xref: /openbmc/linux/drivers/i2c/busses/i2c-qcom-geni.c (revision fac59652993f075d57860769c99045b3ca18780d)
1  // SPDX-License-Identifier: GPL-2.0
2  // Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
3  
4  #include <linux/acpi.h>
5  #include <linux/clk.h>
6  #include <linux/dmaengine.h>
7  #include <linux/dma-mapping.h>
8  #include <linux/dma/qcom-gpi-dma.h>
9  #include <linux/err.h>
10  #include <linux/i2c.h>
11  #include <linux/interrupt.h>
12  #include <linux/io.h>
13  #include <linux/module.h>
14  #include <linux/of.h>
15  #include <linux/platform_device.h>
16  #include <linux/pm_runtime.h>
17  #include <linux/soc/qcom/geni-se.h>
18  #include <linux/spinlock.h>
19  
20  #define SE_I2C_TX_TRANS_LEN		0x26c
21  #define SE_I2C_RX_TRANS_LEN		0x270
22  #define SE_I2C_SCL_COUNTERS		0x278
23  
24  #define SE_I2C_ERR  (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |\
25  			M_GP_IRQ_1_EN | M_GP_IRQ_3_EN | M_GP_IRQ_4_EN)
26  #define SE_I2C_ABORT		BIT(1)
27  
28  /* M_CMD OP codes for I2C */
29  #define I2C_WRITE		0x1
30  #define I2C_READ		0x2
31  #define I2C_WRITE_READ		0x3
32  #define I2C_ADDR_ONLY		0x4
33  #define I2C_BUS_CLEAR		0x6
34  #define I2C_STOP_ON_BUS		0x7
35  /* M_CMD params for I2C */
36  #define PRE_CMD_DELAY		BIT(0)
37  #define TIMESTAMP_BEFORE	BIT(1)
38  #define STOP_STRETCH		BIT(2)
39  #define TIMESTAMP_AFTER		BIT(3)
40  #define POST_COMMAND_DELAY	BIT(4)
41  #define IGNORE_ADD_NACK		BIT(6)
42  #define READ_FINISHED_WITH_ACK	BIT(7)
43  #define BYPASS_ADDR_PHASE	BIT(8)
44  #define SLV_ADDR_MSK		GENMASK(15, 9)
45  #define SLV_ADDR_SHFT		9
46  /* I2C SCL COUNTER fields */
47  #define HIGH_COUNTER_MSK	GENMASK(29, 20)
48  #define HIGH_COUNTER_SHFT	20
49  #define LOW_COUNTER_MSK		GENMASK(19, 10)
50  #define LOW_COUNTER_SHFT	10
51  #define CYCLE_COUNTER_MSK	GENMASK(9, 0)
52  
53  #define I2C_PACK_TX		BIT(0)
54  #define I2C_PACK_RX		BIT(1)
55  
56  enum geni_i2c_err_code {
57  	GP_IRQ0,
58  	NACK,
59  	GP_IRQ2,
60  	BUS_PROTO,
61  	ARB_LOST,
62  	GP_IRQ5,
63  	GENI_OVERRUN,
64  	GENI_ILLEGAL_CMD,
65  	GENI_ABORT_DONE,
66  	GENI_TIMEOUT,
67  };
68  
69  #define DM_I2C_CB_ERR		((BIT(NACK) | BIT(BUS_PROTO) | BIT(ARB_LOST)) \
70  									<< 5)
71  
72  #define I2C_AUTO_SUSPEND_DELAY	250
73  #define KHZ(freq)		(1000 * freq)
74  #define PACKING_BYTES_PW	4
75  
76  #define ABORT_TIMEOUT		HZ
77  #define XFER_TIMEOUT		HZ
78  #define RST_TIMEOUT		HZ
79  
80  struct geni_i2c_dev {
81  	struct geni_se se;
82  	u32 tx_wm;
83  	int irq;
84  	int err;
85  	struct i2c_adapter adap;
86  	struct completion done;
87  	struct i2c_msg *cur;
88  	int cur_wr;
89  	int cur_rd;
90  	spinlock_t lock;
91  	struct clk *core_clk;
92  	u32 clk_freq_out;
93  	const struct geni_i2c_clk_fld *clk_fld;
94  	int suspended;
95  	void *dma_buf;
96  	size_t xfer_len;
97  	dma_addr_t dma_addr;
98  	struct dma_chan *tx_c;
99  	struct dma_chan *rx_c;
100  	bool gpi_mode;
101  	bool abort_done;
102  };
103  
104  struct geni_i2c_desc {
105  	bool has_core_clk;
106  	char *icc_ddr;
107  	bool no_dma_support;
108  	unsigned int tx_fifo_depth;
109  };
110  
111  struct geni_i2c_err_log {
112  	int err;
113  	const char *msg;
114  };
115  
116  static const struct geni_i2c_err_log gi2c_log[] = {
117  	[GP_IRQ0] = {-EIO, "Unknown I2C err GP_IRQ0"},
118  	[NACK] = {-ENXIO, "NACK: slv unresponsive, check its power/reset-ln"},
119  	[GP_IRQ2] = {-EIO, "Unknown I2C err GP IRQ2"},
120  	[BUS_PROTO] = {-EPROTO, "Bus proto err, noisy/unexpected start/stop"},
121  	[ARB_LOST] = {-EAGAIN, "Bus arbitration lost, clock line undriveable"},
122  	[GP_IRQ5] = {-EIO, "Unknown I2C err GP IRQ5"},
123  	[GENI_OVERRUN] = {-EIO, "Cmd overrun, check GENI cmd-state machine"},
124  	[GENI_ILLEGAL_CMD] = {-EIO, "Illegal cmd, check GENI cmd-state machine"},
125  	[GENI_ABORT_DONE] = {-ETIMEDOUT, "Abort after timeout successful"},
126  	[GENI_TIMEOUT] = {-ETIMEDOUT, "I2C TXN timed out"},
127  };
128  
129  struct geni_i2c_clk_fld {
130  	u32	clk_freq_out;
131  	u8	clk_div;
132  	u8	t_high_cnt;
133  	u8	t_low_cnt;
134  	u8	t_cycle_cnt;
135  };
136  
137  /*
138   * Hardware uses the underlying formula to calculate time periods of
139   * SCL clock cycle. Firmware uses some additional cycles excluded from the
140   * below formula and it is confirmed that the time periods are within
141   * specification limits.
