1 | /* |
2 | * Cavium ThunderX i2c driver. |
3 | * |
4 | * Copyright (C) 2015,2016 Cavium Inc. |
5 | * Authors: Fred Martin <fmartin@caviumnetworks.com> |
6 | * Jan Glauber <jglauber@cavium.com> |
7 | * |
8 | * This file is licensed under the terms of the GNU General Public |
9 | * License version 2. This program is licensed "as is" without any |
10 | * warranty of any kind, whether express or implied. |
11 | */ |
12 | |
13 | #include <linux/acpi.h> |
14 | #include <linux/clk.h> |
15 | #include <linux/delay.h> |
16 | #include <linux/i2c.h> |
17 | #include <linux/i2c-smbus.h> |
18 | #include <linux/interrupt.h> |
19 | #include <linux/kernel.h> |
20 | #include <linux/module.h> |
21 | #include <linux/of_irq.h> |
22 | #include <linux/pci.h> |
23 | |
24 | #include "i2c-octeon-core.h" |
25 | |
26 | #define DRV_NAME "i2c-thunderx" |
27 | |
28 | #define PCI_DEVICE_ID_THUNDER_TWSI 0xa012 |
29 | |
30 | #define SYS_FREQ_DEFAULT 700000000 |
31 | |
32 | #define TWSI_INT_ENA_W1C 0x1028 |
33 | #define TWSI_INT_ENA_W1S 0x1030 |
34 | |
35 | /* |
36 | * Enable the CORE interrupt. |
37 | * The interrupt will be asserted when there is non-STAT_IDLE state in the |
38 | * SW_TWSI_EOP_TWSI_STAT register. |
39 | */ |
40 | static void thunder_i2c_int_enable(struct octeon_i2c *i2c) |
41 | { |
42 | octeon_i2c_writeq_flush(TWSI_INT_CORE_INT, |
43 | addr: i2c->twsi_base + TWSI_INT_ENA_W1S); |
44 | } |
45 | |
46 | /* |
47 | * Disable the CORE interrupt. |
48 | */ |
49 | static void thunder_i2c_int_disable(struct octeon_i2c *i2c) |
50 | { |
51 | octeon_i2c_writeq_flush(TWSI_INT_CORE_INT, |
52 | addr: i2c->twsi_base + TWSI_INT_ENA_W1C); |
53 | } |
54 | |
55 | static void thunder_i2c_hlc_int_enable(struct octeon_i2c *i2c) |
56 | { |
57 | octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT, |
58 | addr: i2c->twsi_base + TWSI_INT_ENA_W1S); |
59 | } |
60 | |
61 | static void thunder_i2c_hlc_int_disable(struct octeon_i2c *i2c) |
62 | { |
63 | octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT, |
64 | addr: i2c->twsi_base + TWSI_INT_ENA_W1C); |
65 | } |
66 | |
67 | static u32 thunderx_i2c_functionality(struct i2c_adapter *adap) |
68 | { |
69 | return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | |
70 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL; |
71 | } |
72 | |
73 | static const struct i2c_algorithm thunderx_i2c_algo = { |
74 | .master_xfer = octeon_i2c_xfer, |
75 | .functionality = thunderx_i2c_functionality, |
76 | }; |
77 | |
78 | static const struct i2c_adapter thunderx_i2c_ops = { |
79 | .owner = THIS_MODULE, |
80 | .name = "ThunderX adapter" , |
81 | .algo = &thunderx_i2c_algo, |
82 | }; |
83 | |
84 | static void thunder_i2c_clock_enable(struct device *dev, struct octeon_i2c *i2c) |
85 | { |
86 | int ret; |
87 | |
88 | if (acpi_disabled) { |
89 | /* DT */ |
90 | i2c->clk = clk_get(dev, NULL); |
91 | if (IS_ERR(ptr: i2c->clk)) { |
92 | i2c->clk = NULL; |
93 | goto skip; |
94 | } |
95 | |
96 | ret = clk_prepare_enable(clk: i2c->clk); |
97 | if (ret) |
98 | goto skip; |
99 | i2c->sys_freq = clk_get_rate(clk: i2c->clk); |
100 | } else { |
101 | /* ACPI */ |
102 | device_property_read_u32(dev, propname: "sclk" , val: &i2c->sys_freq); |
103 | } |
104 | |
105 | skip: |
106 | if (!i2c->sys_freq) |
107 | i2c->sys_freq = SYS_FREQ_DEFAULT; |
108 | } |
109 | |
110 | static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk) |
111 | { |
112 | if (!clk) |
113 | return; |
114 | clk_disable_unprepare(clk); |
115 | clk_put(clk); |
116 | } |
117 | |
118 | static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c, |
119 | struct device_node *node) |
120 | { |
121 | struct i2c_client *ara; |
122 | |
123 | if (!node) |
124 | return -EINVAL; |
125 | |
126 | i2c->alert_data.irq = irq_of_parse_and_map(node, index: 0); |
127 | if (!i2c->alert_data.irq) |
128 | return -EINVAL; |
129 | |
130 | ara = i2c_new_smbus_alert_device(adapter: &i2c->adap, setup: &i2c->alert_data); |
131 | if (IS_ERR(ptr: ara)) |
132 | return PTR_ERR(ptr: ara); |
133 | |
134 | i2c->ara = ara; |
135 | |
136 | return 0; |
137 | } |
138 | |
139 | static int thunder_i2c_smbus_setup(struct octeon_i2c *i2c, |
