1 // SPDX-License-Identifier: GPL-2.0+
2 /* Microchip lan969x Switch driver
3  *
4  * Copyright (c) 2024 Microchip Technology Inc. and its subsidiaries.
5  */
6 
7 #include "lan969x.h"
8 
9 /* Tx clock selectors */
10 #define LAN969X_RGMII_TX_CLK_SEL_125MHZ 1  /* 1000Mbps */
11 #define LAN969X_RGMII_TX_CLK_SEL_25MHZ  2  /* 100Mbps */
12 #define LAN969X_RGMII_TX_CLK_SEL_2M5MHZ 3  /* 10Mbps */
13 
14 /* Port speed selectors */
15 #define LAN969X_RGMII_SPEED_SEL_10 0   /* Select 10Mbps speed */
16 #define LAN969X_RGMII_SPEED_SEL_100 1  /* Select 100Mbps speed */
17 #define LAN969X_RGMII_SPEED_SEL_1000 2 /* Select 1000Mbps speed */
18 
19 /* Clock delay selectors */
20 #define LAN969X_RGMII_CLK_DELAY_SEL_1_0_NS 2  /* Phase shift 45deg */
21 #define LAN969X_RGMII_CLK_DELAY_SEL_1_7_NS 3  /* Phase shift 77deg */
22 #define LAN969X_RGMII_CLK_DELAY_SEL_2_0_NS 4  /* Phase shift 90deg */
23 #define LAN969X_RGMII_CLK_DELAY_SEL_2_5_NS 5  /* Phase shift 112deg */
24 #define LAN969X_RGMII_CLK_DELAY_SEL_3_0_NS 6  /* Phase shift 135deg */
25 #define LAN969X_RGMII_CLK_DELAY_SEL_3_3_NS 7  /* Phase shift 147deg */
26 
27 #define LAN969X_RGMII_PORT_START_IDX 28 /* Index of the first RGMII port */
28 #define LAN969X_RGMII_IFG_TX 4          /* TX Inter Frame Gap value */
29 #define LAN969X_RGMII_IFG_RX1 5         /* RX1 Inter Frame Gap value */
30 #define LAN969X_RGMII_IFG_RX2 1         /* RX2 Inter Frame Gap value */
31 
32 #define RGMII_PORT_IDX(port) ((port)->portno - LAN969X_RGMII_PORT_START_IDX)
33 
34 /* Get the tx clock selector based on the port speed. */
lan969x_rgmii_get_clk_sel(int speed)35 static int lan969x_rgmii_get_clk_sel(int speed)
36 {
37 	return (speed == SPEED_10  ? LAN969X_RGMII_TX_CLK_SEL_2M5MHZ :
38 		speed == SPEED_100 ? LAN969X_RGMII_TX_CLK_SEL_25MHZ :
39 				     LAN969X_RGMII_TX_CLK_SEL_125MHZ);
40 }
41 
42 /* Get the port speed selector based on the port speed. */
lan969x_rgmii_get_speed_sel(int speed)43 static int lan969x_rgmii_get_speed_sel(int speed)
44 {
45 	return (speed == SPEED_10  ? LAN969X_RGMII_SPEED_SEL_10 :
46 		speed == SPEED_100 ? LAN969X_RGMII_SPEED_SEL_100 :
47 				     LAN969X_RGMII_SPEED_SEL_1000);
48 }
49 
50 /* Get the clock delay selector based on the clock delay in picoseconds. */
lan969x_rgmii_get_clk_delay_sel(struct sparx5_port * port,u32 delay_ps,u32 * clk_delay_sel)51 static int lan969x_rgmii_get_clk_delay_sel(struct sparx5_port *port,
52 					   u32 delay_ps, u32 *clk_delay_sel)
53 {
54 	switch (delay_ps) {
55 	case 0:
56 		/* Hardware default selector. */
57 		*clk_delay_sel = LAN969X_RGMII_CLK_DELAY_SEL_2_5_NS;
58 		break;
59 	case 1000:
60 		*clk_delay_sel = LAN969X_RGMII_CLK_DELAY_SEL_1_0_NS;
61 		break;
62 	case 1700:
63 		*clk_delay_sel = LAN969X_RGMII_CLK_DELAY_SEL_1_7_NS;
64 		break;
65 	case 2000:
66 		*clk_delay_sel = LAN969X_RGMII_CLK_DELAY_SEL_2_0_NS;
67 		break;
68 	case 2500:
69 		*clk_delay_sel = LAN969X_RGMII_CLK_DELAY_SEL_2_5_NS;
70 		break;
71 	case 3000:
72 		*clk_delay_sel = LAN969X_RGMII_CLK_DELAY_SEL_3_0_NS;
73 		break;
74 	case 3300:
75 		*clk_delay_sel = LAN969X_RGMII_CLK_DELAY_SEL_3_3_NS;
76 		break;
77 	default:
78 		dev_err(port->sparx5->dev, "Invalid RGMII delay: %u", delay_ps);
79 		return -EINVAL;
80 	}
81 
82 	return 0;
83 }
84 
85 /* Configure the RGMII tx clock frequency. */
lan969x_rgmii_tx_clk_config(struct sparx5_port * port,struct sparx5_port_config * conf)86 static void lan969x_rgmii_tx_clk_config(struct sparx5_port *port,
87 					struct sparx5_port_config *conf)
88 {
89 	u32 clk_sel = lan969x_rgmii_get_clk_sel(conf->speed);
90 	u32 idx = RGMII_PORT_IDX(port);
91 
92 	/* Take the RGMII clock domain out of reset and set tx clock
93 	 * frequency.