142   *
143   * time of high period of SCL: t_high = (t_high_cnt * clk_div) / source_clock
144   * time of low period of SCL: t_low = (t_low_cnt * clk_div) / source_clock
145   * time of full period of SCL: t_cycle = (t_cycle_cnt * clk_div) / source_clock
146   * clk_freq_out = t / t_cycle
147   * source_clock = 19.2 MHz
148   */
149  static const struct geni_i2c_clk_fld geni_i2c_clk_map[] = {
150  	{KHZ(100), 7, 10, 11, 26},
151  	{KHZ(400), 2,  5, 12, 24},
152  	{KHZ(1000), 1, 3,  9, 18},
153  };
154  
geni_i2c_clk_map_idx(struct geni_i2c_dev * gi2c)155  static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
156  {
157  	int i;
158  	const struct geni_i2c_clk_fld *itr = geni_i2c_clk_map;
159  
160  	for (i = 0; i < ARRAY_SIZE(geni_i2c_clk_map); i++, itr++) {
161  		if (itr->clk_freq_out == gi2c->clk_freq_out) {
162  			gi2c->clk_fld = itr;
163  			return 0;
164  		}
165  	}
166  	return -EINVAL;
167  }
168  
qcom_geni_i2c_conf(struct geni_i2c_dev * gi2c)169  static void qcom_geni_i2c_conf(struct geni_i2c_dev *gi2c)
170  {
171  	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
172  	u32 val;
173  
174  	writel_relaxed(0, gi2c->se.base + SE_GENI_CLK_SEL);
175  
176  	val = (itr->clk_div << CLK_DIV_SHFT) | SER_CLK_EN;
177  	writel_relaxed(val, gi2c->se.base + GENI_SER_M_CLK_CFG);
178  
179  	val = itr->t_high_cnt << HIGH_COUNTER_SHFT;
180  	val |= itr->t_low_cnt << LOW_COUNTER_SHFT;
181  	val |= itr->t_cycle_cnt;
182  	writel_relaxed(val, gi2c->se.base + SE_I2C_SCL_COUNTERS);
183  }
184  
geni_i2c_err_misc(struct geni_i2c_dev * gi2c)185  static void geni_i2c_err_misc(struct geni_i2c_dev *gi2c)
186  {
187  	u32 m_cmd = readl_relaxed(gi2c->se.base + SE_GENI_M_CMD0);
188  	u32 m_stat = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
189  	u32 geni_s = readl_relaxed(gi2c->se.base + SE_GENI_STATUS);
190  	u32 geni_ios = readl_relaxed(gi2c->se.base + SE_GENI_IOS);
191  	u32 dma = readl_relaxed(gi2c->se.base + SE_GENI_DMA_MODE_EN);
192  	u32 rx_st, tx_st;
193  
194  	if (dma) {
195  		rx_st = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
196  		tx_st = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
197  	} else {
198  		rx_st = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFO_STATUS);
199  		tx_st = readl_relaxed(gi2c->se.base + SE_GENI_TX_FIFO_STATUS);
200  	}
201  	dev_dbg(gi2c->se.dev, "DMA:%d tx_stat:0x%x, rx_stat:0x%x, irq-stat:0x%x\n",
202  		dma, tx_st, rx_st, m_stat);
203  	dev_dbg(gi2c->se.dev, "m_cmd:0x%x, geni_status:0x%x, geni_ios:0x%x\n",
204  		m_cmd, geni_s, geni_ios);
205  }
206  
geni_i2c_err(struct geni_i2c_dev * gi2c,int err)207  static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
208  {
209  	if (!gi2c->err)
210  		gi2c->err = gi2c_log[err].err;
211  	if (gi2c->cur)
212  		dev_dbg(gi2c->se.dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
213  			gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);
214  
215  	switch (err) {
216  	case GENI_ABORT_DONE:
217  		gi2c->abort_done = true;
218  		break;
219  	case NACK:
220  	case GENI_TIMEOUT:
221  		dev_dbg(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
222  		break;
223  	default:
224  		dev_err(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
225  		geni_i2c_err_misc(gi2c);
226  		break;
227  	}
228  }
229  
geni_i2c_irq(int irq,void * dev)230  static irqreturn_t geni_i2c_irq(int irq, void *dev)
231  {
232  	struct geni_i2c_dev *gi2c = dev;
233  	void __iomem *base = gi2c->se.base;
234  	int j, p;
235  	u32 m_stat;
236  	u32 rx_st;
237  	u32 dm_tx_st;
238  	u32 dm_rx_st;
239  	u32 dma;
240  	u32 val;
241  	struct i2c_msg *cur;
242  
243  	spin_lock(&gi2c->lock);
244  	m_stat = readl_relaxed(base + SE_GENI_M_IRQ_STATUS);
245  	rx_st = readl_relaxed(base + SE_GENI_RX_FIFO_STATUS);
246  	dm_tx_st = readl_relaxed(base + SE_DMA_TX_IRQ_STAT);
247  	dm_rx_st = readl_relaxed(base + SE_DMA_RX_IRQ_STAT);
248  	dma = readl_relaxed(base + SE_GENI_DMA_MODE_EN);
249  	cur = gi2c->cur;
250  
251  	if (!cur ||
252  	    m_stat & (M_CMD_FAILURE_EN | M_CMD_ABORT_EN) ||
253  	    dm_rx_st & (DM_I2C_CB_ERR)) {
254  		if (m_stat & M_GP_IRQ_1_EN)
255  			geni_i2c_err(gi2c, NACK);
256  		if (m_stat & M_GP_IRQ_3_EN)
257  			geni_i2c_err(gi2c, BUS_PROTO);
258  		if (m_stat & M_GP_IRQ_4_EN)
259  			geni_i2c_err(gi2c, ARB_LOST);
