma_ops = {
388 	.reset = dwmac4_dma_reset,
389 	.init = dwmac4_dma_init,
390 	.init_chan = dwmac4_dma_init_channel,
391 	.init_rx_chan = dwmac4_dma_init_rx_chan,
392 	.init_tx_chan = dwmac4_dma_init_tx_chan,
393 	.axi = dwmac4_dma_axi,
394 	.dump_regs = dwmac4_dump_dma_regs,
395 	.dma_rx_mode = dwmac4_dma_rx_chan_op_mode,
396 	.dma_tx_mode = dwmac4_dma_tx_chan_op_mode,
397 	.enable_dma_irq = dwmac4_enable_dma_irq,
398 	.disable_dma_irq = dwmac4_disable_dma_irq,
399 	.start_tx = dwmac4_dma_start_tx,
400 	.stop_tx = dwmac4_dma_stop_tx,
401 	.start_rx = dwmac4_dma_start_rx,
402 	.stop_rx = dwmac4_dma_stop_rx,
403 	.dma_interrupt = dwmac4_dma_interrupt,
404 	.get_hw_feature = dwmac4_get_hw_feature,
405 	.rx_watchdog = dwmac4_rx_watchdog,
406 	.set_rx_ring_len = dwmac4_set_rx_ring_len,
407 	.set_tx_ring_len = dwmac4_set_tx_ring_len,
408 	.set_rx_tail_ptr = dwmac4_set_rx_tail_ptr,
409 	.set_tx_tail_ptr = dwmac4_set_tx_tail_ptr,
410 	.enable_tso = dwmac4_enable_tso,
411 };
412 
413 const struct stmmac_dma_ops dwmac410_dma_ops = {
414 	.reset = dwmac4_dma_reset,
415 	.init = dwmac4_dma_init,
416 	.init_chan = dwmac4_dma_init_channel,
417 	.init_rx_chan = dwmac4_dma_init_rx_chan,
418 	.init_tx_chan = dwmac4_dma_init_tx_chan,
419 	.axi = dwmac4_dma_axi,
420 	.dump_regs = dwmac4_dump_dma_regs,
421 	.dma_rx_mode = dwmac4_dma_rx_chan_op_mode,
422 	.dma_tx_mode = dwmac4_dma_tx_chan_op_mode,
423 	.enable_dma_irq = dwmac410_enable_dma_irq,
424 	.disable_dma_irq = dwmac4_disable_dma_irq,
425 	.start_tx = dwmac4_dma_start_tx,
426 	.stop_tx = dwmac4_dma_stop_tx,
427 	.start_rx = dwmac4_dma_start_rx,
428 	.stop_rx = dwmac4_dma_stop_rx,
429 	.dma_interrupt = dwmac4_dma_interrupt,
430 	.get_hw_feature = dwmac4_get_hw_feature,
431 	.rx_watchdog = dwmac4_rx_watchdog,
432 	.set_rx_ring_len = dwmac4_set_rx_ring_len,
433 	.set_tx_ring_len = dwmac4_set_tx_ring_len,
434 	.set_rx_tail_ptr = dwmac4_set_rx_tail_ptr,
435 	.set_tx_tail_ptr = dwmac4_set_tx_tail_ptr,
436 	.enable_tso = dwmac4_enable_tso,
437 };
438