1 files changed, 166 insertions, 71 deletions

diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index c218f73c3650..3e8f126cb7f7 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -34,46 +34,54 @@
  * Also check the comments in the interrupt routines for some gory details.
  */
 
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
-
-#define ICCR1_ICE	0x80
-#define ICCR1_IICRST	0x40
-#define ICCR1_SOWP	0x10
-
-#define ICCR2_BBSY	0x80
-#define ICCR2_SP	0x08
-#define ICCR2_RS	0x04
-#define ICCR2_ST	0x02
-
-#define ICMR1_CKS_MASK	0x70
-#define ICMR1_BCWP	0x08
+#include <linux/time.h>
+
+#define ICCR1_ICE	BIT(7)
+#define ICCR1_IICRST	BIT(6)
+#define ICCR1_SOWP	BIT(4)
+#define ICCR1_SCLO	BIT(3)
+#define ICCR1_SDAO	BIT(2)
+#define ICCR1_SCLI	BIT(1)
+#define ICCR1_SDAI	BIT(0)
+
+#define ICCR2_BBSY	BIT(7)
+#define ICCR2_SP	BIT(3)
+#define ICCR2_RS	BIT(2)
+#define ICCR2_ST	BIT(1)
+
+#define ICMR1_CKS_MASK	GENMASK(6, 4)
+#define ICMR1_BCWP	BIT(3)
 #define ICMR1_CKS(_x)	((((_x) << 4) & ICMR1_CKS_MASK) | ICMR1_BCWP)
 
-#define ICMR3_RDRFS	0x20
-#define ICMR3_ACKWP	0x10
-#define ICMR3_ACKBT	0x08
+#define ICMR3_RDRFS	BIT(5)
+#define ICMR3_ACKWP	BIT(4)
+#define ICMR3_ACKBT	BIT(3)
 
-#define ICFER_FMPE	0x80
+#define ICFER_FMPE	BIT(7)
 
-#define ICIER_TIE	0x80
-#define ICIER_TEIE	0x40
-#define ICIER_RIE	0x20
-#define ICIER_NAKIE	0x10
-#define ICIER_SPIE	0x08
+#define ICIER_TIE	BIT(7)
+#define ICIER_TEIE	BIT(6)
+#define ICIER_RIE	BIT(5)
+#define ICIER_NAKIE	BIT(4)
+#define ICIER_SPIE	BIT(3)
 
-#define ICSR2_NACKF	0x10
+#define ICSR2_NACKF	BIT(4)
+#define ICSR2_STOP	BIT(3)
 
-#define ICBR_RESERVED	0xe0 /* Should be 1 on writes */
+#define ICBR_RESERVED	GENMASK(7, 5) /* Should be 1 on writes */
 
 #define RIIC_INIT_MSG	-1
 
@@ -95,6 +103,8 @@ enum riic_reg_list {
 
 struct riic_of_data {
 	const u8 *regs;
+	const struct riic_irq_desc *irqs;
+	u8 num_irqs;
 	bool fast_mode_plus;
 };
 
@@ -134,6 +144,27 @@ static inline void riic_clear_set_bit(struct riic_dev *riic, u8 clear, u8 set, u
 	riic_writeb(riic, (riic_readb(riic, reg) & ~clear) | set, reg);
 }
 
+static int riic_bus_barrier(struct riic_dev *riic)
+{
+	int ret;
+	u8 val;
+
+	/*
+	 * The SDA line can still be low even when BBSY = 0. Therefore, after checking
+	 * the BBSY flag, also verify that the SDA and SCL lines are not being held low.
+	 */
+	ret = readb_poll_timeout(riic->base + riic->info->regs[RIIC_ICCR2], val,
+				 !(val & ICCR2_BBSY), 10, riic->adapter.timeout);
+	if (ret)
+		return i2c_recover_bus(&riic->adapter);
+
+	if ((riic_readb(riic, RIIC_ICCR1) & (ICCR1_SDAI | ICCR1_SCLI)) !=
+	     (ICCR1_SDAI | ICCR1_SCLI))
+		return i2c_recover_bus(&riic->adapter);
+
+	return 0;
+}
+
 static int riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 {
 	struct riic_dev *riic = i2c_get_adapdata(adap);
@@ -146,13 +177,11 @@ static int riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	if (ret)
 		return ret;
 