260  		if (m_stat & M_CMD_OVERRUN_EN)
261  			geni_i2c_err(gi2c, GENI_OVERRUN);
262  		if (m_stat & M_ILLEGAL_CMD_EN)
263  			geni_i2c_err(gi2c, GENI_ILLEGAL_CMD);
264  		if (m_stat & M_CMD_ABORT_EN)
265  			geni_i2c_err(gi2c, GENI_ABORT_DONE);
266  		if (m_stat & M_GP_IRQ_0_EN)
267  			geni_i2c_err(gi2c, GP_IRQ0);
268  
269  		/* Disable the TX Watermark interrupt to stop TX */
270  		if (!dma)
271  			writel_relaxed(0, base + SE_GENI_TX_WATERMARK_REG);
272  	} else if (dma) {
273  		dev_dbg(gi2c->se.dev, "i2c dma tx:0x%x, dma rx:0x%x\n",
274  			dm_tx_st, dm_rx_st);
275  	} else if (cur->flags & I2C_M_RD &&
276  		   m_stat & (M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN)) {
277  		u32 rxcnt = rx_st & RX_FIFO_WC_MSK;
278  
279  		for (j = 0; j < rxcnt; j++) {
280  			p = 0;
281  			val = readl_relaxed(base + SE_GENI_RX_FIFOn);
282  			while (gi2c->cur_rd < cur->len && p < sizeof(val)) {
283  				cur->buf[gi2c->cur_rd++] = val & 0xff;
284  				val >>= 8;
285  				p++;
286  			}
287  			if (gi2c->cur_rd == cur->len)
288  				break;
289  		}
290  	} else if (!(cur->flags & I2C_M_RD) &&
291  		   m_stat & M_TX_FIFO_WATERMARK_EN) {
292  		for (j = 0; j < gi2c->tx_wm; j++) {
293  			u32 temp;
294  
295  			val = 0;
296  			p = 0;
297  			while (gi2c->cur_wr < cur->len && p < sizeof(val)) {
298  				temp = cur->buf[gi2c->cur_wr++];
299  				val |= temp << (p * 8);
300  				p++;
301  			}
302  			writel_relaxed(val, base + SE_GENI_TX_FIFOn);
303  			/* TX Complete, Disable the TX Watermark interrupt */
304  			if (gi2c->cur_wr == cur->len) {
305  				writel_relaxed(0, base + SE_GENI_TX_WATERMARK_REG);
306  				break;
307  			}
308  		}
309  	}
310  
311  	if (m_stat)
312  		writel_relaxed(m_stat, base + SE_GENI_M_IRQ_CLEAR);
313  
314  	if (dma && dm_tx_st)
315  		writel_relaxed(dm_tx_st, base + SE_DMA_TX_IRQ_CLR);
316  	if (dma && dm_rx_st)
317  		writel_relaxed(dm_rx_st, base + SE_DMA_RX_IRQ_CLR);
318  
319  	/* if this is err with done-bit not set, handle that through timeout. */
320  	if (m_stat & M_CMD_DONE_EN || m_stat & M_CMD_ABORT_EN ||
321  	    dm_tx_st & TX_DMA_DONE || dm_tx_st & TX_RESET_DONE ||
322  	    dm_rx_st & RX_DMA_DONE || dm_rx_st & RX_RESET_DONE)
323  		complete(&gi2c->done);
324  
325  	spin_unlock(&gi2c->lock);
326  
327  	return IRQ_HANDLED;
328  }
329  
geni_i2c_abort_xfer(struct geni_i2c_dev * gi2c)330  static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
331  {
332  	unsigned long time_left = ABORT_TIMEOUT;
333  	unsigned long flags;
334  
335  	spin_lock_irqsave(&gi2c->lock, flags);
336  	geni_i2c_err(gi2c, GENI_TIMEOUT);
337  	gi2c->cur = NULL;
338  	gi2c->abort_done = false;
339  	geni_se_abort_m_cmd(&gi2c->se);
340  	spin_unlock_irqrestore(&gi2c->lock, flags);
341  
342  	do {
343  		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
344  	} while (!gi2c->abort_done && time_left);
345  
346  	if (!time_left)
347  		dev_err(gi2c->se.dev, "Timeout abort_m_cmd\n");
348  }
349  
geni_i2c_rx_fsm_rst(struct geni_i2c_dev * gi2c)350  static void geni_i2c_rx_fsm_rst(struct geni_i2c_dev *gi2c)
351  {
352  	u32 val;
353  	unsigned long time_left = RST_TIMEOUT;
354  
355  	writel_relaxed(1, gi2c->se.base + SE_DMA_RX_FSM_RST);
356  	do {
357  		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
358  		val = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
359  	} while (!(val & RX_RESET_DONE) && time_left);
360  
361  	if (!(val & RX_RESET_DONE))
362  		dev_err(gi2c->se.dev, "Timeout resetting RX_FSM\n");
363  }
364  
geni_i2c_tx_fsm_rst(struct geni_i2c_dev * gi2c)365  static void geni_i2c_tx_fsm_rst(struct geni_i2c_dev *gi2c)
366  {
367  	u32 val;
368  	unsigned long time_left = RST_TIMEOUT;
369  
370  	writel_relaxed(1, gi2c->se.base + SE_DMA_TX_FSM_RST);
371  	do {
372  		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
373  		val = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
374  	} while (!(val & TX_RESET_DONE) && time_left);
375  
376  	if (!(val & TX_RESET_DONE))
377  		dev_err(gi2c->se.dev, "Timeout resetting TX_FSM\n");
378  }
379  
geni_i2c_rx_msg_cleanup(struct geni_i2c_dev * gi2c,struct i2c_msg * cur)380  static void geni_i2c_rx_msg_cleanup(struct geni_i2c_dev *gi2c,
381  				     struct i2c_msg *cur)
382  {
383  	gi2c->cur_rd = 0;
384  	if (gi2c->dma_buf) {
