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_channel(void __iomem *ioaddr,
75 				    struct stmmac_dma_cfg *dma_cfg,
76 				    u32 dma_tx_phy, u32 dma_rx_phy,
77 				    u32 channel)
78 {
79 	u32 value;
80 	int txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
81 	int rxpbl = dma_cfg->rxpbl ?: dma_cfg->pbl;
82 
83 	/* set PBL for each channels. Currently we affect same configuration
84 	 * on each channel
85 	 */
86 	value = readl(ioaddr + DMA_CHAN_CONTROL(channel));
87 	if (dma_cfg->pblx8)
88 		value = value | DMA_BUS_MODE_PBL;
89 	writel(value, ioaddr + DMA_CHAN_CONTROL(channel));
90 
91 	value = readl(ioaddr + DMA_CHAN_TX_CONTROL(channel));
92 	value = value | (txpbl << DMA_BUS_MODE_PBL_SHIFT);
93 	writel(value, ioaddr + DMA_CHAN_TX_CONTROL(channel));
94 
95 	value = readl(ioaddr + DMA_CHAN_RX_CONTROL(channel));
96 	value = value | (rxpbl << DMA_BUS_MODE_RPBL_SHIFT);
97 	writel(value, ioaddr + DMA_CHAN_RX_CONTROL(channel));
98 
99 	/* Mask interrupts by writing to CSR7 */
100 	writel(DMA_CHAN_INTR_DEFAULT_MASK, ioaddr + DMA_CHAN_INTR_ENA(channel));
101 
102 	writel(dma_tx_phy, ioaddr + DMA_CHAN_TX_BASE_ADDR(channel));
103 	writel(dma_rx_phy, ioaddr + DMA_CHAN_RX_BASE_ADDR(channel));
104 }
105 
106 static void dwmac4_dma_init(void __iomem *ioaddr,
107 			    struct stmmac_dma_cfg *dma_cfg,
108 			    u32 dma_tx, u32 dma_rx, int atds)
109 {
110 	u32 value = readl(ioaddr + DMA_SYS_BUS_MODE);
111 	int i;
112 
113 	/* Set the Fixed burst mode */
114 	if (dma_cfg->fixed_burst)
115 		value |= DMA_SYS_BUS_FB;
116 
117 	/* Mixed Burst has no effect when fb is set */
118 	if (dma_cfg->mixed_burst)
119 		value |= DMA_SYS_BUS_MB;
120 
121 	if (dma_cfg->aal)
122 		value |= DMA_SYS_BUS_AAL;
123 
124 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
125 
126 	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
127 		dwmac4_dma_init_channel(ioaddr, dma_cfg, dma_tx, dma_rx, i);
128 }
129 
130 static void _dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 channel)
131 {
132 	pr_debug(" Channel %d\n", channel);
133 	pr_debug("\tDMA_CHAN_CONTROL, offset: 0x%x, val: 0x%x\n", 0,
134 		 readl(ioaddr + DMA_CHAN_CONTROL(channel)));
135 	pr_debug("\tDMA_CHAN_TX_CONTROL, offset: 0x%x, val: 0x%x\n", 0x4,
136 		 readl(ioaddr + DMA_CHAN_TX_CONTROL(channel)));
137 	pr_debug("\tDMA_CHAN_RX_CONTROL, offset: 0x%x, val: 0x%x\n", 0x8,
138 		 readl(ioaddr + DMA_CHAN_RX_CONTROL(channel)));
139 	pr_debug("\tDMA_CHAN_TX_BASE_ADDR, offset: 0x%x, val: 0x%x\n", 0x14,
140 		 readl(ioaddr + DMA_CHAN_TX_BASE_ADDR(channel)));
141 	pr_debug("\tDMA_CHAN_RX_BASE_ADDR, offset: 0x%x, val: 0x%x\n", 0x1c,
142 		 readl(ioaddr + DMA_CHAN_RX_BASE_ADDR(channel)));
143 	pr_debug("\tDMA_CHAN_TX_END_ADDR, offset: 0x%x, val: 0x%x\n", 0x20,
144 		 readl(ioaddr + DMA_CHAN_TX_END_ADDR(channel)));
145 	pr_debug("\tDMA_CHAN_RX_END_ADDR, offset: 0x%x, val: 0x%x\n", 0x28,
146 		 readl(ioaddr + DMA_CHAN_RX_END_ADDR(channel)));
147 	pr_debug("\tDMA_CHAN_TX_RING_LEN, offset: 0x%x, val: 0x%x\n", 0x2c,
148 		 readl(ioaddr + DMA_CHAN_TX_RING_LEN(channel)));