94 	 */
95 	spx5_rmw(HSIO_WRAP_RGMII_CFG_TX_CLK_CFG_SET(clk_sel) |
96 		 HSIO_WRAP_RGMII_CFG_RGMII_TX_RST_SET(0) |
97 		 HSIO_WRAP_RGMII_CFG_RGMII_RX_RST_SET(0),
98 		 HSIO_WRAP_RGMII_CFG_TX_CLK_CFG |
99 		 HSIO_WRAP_RGMII_CFG_RGMII_TX_RST |
100 		 HSIO_WRAP_RGMII_CFG_RGMII_RX_RST,
101 		 port->sparx5, HSIO_WRAP_RGMII_CFG(idx));
102 }
103 
104 /* Configure the RGMII port device. */
lan969x_rgmii_port_device_config(struct sparx5_port * port,struct sparx5_port_config * conf)105 static void lan969x_rgmii_port_device_config(struct sparx5_port *port,
106 					     struct sparx5_port_config *conf)
107 {
108 	u32 dtag, dotag, etype, speed_sel, idx = RGMII_PORT_IDX(port);
109 
110 	speed_sel = lan969x_rgmii_get_speed_sel(conf->speed);
111 
112 	etype = (port->vlan_type == SPX5_VLAN_PORT_TYPE_S_CUSTOM ?
113 		 port->custom_etype :
114 		 port->vlan_type == SPX5_VLAN_PORT_TYPE_C ?
115 		 ETH_P_8021Q : ETH_P_8021AD);
116 
117 	dtag = port->max_vlan_tags == SPX5_PORT_MAX_TAGS_TWO;
118 	dotag = port->max_vlan_tags != SPX5_PORT_MAX_TAGS_NONE;
119 
120 	/* Enable the MAC. */
121 	spx5_wr(DEVRGMII_MAC_ENA_CFG_RX_ENA_SET(1) |
122 		DEVRGMII_MAC_ENA_CFG_TX_ENA_SET(1),
123 		port->sparx5, DEVRGMII_MAC_ENA_CFG(idx));
124 
125 	/* Configure the Inter Frame Gap. */
126 	spx5_wr(DEVRGMII_MAC_IFG_CFG_TX_IFG_SET(LAN969X_RGMII_IFG_TX) |
127 		DEVRGMII_MAC_IFG_CFG_RX_IFG1_SET(LAN969X_RGMII_IFG_RX1) |
128 		DEVRGMII_MAC_IFG_CFG_RX_IFG2_SET(LAN969X_RGMII_IFG_RX2),
129 		port->sparx5, DEVRGMII_MAC_IFG_CFG(idx));
130 
131 	/* Configure port data rate. */
132 	spx5_wr(DEVRGMII_DEV_RST_CTRL_SPEED_SEL_SET(speed_sel),
133 		port->sparx5, DEVRGMII_DEV_RST_CTRL(idx));
134 
135 	/* Configure VLAN awareness. */
136 	spx5_wr(DEVRGMII_MAC_TAGS_CFG_TAG_ID_SET(etype) |
137 		DEVRGMII_MAC_TAGS_CFG_PB_ENA_SET(dtag) |
138 		DEVRGMII_MAC_TAGS_CFG_VLAN_AWR_ENA_SET(dotag) |
139 		DEVRGMII_MAC_TAGS_CFG_VLAN_LEN_AWR_ENA_SET(dotag),
140 		port->sparx5,
141 		DEVRGMII_MAC_TAGS_CFG(idx));
142 }
143 
144 /* Configure the RGMII delay lines in the MAC.