385  		if (gi2c->err)
386  			geni_i2c_rx_fsm_rst(gi2c);
387  		geni_se_rx_dma_unprep(&gi2c->se, gi2c->dma_addr, gi2c->xfer_len);
388  		i2c_put_dma_safe_msg_buf(gi2c->dma_buf, cur, !gi2c->err);
389  	}
390  }
391  
geni_i2c_tx_msg_cleanup(struct geni_i2c_dev * gi2c,struct i2c_msg * cur)392  static void geni_i2c_tx_msg_cleanup(struct geni_i2c_dev *gi2c,
393  				     struct i2c_msg *cur)
394  {
395  	gi2c->cur_wr = 0;
396  	if (gi2c->dma_buf) {
397  		if (gi2c->err)
398  			geni_i2c_tx_fsm_rst(gi2c);
399  		geni_se_tx_dma_unprep(&gi2c->se, gi2c->dma_addr, gi2c->xfer_len);
400  		i2c_put_dma_safe_msg_buf(gi2c->dma_buf, cur, !gi2c->err);
401  	}
402  }
403  
geni_i2c_rx_one_msg(struct geni_i2c_dev * gi2c,struct i2c_msg * msg,u32 m_param)404  static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
405  				u32 m_param)
406  {
407  	dma_addr_t rx_dma = 0;
408  	unsigned long time_left;
409  	void *dma_buf;
410  	struct geni_se *se = &gi2c->se;
411  	size_t len = msg->len;
412  	struct i2c_msg *cur;
413  
414  	dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
415  	if (dma_buf)
416  		geni_se_select_mode(se, GENI_SE_DMA);
417  	else
418  		geni_se_select_mode(se, GENI_SE_FIFO);
419  
420  	writel_relaxed(len, se->base + SE_I2C_RX_TRANS_LEN);
421  	geni_se_setup_m_cmd(se, I2C_READ, m_param);
422  
423  	if (dma_buf && geni_se_rx_dma_prep(se, dma_buf, len, &rx_dma)) {
424  		geni_se_select_mode(se, GENI_SE_FIFO);
425  		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
426  		dma_buf = NULL;
427  	} else {
428  		gi2c->xfer_len = len;
429  		gi2c->dma_addr = rx_dma;
430  		gi2c->dma_buf = dma_buf;
431  	}
432  
433  	cur = gi2c->cur;
434  	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
435  	if (!time_left)
436  		geni_i2c_abort_xfer(gi2c);
437  
438  	geni_i2c_rx_msg_cleanup(gi2c, cur);
439  
440  	return gi2c->err;
441  }
442  
geni_i2c_tx_one_msg(struct geni_i2c_dev * gi2c,struct i2c_msg * msg,u32 m_param)443  static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
444  				u32 m_param)
445  {
446  	dma_addr_t tx_dma = 0;
447  	unsigned long time_left;
448  	void *dma_buf;
449  	struct geni_se *se = &gi2c->se;
450  	size_t len = msg->len;
451  	struct i2c_msg *cur;
452  
453  	dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
454  	if (dma_buf)
455  		geni_se_select_mode(se, GENI_SE_DMA);
456  	else
457  		geni_se_select_mode(se, GENI_SE_FIFO);
458  
459  	writel_relaxed(len, se->base + SE_I2C_TX_TRANS_LEN);
460  	geni_se_setup_m_cmd(se, I2C_WRITE, m_param);
461  
462  	if (dma_buf && geni_se_tx_dma_prep(se, dma_buf, len, &tx_dma)) {
463  		geni_se_select_mode(se, GENI_SE_FIFO);
464  		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
465  		dma_buf = NULL;
466  	} else {
467  		gi2c->xfer_len = len;
468  		gi2c->dma_addr = tx_dma;
469  		gi2c->dma_buf = dma_buf;
470  	}
471  
472  	if (!dma_buf) /* Get FIFO IRQ */
473  		writel_relaxed(1, se->base + SE_GENI_TX_WATERMARK_REG);
474  
475  	cur = gi2c->cur;
476  	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
477  	if (!time_left)
478  		geni_i2c_abort_xfer(gi2c);
479  
480  	geni_i2c_tx_msg_cleanup(gi2c, cur);
481  
482  	return gi2c->err;
483  }
484  
i2c_gpi_cb_result(void * cb,const struct dmaengine_result * result)485  static void i2c_gpi_cb_result(void *cb, const struct dmaengine_result *result)
486  {
487  	struct geni_i2c_dev *gi2c = cb;
488  
489  	if (result->result != DMA_TRANS_NOERROR) {
490  		dev_err(gi2c->se.dev, "DMA txn failed:%d\n", result->result);
491  		gi2c->err = -EIO;
492  	} else if (result->residue) {
493  		dev_dbg(gi2c->se.dev, "DMA xfer has pending: %d\n", result->residue);
494  	}
495  
496  	complete(&gi2c->done);
497  }
498  
geni_i2c_gpi_unmap(struct geni_i2c_dev * gi2c,struct i2c_msg * msg,void * tx_buf,dma_addr_t tx_addr,void * rx_buf,dma_addr_t rx_addr)499  static void geni_i2c_gpi_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
500  			       void *tx_buf, dma_addr_t tx_addr,
501  			       void *rx_buf, dma_addr_t rx_addr)
502  {
503  	if (tx_buf) {
504  		dma_unmap_single(gi2c->se.dev->parent, tx_addr, msg->len, DMA_TO_DEVICE);
505  		i2c_put_dma_safe_msg_buf(tx_buf, msg, !gi2c->err);
506  	}
507  
508  	if (rx_buf) {
509  		dma_unmap_single(gi2c->se.dev->parent, rx_addr, msg->len, DMA_FROM_DEVICE);