149 	pr_debug("\tDMA_CHAN_RX_RING_LEN, offset: 0x%x, val: 0x%x\n", 0x30,
150 		 readl(ioaddr + DMA_CHAN_RX_RING_LEN(channel)));
151 	pr_debug("\tDMA_CHAN_INTR_ENA, offset: 0x%x, val: 0x%x\n", 0x34,
152 		 readl(ioaddr + DMA_CHAN_INTR_ENA(channel)));
153 	pr_debug("\tDMA_CHAN_RX_WATCHDOG, offset: 0x%x, val: 0x%x\n", 0x38,
154 		 readl(ioaddr + DMA_CHAN_RX_WATCHDOG(channel)));
155 	pr_debug("\tDMA_CHAN_SLOT_CTRL_STATUS, offset: 0x%x, val: 0x%x\n", 0x3c,
156 		 readl(ioaddr + DMA_CHAN_SLOT_CTRL_STATUS(channel)));
157 	pr_debug("\tDMA_CHAN_CUR_TX_DESC, offset: 0x%x, val: 0x%x\n", 0x44,
158 		 readl(ioaddr + DMA_CHAN_CUR_TX_DESC(channel)));
159 	pr_debug("\tDMA_CHAN_CUR_RX_DESC, offset: 0x%x, val: 0x%x\n", 0x4c,
160 		 readl(ioaddr + DMA_CHAN_CUR_RX_DESC(channel)));
161 	pr_debug("\tDMA_CHAN_CUR_TX_BUF_ADDR, offset: 0x%x, val: 0x%x\n", 0x54,
162 		 readl(ioaddr + DMA_CHAN_CUR_TX_BUF_ADDR(channel)));
163 	pr_debug("\tDMA_CHAN_CUR_RX_BUF_ADDR, offset: 0x%x, val: 0x%x\n", 0x5c,
164 		 readl(ioaddr + DMA_CHAN_CUR_RX_BUF_ADDR(channel)));
165 	pr_debug("\tDMA_CHAN_STATUS, offset: 0x%x, val: 0x%x\n", 0x60,
166 		 readl(ioaddr + DMA_CHAN_STATUS(channel)));
167 }
168 
169 static void dwmac4_dump_dma_regs(void __iomem *ioaddr)
170 {
171 	int i;
172 
173 	pr_debug(" GMAC4 DMA registers\n");
174 
175 	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
176 		_dwmac4_dump_dma_regs(ioaddr, i);
177 }
178 
179 static void dwmac4_rx_watchdog(void __iomem *ioaddr, u32 riwt)
180 {
181 	int i;
182 
183 	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
184 		writel(riwt, ioaddr + DMA_CHAN_RX_WATCHDOG(i));
185 }
186 
187 static void dwmac4_dma_chan_op_mode(void __iomem *ioaddr, int txmode,
188 				    int rxmode, u32 channel)
189 {
190 	u32 mtl_tx_op, mtl_rx_op, mtl_rx_int;
191 
192 	/* Following code only done for channel 0, other channels not yet
193 	 * supported.
194 	 */
195 	mtl_tx_op = readl(ioaddr + MTL_CHAN_TX_OP_MODE(channel));
196 
197 	if (txmode == SF_DMA_MODE) {
198 		pr_debug("GMAC: enable TX store and forward mode\n");
199 		/* Transmit COE type 2 cannot be done in cut-through mode. */
200 		mtl_tx_op |= MTL_OP_MODE_TSF;
201 	} else {
202 		pr_debug("GMAC: disabling TX SF (threshold %d)\n", txmode);
203 		mtl_tx_op &= ~MTL_OP_MODE_TSF;
204 		mtl_tx_op &= MTL_OP_MODE_TTC_MASK;
205 		/* Set the transmit threshold */
206 		if (txmode <= 32)
207 			mtl_tx_op |= MTL_OP_MODE_TTC_32;
208 		else if (txmode <= 64)
209 			mtl_tx_op |= MTL_OP_MODE_TTC_64;
210 		else if (txmode <= 96)
211 			mtl_tx_op |= MTL_OP_MODE_TTC_96;
212 		else if (txmode <= 128)
213 			mtl_tx_op |= MTL_OP_MODE_TTC_128;
214 		else if (txmode <= 192)
215 			mtl_tx_op |= MTL_OP_MODE_TTC_192;
216 		else if (txmode <= 256)
217 			mtl_tx_op |= MTL_OP_MODE_TTC_256;
218 		else if (txmode <= 384)
219 			mtl_tx_op |= MTL_OP_MODE_TTC_384;
220 		else
221 			mtl_tx_op |= MTL_OP_MODE_TTC_512;
222 	}
223 	/* For an IP with DWC_EQOS_NUM_TXQ == 1, the fields TXQEN and TQS are RO
224 	 * with reset values: TXQEN on, TQS == DWC_EQOS_TXFIFO_SIZE.