145  *
146  * We use the rx-internal-delay-ps" and "tx-internal-delay-ps" properties to
147  * configure the rx and tx delays for the MAC. If these properties are missing
148  * or set to zero, the MAC will not apply any delay.
149  *
150  * The PHY side delays are determined by the PHY mode
151  * (e.g. PHY_INTERFACE_MODE_RGMII_{ID, RXID, TXID}), and ignored by the MAC side
152  * entirely.
153  */
lan969x_rgmii_delay_config(struct sparx5_port * port,struct sparx5_port_config * conf)154 static int lan969x_rgmii_delay_config(struct sparx5_port *port,
155 				      struct sparx5_port_config *conf)
156 {
157 	u32 tx_clk_sel, rx_clk_sel, tx_delay_ps = 0, rx_delay_ps = 0;
158 	u32 idx = RGMII_PORT_IDX(port);
159 	int err;
160 
161 	of_property_read_u32(port->of_node, "rx-internal-delay-ps",
162 			     &rx_delay_ps);
163 
164 	of_property_read_u32(port->of_node, "tx-internal-delay-ps",
165 			     &tx_delay_ps);
166 
167 	err = lan969x_rgmii_get_clk_delay_sel(port, rx_delay_ps, &rx_clk_sel);
168 	if (err)
169 		return err;
170 
171 	err = lan969x_rgmii_get_clk_delay_sel(port, tx_delay_ps, &tx_clk_sel);
172 	if (err)
173 		return err;
174 
175 	/* Configure rx delay. */
176 	spx5_rmw(HSIO_WRAP_DLL_CFG_DLL_RST_SET(0) |
177 		 HSIO_WRAP_DLL_CFG_DLL_ENA_SET(1) |
178 		 HSIO_WRAP_DLL_CFG_DLL_CLK_ENA_SET(!!rx_delay_ps) |
179 		 HSIO_WRAP_DLL_CFG_DLL_CLK_SEL_SET(rx_clk_sel),
180 		 HSIO_WRAP_DLL_CFG_DLL_RST |
181 		 HSIO_WRAP_DLL_CFG_DLL_ENA |
182 		 HSIO_WRAP_DLL_CFG_DLL_CLK_ENA |
183 		 HSIO_WRAP_DLL_CFG_DLL_CLK_SEL,
184 		 port->sparx5, HSIO_WRAP_DLL_CFG(idx, 0));
185 
186 	/* Configure tx delay. */
187 	spx5_rmw(HSIO_WRAP_DLL_CFG_DLL_RST_SET(0) |
188 		 HSIO_WRAP_DLL_CFG_DLL_ENA_SET(1) |
189 		 HSIO_WRAP_DLL_CFG_DLL_CLK_ENA_SET(!!tx_delay_ps) |
190 		 HSIO_WRAP_DLL_CFG_DLL_CLK_SEL_SET(tx_clk_sel),
191 		 HSIO_WRAP_DLL_CFG_DLL_RST |
192 		 HSIO_WRAP_DLL_CFG_DLL_ENA |
193 		 HSIO_WRAP_DLL_CFG_DLL_CLK_ENA |
194 		 HSIO_WRAP_DLL_CFG_DLL_CLK_SEL,
195 		 port->sparx5, HSIO_WRAP_DLL_CFG(idx, 1));
196 
197 	return 0;
198 }
199 
200 /* Configure GPIO's to be used as RGMII interface. */
lan969x_rgmii_gpio_config(struct sparx5_port * port)201 static void lan969x_rgmii_gpio_config(struct sparx5_port *port)
202 {
203 	u32 idx = RGMII_PORT_IDX(port);
204 
205 	/* Enable the RGMII on the GPIOs. */
206 	spx5_wr(HSIO_WRAP_XMII_CFG_GPIO_XMII_CFG_SET(1), port->sparx5,
207 		HSIO_WRAP_XMII_CFG(!idx));
208 }
209 
lan969x_port_config_rgmii(struct sparx5_port * port,struct sparx5_port_config * conf)210 int lan969x_port_config_rgmii(struct sparx5_port *port,
211 			      struct sparx5_port_config *conf)
212 {
213 	int err;
214 
215 	err = lan969x_rgmii_delay_config(port, conf);
216 	if (err)
217 		return err;
218 
219 	lan969x_rgmii_tx_clk_config(port, conf);
220 	lan969x_rgmii_gpio_config(port);
221 	lan969x_rgmii_port_device_config(port, conf);
222 
223 	return 0;
224 }
225