510  		i2c_put_dma_safe_msg_buf(rx_buf, msg, !gi2c->err);
511  	}
512  }
513  
geni_i2c_gpi(struct geni_i2c_dev * gi2c,struct i2c_msg * msg,struct dma_slave_config * config,dma_addr_t * dma_addr_p,void ** buf,unsigned int op,struct dma_chan * dma_chan)514  static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
515  			struct dma_slave_config *config, dma_addr_t *dma_addr_p,
516  			void **buf, unsigned int op, struct dma_chan *dma_chan)
517  {
518  	struct gpi_i2c_config *peripheral;
519  	unsigned int flags;
520  	void *dma_buf;
521  	dma_addr_t addr;
522  	enum dma_data_direction map_dirn;
523  	enum dma_transfer_direction dma_dirn;
524  	struct dma_async_tx_descriptor *desc;
525  	int ret;
526  
527  	peripheral = config->peripheral_config;
528  
529  	dma_buf = i2c_get_dma_safe_msg_buf(msg, 1);
530  	if (!dma_buf)
531  		return -ENOMEM;
532  
533  	if (op == I2C_WRITE)
534  		map_dirn = DMA_TO_DEVICE;
535  	else
536  		map_dirn = DMA_FROM_DEVICE;
537  
538  	addr = dma_map_single(gi2c->se.dev->parent, dma_buf, msg->len, map_dirn);
539  	if (dma_mapping_error(gi2c->se.dev->parent, addr)) {
540  		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
541  		return -ENOMEM;
542  	}
543  
544  	/* set the length as message for rx txn */
545  	peripheral->rx_len = msg->len;
546  	peripheral->op = op;
547  
548  	ret = dmaengine_slave_config(dma_chan, config);
549  	if (ret) {
550  		dev_err(gi2c->se.dev, "dma config error: %d for op:%d\n", ret, op);
551  		goto err_config;
552  	}
553  
554  	peripheral->set_config = 0;
555  	peripheral->multi_msg = true;
556  	flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
557  
558  	if (op == I2C_WRITE)
559  		dma_dirn = DMA_MEM_TO_DEV;
560  	else
561  		dma_dirn = DMA_DEV_TO_MEM;
562  
563  	desc = dmaengine_prep_slave_single(dma_chan, addr, msg->len, dma_dirn, flags);
564  	if (!desc) {
565  		dev_err(gi2c->se.dev, "prep_slave_sg failed\n");
566  		ret = -EIO;
567  		goto err_config;
568  	}
569  
570  	desc->callback_result = i2c_gpi_cb_result;
571  	desc->callback_param = gi2c;
572  
573  	dmaengine_submit(desc);
574  	*buf = dma_buf;
575  	*dma_addr_p = addr;
576  
577  	return 0;
578  
579  err_config:
580  	dma_unmap_single(gi2c->se.dev->parent, addr, msg->len, map_dirn);
581  	i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
582  	return ret;
583  }
584  
geni_i2c_gpi_xfer(struct geni_i2c_dev * gi2c,struct i2c_msg msgs[],int num)585  static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], int num)
586  {
587  	struct dma_slave_config config = {};
588  	struct gpi_i2c_config peripheral = {};
589  	int i, ret = 0, timeout;
590  	dma_addr_t tx_addr, rx_addr;
591  	void *tx_buf = NULL, *rx_buf = NULL;
592  	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
593  
594  	config.peripheral_config = &peripheral;
595  	config.peripheral_size = sizeof(peripheral);
596  
597  	peripheral.pack_enable = I2C_PACK_TX | I2C_PACK_RX;
598  	peripheral.cycle_count = itr->t_cycle_cnt;
599  	peripheral.high_count = itr->t_high_cnt;
600  	peripheral.low_count = itr->t_low_cnt;
601  	peripheral.clk_div = itr->clk_div;
602  	peripheral.set_config = 1;
603  	peripheral.multi_msg = false;
604  
605  	for (i = 0; i < num; i++) {
606  		gi2c->cur = &msgs[i];
607  		gi2c->err = 0;
608  		dev_dbg(gi2c->se.dev, "msg[%d].len:%d\n", i, gi2c->cur->len);
609  
610  		peripheral.stretch = 0;
611  		if (i < num - 1)
612  			peripheral.stretch = 1;
613  
614  		peripheral.addr = msgs[i].addr;
615  
616  		ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
617  				    &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
618  		if (ret)
619  			goto err;
620  
621  		if (msgs[i].flags & I2C_M_RD) {
622  			ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
623  					    &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c);
624  			if (ret)
625  				goto err;
626  
627  			dma_async_issue_pending(gi2c->rx_c);
628  		}
629  
630  		dma_async_issue_pending(gi2c->tx_c);
631  
632  		timeout = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
633  		if (!timeout) {
634  			dev_err(gi2c->se.dev, "I2C timeout gpi flags:%d addr:0x%x\n",
635  				gi2c->cur->flags, gi2c->cur->addr);
636  			gi2c->err = -ETIMEDOUT;
637  		}
638  
639  		if (gi2c->err) {
640  			ret = gi2c->err;
641  			goto err;
