1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2023 Code Construct
4  *
5  * Author: Jeremy Kerr <jk@codeconstruct.com.au>
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/i3c/master.h>
10 #include <linux/reset.h>
11 #include <linux/types.h>
12 
13 #define DW_I3C_MAX_DEVS 32
14 
15 struct dw_i3c_master_caps {
16 	u8 cmdfifodepth;
17 	u8 datafifodepth;
18 };
19 
20 struct dw_i3c_dat_entry {
21 	u8 addr;
22 	struct i3c_dev_desc *ibi_dev;
23 };
24 
25 struct dw_i3c_master {
26 	struct i3c_master_controller base;
27 	u16 maxdevs;
28 	u16 datstartaddr;
29 	u32 free_pos;
30 	struct {
31 		struct list_head list;
32 		struct dw_i3c_xfer *cur;
33 		spinlock_t lock;
34 	} xferqueue;
35 	struct dw_i3c_master_caps caps;
36 	void __iomem *regs;
37 	struct reset_control *core_rst;
38 	struct clk *core_clk;
39 	char version[5];
40 	char type[5];
41 	bool ibi_capable;
42 
43 	/*
44 	 * Per-device hardware data, used to manage the device address table
45 	 * (DAT)
46 	 *
47 	 * Locking: the devs array may be referenced in IRQ context while
48 	 * processing an IBI. However, IBIs (for a specific device, which
49 	 * implies a specific DAT entry) can only happen while interrupts are
50 	 * requested for that device, which is serialised against other
51 	 * insertions/removals from the array by the global i3c infrastructure.
52 	 * So, devs_lock protects against concurrent updates to devs->ibi_dev
53 	 * between request_ibi/free_ibi and the IBI irq event.
54 	 */
55 	struct dw_i3c_dat_entry devs[DW_I3C_MAX_DEVS];
56 	spinlock_t devs_lock;
57 
58 	/* platform-specific data */
59 	const struct dw_i3c_platform_ops *platform_ops;
60 };
61 
62 struct dw_i3c_platform_ops {
63 	/*
64 	 * Called on early bus init: the i3c has been set up, but before any
65 	 * transactions have taken place. Platform implementations may use to
66 	 * perform actual device enabling with the i3c core ready.
67 	 */
68 	int (*init)(struct dw_i3c_master *i3c);
69 
70 	/*
71 	 * Initialise a DAT entry to enable/disable IBIs. Allows the platform
72 	 * to perform any device workarounds on the DAT entry before
73 	 * inserting into the hardware table.
74 	 *
75 	 * Called with the DAT lock held; must not sleep.
76 	 */
77 	void (*set_dat_ibi)(struct dw_i3c_master *i3c,
78 			    struct i3c_dev_desc *dev, bool enable, u32 *reg);
79 };
80 
81 extern int dw_i3c_common_probe(struct dw_i3c_master *master,
82 			       struct platform_device *pdev);
83 extern void dw_i3c_common_remove(struct dw_i3c_master *master);
84 
85