-	if (riic_readb(riic, RIIC_ICCR2) & ICCR2_BBSY) {
-		riic->err = -EBUSY;
+	riic->err = riic_bus_barrier(riic);
+	if (riic->err)
 		goto out;
-	}
 
 	reinit_completion(&riic->msg_done);
-	riic->err = 0;
 
 	riic_writeb(riic, 0, RIIC_ICSR2);
 
@@ -177,7 +206,6 @@ static int riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	}
 
  out:
-	pm_runtime_mark_last_busy(dev);
 	pm_runtime_put_autosuspend(dev);
 
 	return riic->err ?: num;
@@ -298,6 +326,19 @@ static irqreturn_t riic_stop_isr(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t riic_eei_isr(int irq, void *data)
+{
+	u8 icsr2 = riic_readb(data, RIIC_ICSR2);
+
+	if (icsr2 & ICSR2_NACKF)
+		return riic_tend_isr(irq, data);
+
+	if (icsr2 & ICSR2_STOP)
+		return riic_stop_isr(irq, data);
+
+	return IRQ_NONE;
+}
+
 static u32 riic_func(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
@@ -312,6 +353,7 @@ static int riic_init_hw(struct riic_dev *riic)
 {
 	int ret;
 	unsigned long rate;
+	unsigned long ns_per_tick;
 	int total_ticks, cks, brl, brh;
 	struct i2c_timings *t = &riic->i2c_t;
 	struct device *dev = riic->adapter.dev.parent;
@@ -320,7 +362,7 @@ static int riic_init_hw(struct riic_dev *riic)
 				      : I2C_MAX_FAST_MODE_FREQ;
 
 	if (t->bus_freq_hz > max_freq)
-		return dev_err_probe(&riic->adapter.dev, -EINVAL,
+		return dev_err_probe(dev, -EINVAL,
 				     "unsupported bus speed %uHz (%u max)\n",
 				     t->bus_freq_hz, max_freq);
 
@@ -343,7 +385,7 @@ static int riic_init_hw(struct riic_dev *riic)
 	 */
 	total_ticks = DIV_ROUND_UP(rate, t->bus_freq_hz ?: 1);
 
-	for (cks = 0; cks < 7; cks++) {
+	for (cks = 0; cks <= 7; cks++) {
 		/*
 		 * 60% low time must be less than BRL + 2 + 1
 		 * BRL max register value is 0x1F.
@@ -352,15 +394,13 @@ static int riic_init_hw(struct riic_dev *riic)
 		if (brl <= (0x1F + 3))
 			break;
 
-		total_ticks /= 2;
+		total_ticks = DIV_ROUND_UP(total_ticks, 2);
 		rate /= 2;
 	}
 
-	if (brl > (0x1F + 3)) {
-		dev_err(&riic->adapter.dev, "invalid speed (%lu). Too slow.\n",
-			(unsigned long)t->bus_freq_hz);
-		return -EINVAL;
-	}
+	if (brl > (0x1F + 3))
+		return dev_err_probe(dev, -EINVAL, "invalid speed (%uHz). Too slow.\n",
+				     t->bus_freq_hz);
 
 	brh = total_ticks - brl;
 
@@ -377,8 +417,9 @@ static int riic_init_hw(struct riic_dev *riic)
 	 * Remove clock ticks for rise and fall times. Convert ns to clock
 	 * ticks.
 	 */
-	brl -= t->scl_fall_ns / (1000000000 / rate);
-	brh -= t->scl_rise_ns / (1000000000 / rate);
+	ns_per_tick = NSEC_PER_SEC / rate;
+	brl -= t->scl_fall_ns / ns_per_tick;
+	brh -= t->scl_rise_ns / ns_per_tick;
 
 	/* Adjust for min register values for when SCLE=1 and NFE=1 */
 	if (brl < 1)
@@ -388,8 +429,7 @@ static int riic_init_hw(struct riic_dev *riic)
 
 	pr_debug("i2c-riic: freq=%lu, duty=%d, fall=%lu, rise=%lu, cks=%d, brl=%d, brh=%d\n",
 		 rate / total_ticks, ((brl + 3) * 100) / (brl + brh + 6),
-		 t->scl_fall_ns / (1000000000 / rate),
-		 t->scl_rise_ns / (1000000000 / rate), cks, brl, brh);
+		 t->scl_fall_ns / ns_per_tick, t->scl_rise_ns / ns_per_tick, cks, brl, brh);
 
 	ret = pm_runtime_resume_and_get(dev);
 	if (ret)
@@ -411,12 +451,57 @@ static int riic_init_hw(struct riic_dev *riic)
 
 	riic_clear_set_bit(riic, ICCR1_IICRST, 0, RIIC_ICCR1);
 