642  		}
643  
644  		geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
645  	}
646  
647  	return num;
648  
649  err:
650  	dev_err(gi2c->se.dev, "GPI transfer failed: %d\n", ret);
651  	dmaengine_terminate_sync(gi2c->rx_c);
652  	dmaengine_terminate_sync(gi2c->tx_c);
653  	geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
654  	return ret;
655  }
656  
geni_i2c_fifo_xfer(struct geni_i2c_dev * gi2c,struct i2c_msg msgs[],int num)657  static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
658  			      struct i2c_msg msgs[], int num)
659  {
660  	int i, ret = 0;
661  
662  	for (i = 0; i < num; i++) {
663  		u32 m_param = i < (num - 1) ? STOP_STRETCH : 0;
664  
665  		m_param |= ((msgs[i].addr << SLV_ADDR_SHFT) & SLV_ADDR_MSK);
666  
667  		gi2c->cur = &msgs[i];
668  		if (msgs[i].flags & I2C_M_RD)
669  			ret = geni_i2c_rx_one_msg(gi2c, &msgs[i], m_param);
670  		else
671  			ret = geni_i2c_tx_one_msg(gi2c, &msgs[i], m_param);
672  
673  		if (ret)
674  			return ret;
675  	}
676  
677  	return num;
678  }
679  
geni_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)680  static int geni_i2c_xfer(struct i2c_adapter *adap,
681  			 struct i2c_msg msgs[],
682  			 int num)
683  {
684  	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
685  	int ret;
686  
687  	gi2c->err = 0;
688  	reinit_completion(&gi2c->done);
689  	ret = pm_runtime_get_sync(gi2c->se.dev);
690  	if (ret < 0) {
691  		dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
692  		pm_runtime_put_noidle(gi2c->se.dev);
693  		/* Set device in suspended since resume failed */
694  		pm_runtime_set_suspended(gi2c->se.dev);
695  		return ret;
696  	}
697  
698  	qcom_geni_i2c_conf(gi2c);
699  
700  	if (gi2c->gpi_mode)
701  		ret = geni_i2c_gpi_xfer(gi2c, msgs, num);
702  	else
703  		ret = geni_i2c_fifo_xfer(gi2c, msgs, num);
704  
705  	pm_runtime_mark_last_busy(gi2c->se.dev);
706  	pm_runtime_put_autosuspend(gi2c->se.dev);
707  	gi2c->cur = NULL;
708  	gi2c->err = 0;
709  	return ret;
710  }
711  
geni_i2c_func(struct i2c_adapter * adap)712  static u32 geni_i2c_func(struct i2c_adapter *adap)
713  {
714  	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
715  }
716  
717  static const struct i2c_algorithm geni_i2c_algo = {
718  	.master_xfer	= geni_i2c_xfer,
719  	.functionality	= geni_i2c_func,
720  };
721  
722  #ifdef CONFIG_ACPI
723  static const struct acpi_device_id geni_i2c_acpi_match[] = {
724  	{ "QCOM0220"},
725  	{ },
726  };
727  MODULE_DEVICE_TABLE(acpi, geni_i2c_acpi_match);
728  #endif
729  
release_gpi_dma(struct geni_i2c_dev * gi2c)730  static void release_gpi_dma(struct geni_i2c_dev *gi2c)
731  {
732  	if (gi2c->rx_c)
733  		dma_release_channel(gi2c->rx_c);
734  
735  	if (gi2c->tx_c)
736  		dma_release_channel(gi2c->tx_c);
737  }
738  
setup_gpi_dma(struct geni_i2c_dev * gi2c)739  static int setup_gpi_dma(struct geni_i2c_dev *gi2c)
740  {
741  	int ret;
742  
743  	geni_se_select_mode(&gi2c->se, GENI_GPI_DMA);
744  	gi2c->tx_c = dma_request_chan(gi2c->se.dev, "tx");
745  	if (IS_ERR(gi2c->tx_c)) {
746  		ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->tx_c),
747  				    "Failed to get tx DMA ch\n");
748  		goto err_tx;
749  	}
750  
751  	gi2c->rx_c = dma_request_chan(gi2c->se.dev, "rx");
752  	if (IS_ERR(gi2c->rx_c)) {
753  		ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->rx_c),
754  				    "Failed to get rx DMA ch\n");
755  		goto err_rx;
756  	}
757  
758  	dev_dbg(gi2c->se.dev, "Grabbed GPI dma channels\n");
759  	return 0;
760  
761  err_rx:
762  	dma_release_channel(gi2c->tx_c);
763  err_tx:
764  	return ret;
765  }
766  
geni_i2c_probe(struct platform_device * pdev)767  static int geni_i2c_probe(struct platform_device *pdev)
768  {
769  	struct geni_i2c_dev *gi2c;
770  	u32 proto, tx_depth, fifo_disable;
771  	int ret;
772  	struct device *dev = &pdev->dev;
773  	const struct geni_i2c_desc *desc = NULL;
774  
775  	gi2c = devm_kzalloc(dev, sizeof(*gi2c), GFP_KERNEL);
776  	if (!gi2c)
777  		return -ENOMEM;
778  
779  	gi2c->se.dev = dev;
780  	gi2c->se.wrapper = dev_get_drvdata(dev->parent);
781  	gi2c->se.base = devm_platform_ioremap_resource(pdev, 0);
782  	if (IS_ERR(gi2c->se.base))
783  		return PTR_ERR(gi2c->se.base);
784  
785  	desc = device_get_match_data(&pdev->dev);
786  