140 | struct device_node *node) |
141 | { |
142 | /* TODO: ACPI support */ |
143 | if (!acpi_disabled) |
144 | return -EOPNOTSUPP; |
145 | |
146 | return thunder_i2c_smbus_setup_of(i2c, node); |
147 | } |
148 | |
149 | static void thunder_i2c_smbus_remove(struct octeon_i2c *i2c) |
150 | { |
151 | i2c_unregister_device(client: i2c->ara); |
152 | } |
153 | |
154 | static int thunder_i2c_probe_pci(struct pci_dev *pdev, |
155 | const struct pci_device_id *ent) |
156 | { |
157 | struct device *dev = &pdev->dev; |
158 | struct octeon_i2c *i2c; |
159 | int ret; |
160 | |
161 | i2c = devm_kzalloc(dev, size: sizeof(*i2c), GFP_KERNEL); |
162 | if (!i2c) |
163 | return -ENOMEM; |
164 | |
165 | i2c->roff.sw_twsi = 0x1000; |
166 | i2c->roff.twsi_int = 0x1010; |
167 | i2c->roff.sw_twsi_ext = 0x1018; |
168 | |
169 | i2c->dev = dev; |
170 | pci_set_drvdata(pdev, data: i2c); |
171 | ret = pcim_enable_device(pdev); |
172 | if (ret) |
173 | return ret; |
174 | |
175 | ret = pci_request_regions(pdev, DRV_NAME); |
176 | if (ret) |
177 | return ret; |
178 | |
179 | i2c->twsi_base = pcim_iomap(pdev, bar: 0, pci_resource_len(pdev, 0)); |
180 | if (!i2c->twsi_base) |
181 | return -EINVAL; |
182 | |
183 | thunder_i2c_clock_enable(dev, i2c); |
184 | ret = device_property_read_u32(dev, propname: "clock-frequency" , val: &i2c->twsi_freq); |
185 | if (ret) |
186 | i2c->twsi_freq = I2C_MAX_STANDARD_MODE_FREQ; |
187 | |
188 | init_waitqueue_head(&i2c->queue); |
189 | |
190 | i2c->int_enable = thunder_i2c_int_enable; |
191 | i2c->int_disable = thunder_i2c_int_disable; |
192 | i2c->hlc_int_enable = thunder_i2c_hlc_int_enable; |
193 | i2c->hlc_int_disable = thunder_i2c_hlc_int_disable; |
194 | |
195 | ret = pci_alloc_irq_vectors(dev: pdev, min_vecs: 1, max_vecs: 1, PCI_IRQ_MSIX); |
196 | if (ret < 0) |
197 | goto error; |
198 | |
199 | ret = devm_request_irq(dev, irq: pci_irq_vector(dev: pdev, nr: 0), handler: octeon_i2c_isr, irqflags: 0, |
200 | DRV_NAME, dev_id: i2c); |
201 | if (ret) |
202 | goto error; |
203 | |
204 | ret = octeon_i2c_init_lowlevel(i2c); |
205 | if (ret) |
206 | goto error; |
207 | |
208 | octeon_i2c_set_clock(i2c); |
209 | |
210 | i2c->adap = thunderx_i2c_ops; |
211 | i2c->adap.retries = 5; |
212 | i2c->adap.class = I2C_CLASS_HWMON; |
213 | i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info; |
214 | i2c->adap.dev.parent = dev; |
215 | i2c->adap.dev.of_node = pdev->dev.of_node; |
216 | i2c->adap.dev.fwnode = dev->fwnode; |
217 | snprintf(buf: i2c->adap.name, size: sizeof(i2c->adap.name), |
218 | fmt: "Cavium ThunderX i2c adapter at %s" , dev_name(dev)); |
219 | i2c_set_adapdata(adap: &i2c->adap, data: i2c); |
220 | |
221 | ret = i2c_add_adapter(adap: &i2c->adap); |
222 | if (ret) |
223 | goto error; |
224 | |
225 | dev_info(i2c->dev, "Probed. Set system clock to %u\n" , i2c->sys_freq); |
226 | |
227 | ret = thunder_i2c_smbus_setup(i2c, node: pdev->dev.of_node); |
228 | if (ret) |
229 | dev_info(dev, "SMBUS alert not active on this bus\n" ); |
230 | |
231 | return 0; |
232 | |
233 | error: |
234 | thunder_i2c_clock_disable(dev, clk: i2c->clk); |
235 | return ret; |
236 | } |
237 | |
238 | static void thunder_i2c_remove_pci(struct pci_dev *pdev) |
239 | { |
240 | struct octeon_i2c *i2c = pci_get_drvdata(pdev); |
241 | |
242 | thunder_i2c_smbus_remove(i2c); |
243 | thunder_i2c_clock_disable(dev: &pdev->dev, clk: i2c->clk); |
244 | i2c_del_adapter(adap: &i2c->adap); |
245 | } |
246 | |
247 | static const struct pci_device_id thunder_i2c_pci_id_table[] = { |
248 | { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_THUNDER_TWSI) }, |
249 | { 0, } |
250 | }; |
251 | |
252 | MODULE_DEVICE_TABLE(pci, thunder_i2c_pci_id_table); |
253 | |
254 | static struct pci_driver thunder_i2c_pci_driver = { |
255 | .name = DRV_NAME, |
256 | .id_table = thunder_i2c_pci_id_table, |
257 | .probe = thunder_i2c_probe_pci, |
258 | .remove = thunder_i2c_remove_pci, |
259 | }; |
260 | |
261 | module_pci_driver(thunder_i2c_pci_driver); |
262 | |
263 | MODULE_LICENSE("GPL" ); |
264 | MODULE_AUTHOR("Fred Martin <fmartin@caviumnetworks.com>" ); |
265 | MODULE_DESCRIPTION("I2C-Bus adapter for Cavium ThunderX SOC" ); |
266 | |