225 	 * For an IP with DWC_EQOS_NUM_TXQ > 1, the fields TXQEN and TQS are R/W
226 	 * with reset values: TXQEN off, TQS 256 bytes.
227 	 *
228 	 * Write the bits in both cases, since it will have no effect when RO.
229 	 * For DWC_EQOS_NUM_TXQ > 1, the top bits in MTL_OP_MODE_TQS_MASK might
230 	 * be RO, however, writing the whole TQS field will result in a value
231 	 * equal to DWC_EQOS_TXFIFO_SIZE, just like for DWC_EQOS_NUM_TXQ == 1.
232 	 */
233 	mtl_tx_op |= MTL_OP_MODE_TXQEN | MTL_OP_MODE_TQS_MASK;
234 	writel(mtl_tx_op, ioaddr +  MTL_CHAN_TX_OP_MODE(channel));
235 
236 	mtl_rx_op = readl(ioaddr + MTL_CHAN_RX_OP_MODE(channel));
237 
238 	if (rxmode == SF_DMA_MODE) {
239 		pr_debug("GMAC: enable RX store and forward mode\n");
240 		mtl_rx_op |= MTL_OP_MODE_RSF;
241 	} else {
242 		pr_debug("GMAC: disable RX SF mode (threshold %d)\n", rxmode);
243 		mtl_rx_op &= ~MTL_OP_MODE_RSF;
244 		mtl_rx_op &= MTL_OP_MODE_RTC_MASK;
245 		if (rxmode <= 32)
246 			mtl_rx_op |= MTL_OP_MODE_RTC_32;
247 		else if (rxmode <= 64)
248 			mtl_rx_op |= MTL_OP_MODE_RTC_64;
249 		else if (rxmode <= 96)
250 			mtl_rx_op |= MTL_OP_MODE_RTC_96;
251 		else
252 			mtl_rx_op |= MTL_OP_MODE_RTC_128;
253 	}
254 
255 	writel(mtl_rx_op, ioaddr + MTL_CHAN_RX_OP_MODE(channel));
256 
257 	/* Enable MTL RX overflow */
258 	mtl_rx_int = readl(ioaddr + MTL_CHAN_INT_CTRL(channel));
259 	writel(mtl_rx_int | MTL_RX_OVERFLOW_INT_EN,
260 	       ioaddr + MTL_CHAN_INT_CTRL(channel));
261 }
262 
263 static void dwmac4_dma_operation_mode(void __iomem *ioaddr, int txmode,
264 				      int rxmode, int rxfifosz)
265 {
266 	/* Only Channel 0 is actually configured and used */
267 	dwmac4_dma_chan_op_mode(ioaddr, txmode, rxmode, 0);
268 }
269 
270 static void dwmac4_get_hw_feature(void __iomem *ioaddr,
271 				  struct dma_features *dma_cap)
272 {
273 	u32 hw_cap = readl(ioaddr + GMAC_HW_FEATURE0);
274 
275 	/*  MAC HW feature0 */
276 	dma_cap->mbps_10_100 = (hw_cap & GMAC_HW_FEAT_MIISEL);
277 	dma_cap->mbps_1000 = (hw_cap & GMAC_HW_FEAT_GMIISEL) >> 1;
278 	dma_cap->half_duplex = (hw_cap & GMAC_HW_FEAT_HDSEL) >> 2;
279 	dma_cap->hash_filter = (hw_cap & GMAC_HW_FEAT_VLHASH) >> 4;
280 	dma_cap->multi_addr = (hw_cap & GMAC_HW_FEAT_ADDMAC) >> 18;
281 	dma_cap->pcs = (hw_cap & GMAC_HW_FEAT_PCSSEL) >> 3;
282 	dma_cap->sma_mdio = (hw_cap & GMAC_HW_FEAT_SMASEL) >> 5;
283 	dma_cap->pmt_remote_wake_up = (hw_cap & GMAC_HW_FEAT_RWKSEL) >> 6;
284 	dma_cap->pmt_magic_frame = (hw_cap & GMAC_HW_FEAT_MGKSEL) >> 7;
285 	/* MMC */
286 	dma_cap->rmon = (hw_cap & GMAC_HW_FEAT_MMCSEL) >> 8;
287 	/* IEEE 1588-2008 */
288 	dma_cap->atime_stamp = (hw_cap & GMAC_HW_FEAT_TSSEL) >> 12;
289 	/* 802.3az - Energy-Efficient Ethernet (EEE) */
290 	dma_cap->eee = (hw_cap & GMAC_HW_FEAT_EEESEL) >> 13;
291 	/* TX and RX csum */
292 	dma_cap->tx_coe = (hw_cap & GMAC_HW_FEAT_TXCOSEL) >> 14;