787  	if (desc && desc->has_core_clk) {
788  		gi2c->core_clk = devm_clk_get(dev, "core");
789  		if (IS_ERR(gi2c->core_clk))
790  			return PTR_ERR(gi2c->core_clk);
791  	}
792  
793  	gi2c->se.clk = devm_clk_get(dev, "se");
794  	if (IS_ERR(gi2c->se.clk) && !has_acpi_companion(dev))
795  		return PTR_ERR(gi2c->se.clk);
796  
797  	ret = device_property_read_u32(dev, "clock-frequency",
798  				       &gi2c->clk_freq_out);
799  	if (ret) {
800  		dev_info(dev, "Bus frequency not specified, default to 100kHz.\n");
801  		gi2c->clk_freq_out = KHZ(100);
802  	}
803  
804  	if (has_acpi_companion(dev))
805  		ACPI_COMPANION_SET(&gi2c->adap.dev, ACPI_COMPANION(dev));
806  
807  	gi2c->irq = platform_get_irq(pdev, 0);
808  	if (gi2c->irq < 0)
809  		return gi2c->irq;
810  
811  	ret = geni_i2c_clk_map_idx(gi2c);
812  	if (ret) {
813  		dev_err(dev, "Invalid clk frequency %d Hz: %d\n",
814  			gi2c->clk_freq_out, ret);
815  		return ret;
816  	}
817  
818  	gi2c->adap.algo = &geni_i2c_algo;
819  	init_completion(&gi2c->done);
820  	spin_lock_init(&gi2c->lock);
821  	platform_set_drvdata(pdev, gi2c);
822  	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, IRQF_NO_AUTOEN,
823  			       dev_name(dev), gi2c);
824  	if (ret) {
825  		dev_err(dev, "Request_irq failed:%d: err:%d\n",
826  			gi2c->irq, ret);
827  		return ret;
828  	}
829  	i2c_set_adapdata(&gi2c->adap, gi2c);
830  	gi2c->adap.dev.parent = dev;
831  	gi2c->adap.dev.of_node = dev->of_node;
832  	strscpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));
833  
834  	ret = geni_icc_get(&gi2c->se, desc ? desc->icc_ddr : "qup-memory");
835  	if (ret)
836  		return ret;
837  	/*
838  	 * Set the bus quota for core and cpu to a reasonable value for
839  	 * register access.
840  	 * Set quota for DDR based on bus speed.
841  	 */
842  	gi2c->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
843  	gi2c->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
844  	if (!desc || desc->icc_ddr)
845  		gi2c->se.icc_paths[GENI_TO_DDR].avg_bw = Bps_to_icc(gi2c->clk_freq_out);
846  
847  	ret = geni_icc_set_bw(&gi2c->se);
848  	if (ret)
849  		return ret;
850  
851  	ret = clk_prepare_enable(gi2c->core_clk);
852  	if (ret)
853  		return ret;
854  
855  	ret = geni_se_resources_on(&gi2c->se);
856  	if (ret) {
857  		dev_err(dev, "Error turning on resources %d\n", ret);
858  		clk_disable_unprepare(gi2c->core_clk);
859  		return ret;
860  	}
861  	proto = geni_se_read_proto(&gi2c->se);
862  	if (proto != GENI_SE_I2C) {
863  		dev_err(dev, "Invalid proto %d\n", proto);
864  		geni_se_resources_off(&gi2c->se);
865  		clk_disable_unprepare(gi2c->core_clk);
866  		return -ENXIO;
867  	}
868  
869  	if (desc && desc->no_dma_support)
870  		fifo_disable = false;
871  	else
872  		fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
873  
874  	if (fifo_disable) {
875  		/* FIFO is disabled, so we can only use GPI DMA */
876  		gi2c->gpi_mode = true;
877  		ret = setup_gpi_dma(gi2c);
878  		if (ret) {
879  			geni_se_resources_off(&gi2c->se);
880  			clk_disable_unprepare(gi2c->core_clk);
881  			return dev_err_probe(dev, ret, "Failed to setup GPI DMA mode\n");
882  		}
883  
884  		dev_dbg(dev, "Using GPI DMA mode for I2C\n");
885  	} else {
886  		gi2c->gpi_mode = false;
887  		tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
888  
889  		/* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */
890  		if (!tx_depth && desc)
891  			tx_depth = desc->tx_fifo_depth;
892  
893  		if (!tx_depth) {
894  			dev_err(dev, "Invalid TX FIFO depth\n");
895  			geni_se_resources_off(&gi2c->se);
896  			clk_disable_unprepare(gi2c->core_clk);
897  			return -EINVAL;
898  		}
899  
900  		gi2c->tx_wm = tx_depth - 1;
901  		geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
902  		geni_se_config_packing(&gi2c->se, BITS_PER_BYTE,
903  				       PACKING_BYTES_PW, true, true, true);
904  
905  		dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
906  	}
907  
908  	clk_disable_unprepare(gi2c->core_clk);
909  	ret = geni_se_resources_off(&gi2c->se);
910  	if (ret) {
911  		dev_err(dev, "Error turning off resources %d\n", ret);
912  		goto err_dma;
913  	}
914  
915  	ret = geni_icc_disable(&gi2c->se);
916  	if (ret)
917  		goto err_dma;
918  
919  	gi2c->suspended = 1;
920  	pm_runtime_set_suspended(gi2c->se.dev);
