xref: /linux/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 | (dma_cfg->pbl << DMA_BUS_MODE_PBL_SHIFT),
26 	       ioaddr + DMA_BUS_MODE);
27 
28 	/* Mask interrupts by writing to CSR7 */
29 	writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
30 }
31 
32 static void dwmac100_dma_init_rx(struct stmmac_priv *priv, void __iomem *ioaddr,
33 				 struct stmmac_dma_cfg *dma_cfg,
34 				 dma_addr_t dma_rx_phy, u32 chan)
35 {
36 	/* RX descriptor base addr lists must be written into DMA CSR3 */
37 	writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_RCV_BASE_ADDR);
38 }
39 
40 static void dwmac100_dma_init_tx(struct stmmac_priv *priv, void __iomem *ioaddr,
41 				 struct stmmac_dma_cfg *dma_cfg,
42 				 dma_addr_t dma_tx_phy, u32 chan)
43 {
44 	/* TX descriptor base addr lists must be written into DMA CSR4 */
45 	writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_TX_BASE_ADDR);
46 }
47 
48 /* Store and Forward capability is not used at all.
49  *
50  * The transmit threshold can be programmed by setting the TTC bits in the DMA
51  * control register.
52  */
53 static void dwmac100_dma_operation_mode_tx(struct stmmac_priv *priv,
54 					   void __iomem *ioaddr, int mode,
55 					   u32 channel, int fifosz, u8 qmode)
56 {
57 	u32 csr6 = readl(ioaddr + DMA_CONTROL);
58 
59 	if (mode <= 32)
60 		csr6 |= DMA_CONTROL_TTC_32;
61 	else if (mode <= 64)
62 		csr6 |= DMA_CONTROL_TTC_64;
63 	else
64 		csr6 |= DMA_CONTROL_TTC_128;
65 
66 	writel(csr6, ioaddr + DMA_CONTROL);
67 }
68 
69 static void dwmac100_dump_dma_regs(struct stmmac_priv *priv,
70 				   void __iomem *ioaddr, u32 *reg_space)
71 {
72 	int i;
73 
74 	for (i = 0; i < NUM_DWMAC100_DMA_REGS; i++)
75 		reg_space[DMA_BUS_MODE / 4 + i] =
76 			readl(ioaddr + DMA_BUS_MODE + i * 4);
77 
78 	reg_space[DMA_CUR_TX_BUF_ADDR / 4] =
79 		readl(ioaddr + DMA_CUR_TX_BUF_ADDR);
80 	reg_space[DMA_CUR_RX_BUF_ADDR / 4] =
81 		readl(ioaddr + DMA_CUR_RX_BUF_ADDR);
82 }
83 
84 /* DMA controller has two counters to track the number of the missed frames. */
85 static void dwmac100_dma_diagnostic_fr(struct stmmac_extra_stats *x,
86 				       void __iomem *ioaddr)
87 {
88 	u32 csr8 = readl(ioaddr + DMA_MISSED_FRAME_CTR);
89 
90 	if (unlikely(csr8)) {
91 		if (csr8 & DMA_MISSED_FRAME_OVE) {
92 			x->rx_overflow_cntr += 0x800;
93 		} else {
94 			unsigned int ove_cntr;
95 			ove_cntr = ((csr8 & DMA_MISSED_FRAME_OVE_CNTR) >> 17);
96 			x->rx_overflow_cntr += ove_cntr;
97 		}
98 
99 		if (csr8 & DMA_MISSED_FRAME_OVE_M) {
100 			x->rx_missed_cntr += 0xffff;
101 		} else {
102 			unsigned int miss_f = (csr8 & DMA_MISSED_FRAME_M_CNTR);
103 			x->rx_missed_cntr += miss_f;
104 		}
105 	}
106 }
107 
108 const struct stmmac_dma_ops dwmac100_dma_ops = {
109 	.reset = dwmac_dma_reset,
110 	.init = dwmac100_dma_init,
111 	.init_rx_chan = dwmac100_dma_init_rx,
112 	.init_tx_chan = dwmac100_dma_init_tx,
113 	.dump_regs = dwmac100_dump_dma_regs,
114 	.dma_tx_mode = dwmac100_dma_operation_mode_tx,
115 	.dma_diagnostic_fr = dwmac100_dma_diagnostic_fr,
116 	.enable_dma_transmission = dwmac_enable_dma_transmission,
117 	.enable_dma_irq = dwmac_enable_dma_irq,
118 	.disable_dma_irq = dwmac_disable_dma_irq,
119 	.start_tx = dwmac_dma_start_tx,
120 	.stop_tx = dwmac_dma_stop_tx,
121 	.start_rx = dwmac_dma_start_rx,
122 	.stop_rx = dwmac_dma_stop_rx,
123 	.dma_interrupt = dwmac_dma_interrupt,
124 };
125