-	pm_runtime_mark_last_busy(dev);
 	pm_runtime_put_autosuspend(dev);
 	return 0;
 }
 
-static struct riic_irq_desc riic_irqs[] = {
+static int riic_get_scl(struct i2c_adapter *adap)
+{
+	struct riic_dev *riic = i2c_get_adapdata(adap);
+
+	return !!(riic_readb(riic, RIIC_ICCR1) & ICCR1_SCLI);
+}
+
+static int riic_get_sda(struct i2c_adapter *adap)
+{
+	struct riic_dev *riic = i2c_get_adapdata(adap);
+
+	return !!(riic_readb(riic, RIIC_ICCR1) & ICCR1_SDAI);
+}
+
+static void riic_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct riic_dev *riic = i2c_get_adapdata(adap);
+
+	if (val)
+		riic_clear_set_bit(riic, ICCR1_SOWP, ICCR1_SCLO, RIIC_ICCR1);
+	else
+		riic_clear_set_bit(riic, ICCR1_SOWP | ICCR1_SCLO, 0, RIIC_ICCR1);
+
+	riic_clear_set_bit(riic, 0, ICCR1_SOWP, RIIC_ICCR1);
+}
+
+static void riic_set_sda(struct i2c_adapter *adap, int val)
+{
+	struct riic_dev *riic = i2c_get_adapdata(adap);
+
+	if (val)
+		riic_clear_set_bit(riic, ICCR1_SOWP, ICCR1_SDAO, RIIC_ICCR1);
+	else
+		riic_clear_set_bit(riic, ICCR1_SOWP | ICCR1_SDAO, 0, RIIC_ICCR1);
+
+	riic_clear_set_bit(riic, 0, ICCR1_SOWP, RIIC_ICCR1);
+}
+
+static struct i2c_bus_recovery_info riic_bri = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.get_scl = riic_get_scl,
+	.set_scl = riic_set_scl,
+	.get_sda = riic_get_sda,
+	.set_sda = riic_set_sda,
+};
+
+static const struct riic_irq_desc riic_irqs[] = {
 	{ .res_num = 0, .isr = riic_tend_isr, .name = "riic-tend" },
 	{ .res_num = 1, .isr = riic_rdrf_isr, .name = "riic-rdrf" },
 	{ .res_num = 2, .isr = riic_tdre_isr, .name = "riic-tdre" },
@@ -424,10 +509,12 @@ static struct riic_irq_desc riic_irqs[] = {
 	{ .res_num = 5, .isr = riic_tend_isr, .name = "riic-nack" },
 };
 
-static void riic_reset_control_assert(void *data)
-{
-	reset_control_assert(data);
-}
+static const struct riic_irq_desc riic_rzt2h_irqs[] = {
+	{ .res_num = 0, .isr = riic_eei_isr,  .name = "riic-eei" },
+	{ .res_num = 1, .isr = riic_rdrf_isr, .name = "riic-rxi" },
+	{ .res_num = 2, .isr = riic_tdre_isr, .name = "riic-txi" },
+	{ .res_num = 3, .isr = riic_tend_isr, .name = "riic-tei" },
+};
 
 static int riic_i2c_probe(struct platform_device *pdev)
 {
@@ -445,38 +532,32 @@ static int riic_i2c_probe(struct platform_device *pdev)
 		return PTR_ERR(riic->base);
 
 	riic->clk = devm_clk_get(dev, NULL);
-	if (IS_ERR(riic->clk)) {
-		dev_err(dev, "missing controller clock");
-		return PTR_ERR(riic->clk);
-	}
+	if (IS_ERR(riic->clk))
+		return dev_err_probe(dev, PTR_ERR(riic->clk),
+				     "missing controller clock");
 