921  	pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
922  	pm_runtime_use_autosuspend(gi2c->se.dev);
923  	pm_runtime_enable(gi2c->se.dev);
924  
925  	ret = i2c_add_adapter(&gi2c->adap);
926  	if (ret) {
927  		dev_err(dev, "Error adding i2c adapter %d\n", ret);
928  		pm_runtime_disable(gi2c->se.dev);
929  		goto err_dma;
930  	}
931  
932  	dev_dbg(dev, "Geni-I2C adaptor successfully added\n");
933  
934  	return 0;
935  
936  err_dma:
937  	release_gpi_dma(gi2c);
938  	return ret;
939  }
940  
geni_i2c_remove(struct platform_device * pdev)941  static void geni_i2c_remove(struct platform_device *pdev)
942  {
943  	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
944  
945  	i2c_del_adapter(&gi2c->adap);
946  	release_gpi_dma(gi2c);
947  	pm_runtime_disable(gi2c->se.dev);
948  }
949  
geni_i2c_shutdown(struct platform_device * pdev)950  static void geni_i2c_shutdown(struct platform_device *pdev)
951  {
952  	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
953  
954  	/* Make client i2c transfers start failing */
955  	i2c_mark_adapter_suspended(&gi2c->adap);
956  }
957  
geni_i2c_runtime_suspend(struct device * dev)958  static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
959  {
960  	int ret;
961  	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
962  
963  	disable_irq(gi2c->irq);
964  	ret = geni_se_resources_off(&gi2c->se);
965  	if (ret) {
966  		enable_irq(gi2c->irq);
967  		return ret;
968  
969  	} else {
970  		gi2c->suspended = 1;
971  	}
972  
973  	clk_disable_unprepare(gi2c->core_clk);
974  
975  	return geni_icc_disable(&gi2c->se);
976  }
977  
geni_i2c_runtime_resume(struct device * dev)978  static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
979  {
980  	int ret;
981  	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
982  
983  	ret = geni_icc_enable(&gi2c->se);
984  	if (ret)
985  		return ret;
986  
987  	ret = clk_prepare_enable(gi2c->core_clk);
988  	if (ret) {
989  		geni_icc_disable(&gi2c->se);
990  		return ret;
991  	}
992  
993  	ret = geni_se_resources_on(&gi2c->se);
994  	if (ret) {
995  		clk_disable_unprepare(gi2c->core_clk);
996  		geni_icc_disable(&gi2c->se);
997  		return ret;
998  	}
999  
1000  	enable_irq(gi2c->irq);
1001  	gi2c->suspended = 0;
1002  	return 0;
1003  }
1004  
geni_i2c_suspend_noirq(struct device * dev)1005  static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
1006  {
1007  	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
1008  
1009  	i2c_mark_adapter_suspended(&gi2c->adap);
1010  
1011  	if (!gi2c->suspended) {
1012  		geni_i2c_runtime_suspend(dev);
1013  		pm_runtime_disable(dev);
1014  		pm_runtime_set_suspended(dev);
1015  		pm_runtime_enable(dev);
1016  	}
1017  	return 0;
1018  }
1019  
geni_i2c_resume_noirq(struct device * dev)1020  static int __maybe_unused geni_i2c_resume_noirq(struct device *dev)
1021  {
1022  	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
1023  
1024  	i2c_mark_adapter_resumed(&gi2c->adap);
1025  	return 0;
1026  }
1027  
1028  static const struct dev_pm_ops geni_i2c_pm_ops = {
1029  	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(geni_i2c_suspend_noirq, geni_i2c_resume_noirq)
1030  	SET_RUNTIME_PM_OPS(geni_i2c_runtime_suspend, geni_i2c_runtime_resume,
1031  									NULL)
1032  };
1033  
1034  static const struct geni_i2c_desc i2c_master_hub = {
1035  	.has_core_clk = true,
1036  	.icc_ddr = NULL,
1037  	.no_dma_support = true,
1038  	.tx_fifo_depth = 16,
1039  };
1040  
1041  static const struct of_device_id geni_i2c_dt_match[] = {
1042  	{ .compatible = "qcom,geni-i2c" },
1043  	{ .compatible = "qcom,geni-i2c-master-hub", .data = &i2c_master_hub },
1044  	{}
1045  };
1046  MODULE_DEVICE_TABLE(of, geni_i2c_dt_match);
1047  
1048  static struct platform_driver geni_i2c_driver = {
1049  	.probe  = geni_i2c_probe,
1050  	.remove_new = geni_i2c_remove,
1051  	.shutdown = geni_i2c_shutdown,
1052  	.driver = {
1053  		.name = "geni_i2c",
1054  		.pm = &geni_i2c_pm_ops,
1055  		.of_match_table = geni_i2c_dt_match,
1056  		.acpi_match_table = ACPI_PTR(geni_i2c_acpi_match),
1057  	},
1058  };
1059  
1060  module_platform_driver(geni_i2c_driver);
1061  
1062  MODULE_DESCRIPTION("I2C Controller Driver for GENI based QUP cores");
1063  MODULE_LICENSE("GPL v2");
1064