xref: /linux/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c (revision a34b0e4e21d6be3c3d620aa7f9dfbf0e9550c19e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*******************************************************************************
3   This is the driver for the MAC 10/100 on-chip Ethernet controller
4   currently tested on all the ST boards based on STb7109 and stx7200 SoCs.
5 
6   DWC Ether MAC 10/100 Universal version 4.0 has been used for developing
7   this code.
8 
9   This contains the functions to handle the dma.
10 
11   Copyright (C) 2007-2009  STMicroelectronics Ltd
12 
13 
14   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
15 *******************************************************************************/
16 
17 #include <linux/io.h>
18 #include "dwmac100.h"
19 #include "dwmac_dma.h"
20 
21 static void dwmac100_dma_init(void __iomem *ioaddr,
22 			      struct stmmac_dma_cfg *dma_cfg)
23 {
24 	/* Enable Application Access by writing to DMA CSR0 */
25 	writel(DMA_BUS_MODE_DEFAULT |
26 	       FIELD_PREP(DMA_BUS_MODE_PBL_MASK, dma_cfg->pbl),
27 	       ioaddr + DMA_BUS_MODE);
28 
29 	/* Mask interrupts by writing to CSR7 */
30 	writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
31 }
32 
33 static void dwmac100_dma_init_rx(struct stmmac_priv *priv, void __iomem *ioaddr,
34 				 struct stmmac_dma_cfg *dma_cfg,
35 				 dma_addr_t dma_rx_phy, u32 chan)
36 {
37 	/* RX descriptor base addr lists must be written into DMA CSR3 */
38 	writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_RCV_BASE_ADDR);
39 }
40 
41 static void dwmac100_dma_init_tx(struct stmmac_priv *priv, void __iomem *ioaddr,
42 				 struct stmmac_dma_cfg *dma_cfg,
43 				 dma_addr_t dma_tx_phy, u32 chan)
44 {
45 	/* TX descriptor base addr lists must be written into DMA CSR4 */
46 	writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_TX_BASE_ADDR);
47 }
48 
49 /* Store and Forward capability is not used at all.
50  *
51  * The transmit threshold can be programmed by setting the TTC bits in the DMA
52  * control register.
53  */
54 static void dwmac100_dma_operation_mode_tx(struct stmmac_priv *priv,
55 					   void __iomem *ioaddr, int mode,
56 					   u32 channel, int fifosz, u8 qmode)
57 {
58 	u32 csr6 = readl(ioaddr + DMA_CONTROL);
59 
60 	if (mode <= 32)
61 		csr6 |= DMA_CONTROL_TTC_32;
62 	else if (mode <= 64)
63 		csr6 |= DMA_CONTROL_TTC_64;
64 	else
65 		csr6 |= DMA_CONTROL_TTC_128;
66 
67 	writel(csr6, ioaddr + DMA_CONTROL);
68 }
69 
70 static void dwmac100_dump_dma_regs(struct stmmac_priv *priv,
71 				   void __iomem *ioaddr, u32 *reg_space)
72 {
73 	int i;
74 
75 	for (i = 0; i < NUM_DWMAC100_DMA_REGS; i++)
76 		reg_space[DMA_BUS_MODE / 4 + i] =
77 			readl(ioaddr + DMA_BUS_MODE + i * 4);
78 
79 	reg_space[DMA_CUR_TX_BUF_ADDR / 4] =
80 		readl(ioaddr + DMA_CUR_TX_BUF_ADDR);
81 	reg_space[DMA_CUR_RX_BUF_ADDR / 4] =
82 		readl(ioaddr + DMA_CUR_RX_BUF_ADDR);
83 }
84 
85 /* DMA controller has two counters to track the number of the missed frames. */
86 static void dwmac100_dma_diagnostic_fr(struct stmmac_extra_stats *x,
87 				       void __iomem *ioaddr)
88 {
89 	u32 csr8 = readl(ioaddr + DMA_MISSED_FRAME_CTR);
90 
91 	if (unlikely(csr8)) {
92 		if (csr8 & DMA_MISSED_FRAME_OVE) {
93 			x->rx_overflow_cntr += 0x800;
94 		} else {
95 			unsigned int ove_cntr;
96 			ove_cntr = ((csr8 & DMA_MISSED_FRAME_OVE_CNTR) >> 17);
97 			x->rx_overflow_cntr += ove_cntr;
98 		}
99 
100 		if (csr8 & DMA_MISSED_FRAME_OVE_M) {
101 			x->rx_missed_cntr += 0xffff;
102 		} else {
103 			unsigned int miss_f = (csr8 & DMA_MISSED_FRAME_M_CNTR);
104 			x->rx_missed_cntr += miss_f;
105 		}
106 	}
107 }
108 
109 const struct stmmac_dma_ops dwmac100_dma_ops = {
110 	.reset = dwmac_dma_reset,
111 	.init = dwmac100_dma_init,
112 	.init_rx_chan = dwmac100_dma_init_rx,
113 	.init_tx_chan = dwmac100_dma_init_tx,
114 	.dump_regs = dwmac100_dump_dma_regs,
115 	.dma_tx_mode = dwmac100_dma_operation_mode_tx,
116 	.dma_diagnostic_fr = dwmac100_dma_diagnostic_fr,
117 	.enable_dma_transmission = dwmac_enable_dma_transmission,
118 	.enable_dma_irq = dwmac_enable_dma_irq,
119 	.disable_dma_irq = dwmac_disable_dma_irq,
120 	.start_tx = dwmac_dma_start_tx,
121 	.stop_tx = dwmac_dma_stop_tx,
122 	.start_rx = dwmac_dma_start_rx,
123 	.stop_rx = dwmac_dma_stop_rx,
124 	.dma_interrupt = dwmac_dma_interrupt,
125 };
126