-	riic->rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
+	riic->rstc = devm_reset_control_get_optional_exclusive_deasserted(dev, NULL);
 	if (IS_ERR(riic->rstc))
 		return dev_err_probe(dev, PTR_ERR(riic->rstc),
-				     "Error: missing reset ctrl\n");
+				     "failed to acquire deasserted reset\n");
 
-	ret = reset_control_deassert(riic->rstc);
-	if (ret)
-		return ret;
+	riic->info = of_device_get_match_data(dev);
 
-	ret = devm_add_action_or_reset(dev, riic_reset_control_assert, riic->rstc);
-	if (ret)
-		return ret;
+	for (i = 0; i < riic->info->num_irqs; i++) {
+		const struct riic_irq_desc *irq_desc;
+		int irq;
 
-	for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {
-		ret = platform_get_irq(pdev, riic_irqs[i].res_num);
-		if (ret < 0)
-			return ret;
+		irq_desc = &riic->info->irqs[i];
+		irq = platform_get_irq(pdev, irq_desc->res_num);
+		if (irq < 0)
+			return irq;
 
-		ret = devm_request_irq(dev, ret, riic_irqs[i].isr,
-				       0, riic_irqs[i].name, riic);
-		if (ret) {
-			dev_err(dev, "failed to request irq %s\n", riic_irqs[i].name);
-			return ret;
-		}
+		ret = devm_request_irq(dev, irq, irq_desc->isr, 0, irq_desc->name, riic);
+		if (ret)
+			return dev_err_probe(dev, ret, "failed to request irq %s\n",
+					     irq_desc->name);
 	}
 
-	riic->info = of_device_get_match_data(dev);
 
 	adap = &riic->adapter;
 	i2c_set_adapdata(adap, riic);
@@ -485,6 +566,7 @@ static int riic_i2c_probe(struct platform_device *pdev)
 	adap->algo = &riic_algo;
 	adap->dev.parent = dev;
 	adap->dev.of_node = dev->of_node;
+	adap->bus_recovery_info = &riic_bri;
 
 	init_completion(&riic->msg_done);
 
@@ -547,11 +629,15 @@ static const u8 riic_rz_a_regs[RIIC_REG_END] = {
 
 static const struct riic_of_data riic_rz_a_info = {
 	.regs = riic_rz_a_regs,
+	.irqs = riic_irqs,
+	.num_irqs = ARRAY_SIZE(riic_irqs),
 	.fast_mode_plus = true,
 };
 
 static const struct riic_of_data riic_rz_a1h_info = {
 	.regs = riic_rz_a_regs,
+	.irqs = riic_irqs,
+	.num_irqs = ARRAY_SIZE(riic_irqs),
 };
 
 static const u8 riic_rz_v2h_regs[RIIC_REG_END] = {
@@ -571,9 +657,17 @@ static const u8 riic_rz_v2h_regs[RIIC_REG_END] = {
 
 static const struct riic_of_data riic_rz_v2h_info = {
 	.regs = riic_rz_v2h_regs,
+	.irqs = riic_irqs,
+	.num_irqs = ARRAY_SIZE(riic_irqs),
 	.fast_mode_plus = true,
 };
 
+static const struct riic_of_data riic_rz_t2h_info = {
+	.regs = riic_rz_v2h_regs,
+	.irqs = riic_rzt2h_irqs,
+	.num_irqs = ARRAY_SIZE(riic_rzt2h_irqs),
+};
+
 static int riic_i2c_suspend(struct device *dev)
 {
 	struct riic_dev *riic = dev_get_drvdata(dev);
@@ -624,10 +718,11 @@ static const struct dev_pm_ops riic_i2c_pm_ops = {
 };
 
 static const struct of_device_id riic_i2c_dt_ids[] = {
-	{ .compatible = "renesas,riic-rz", .data = &riic_rz_a_info },
 	{ .compatible = "renesas,riic-r7s72100", .data =  &riic_rz_a1h_info, },
 	{ .compatible = "renesas,riic-r9a09g057", .data = &riic_rz_v2h_info },
-	{ /* Sentinel */ },
+	{ .compatible = "renesas,riic-r9a09g077", .data = &riic_rz_t2h_info },
+	{ .compatible = "renesas,riic-rz", .data = &riic_rz_a_info },
+	{ /* Sentinel */ }
 };
 
 static struct platform_driver riic_i2c_driver = {