293 	dma_cap->rx_coe =  (hw_cap & GMAC_HW_FEAT_RXCOESEL) >> 16;
294 
295 	/* MAC HW feature1 */
296 	hw_cap = readl(ioaddr + GMAC_HW_FEATURE1);
297 	dma_cap->av = (hw_cap & GMAC_HW_FEAT_AVSEL) >> 20;
298 	dma_cap->tsoen = (hw_cap & GMAC_HW_TSOEN) >> 18;
299 	/* MAC HW feature2 */
300 	hw_cap = readl(ioaddr + GMAC_HW_FEATURE2);
301 	/* TX and RX number of channels */
302 	dma_cap->number_rx_channel =
303 		((hw_cap & GMAC_HW_FEAT_RXCHCNT) >> 12) + 1;
304 	dma_cap->number_tx_channel =
305 		((hw_cap & GMAC_HW_FEAT_TXCHCNT) >> 18) + 1;
306 
307 	/* IEEE 1588-2002 */
308 	dma_cap->time_stamp = 0;
309 }
310 
311 /* Enable/disable TSO feature and set MSS */
312 static void dwmac4_enable_tso(void __iomem *ioaddr, bool en, u32 chan)
313 {
314 	u32 value;
315 
316 	if (en) {
317 		/* enable TSO */
318 		value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
319 		writel(value | DMA_CONTROL_TSE,
320 		       ioaddr + DMA_CHAN_TX_CONTROL(chan));
321 	} else {
322 		/* enable TSO */
323 		value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan));
324 		writel(value & ~DMA_CONTROL_TSE,
325 		       ioaddr + DMA_CHAN_TX_CONTROL(chan));
326 	}
327 }
328 
329 const struct stmmac_dma_ops dwmac4_dma_ops = {
330 	.reset = dwmac4_dma_reset,
331 	.init = dwmac4_dma_init,
332 	.axi = dwmac4_dma_axi,
333 	.dump_regs = dwmac4_dump_dma_regs,
334 	.dma_mode = dwmac4_dma_operation_mode,
335 	.enable_dma_irq = dwmac4_enable_dma_irq,
336 	.disable_dma_irq = dwmac4_disable_dma_irq,
337 	.start_tx = dwmac4_dma_start_tx,
338 	.stop_tx = dwmac4_dma_stop_tx,
339 	.start_rx = dwmac4_dma_start_rx,
340 	.stop_rx = dwmac4_dma_stop_rx,
341 	.dma_interrupt = dwmac4_dma_interrupt,
342 	.get_hw_feature = dwmac4_get_hw_feature,
343 	.rx_watchdog = dwmac4_rx_watchdog,
344 	.set_rx_ring_len = dwmac4_set_rx_ring_len,
345 	.set_tx_ring_len = dwmac4_set_tx_ring_len,
346 	.set_rx_tail_ptr = dwmac4_set_rx_tail_ptr,
347 	.set_tx_tail_ptr = dwmac4_set_tx_tail_ptr,
348 	.enable_tso = dwmac4_enable_tso,
349 };
350 
351 const struct stmmac_dma_ops dwmac410_dma_ops = {
352 	.reset = dwmac4_dma_reset,
353 	.init = dwmac4_dma_init,
354 	.axi = dwmac4_dma_axi,
355 	.dump_regs = dwmac4_dump_dma_regs,
356 	.dma_mode = dwmac4_dma_operation_mode,
357 	.enable_dma_irq = dwmac410_enable_dma_irq,
358 	.disable_dma_irq = dwmac4_disable_dma_irq,
359 	.start_tx = dwmac4_dma_start_tx,
360 	.stop_tx = dwmac4_dma_stop_tx,
361 	.start_rx = dwmac4_dma_start_rx,
362 	.stop_rx = dwmac4_dma_stop_rx,
363 	.dma_interrupt = dwmac4_dma_interrupt,
364 	.get_hw_feature = dwmac4_get_hw_feature,
365 	.rx_watchdog = dwmac4_rx_watchdog,
366 	.set_rx_ring_len = dwmac4_set_rx_ring_len,
367 	.set_tx_ring_len = dwmac4_set_tx_ring_len,
368 	.set_rx_tail_ptr = dwmac4_set_rx_tail_ptr,
369 	.set_tx_tail_ptr = dwmac4_set_tx_tail_ptr,
370 	.enable_tso = dwmac4_enable_tso,
371 };
372