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path: root/drivers/i2c/busses/i2c-riic.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-riic.c')
-rw-r--r--drivers/i2c/busses/i2c-riic.c134
1 files changed, 72 insertions, 62 deletions
diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index 9264adc97ca9..d7dddd6c296a 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -34,46 +34,51 @@
* 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>
+#include <linux/time.h>
-#define ICCR1_ICE 0x80
-#define ICCR1_IICRST 0x40
-#define ICCR1_SOWP 0x10
+#define ICCR1_ICE BIT(7)
+#define ICCR1_IICRST BIT(6)
+#define ICCR1_SOWP BIT(4)
+#define ICCR1_SCLI BIT(1)
+#define ICCR1_SDAI BIT(0)
-#define ICCR2_BBSY 0x80
-#define ICCR2_SP 0x08
-#define ICCR2_RS 0x04
-#define ICCR2_ST 0x02
+#define ICCR2_BBSY BIT(7)
+#define ICCR2_SP BIT(3)
+#define ICCR2_RS BIT(2)
+#define ICCR2_ST BIT(1)
-#define ICMR1_CKS_MASK 0x70
-#define ICMR1_BCWP 0x08
+#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 ICBR_RESERVED 0xe0 /* Should be 1 on writes */
+#define ICBR_RESERVED GENMASK(7, 5) /* Should be 1 on writes */
#define RIIC_INIT_MSG -1
@@ -134,6 +139,27 @@ 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 ret;
+
+ if ((riic_readb(riic, RIIC_ICCR1) & (ICCR1_SDAI | ICCR1_SCLI)) !=
+ (ICCR1_SDAI | ICCR1_SCLI))
+ return -EBUSY;
+
+ 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 +172,11 @@ 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);
@@ -312,6 +336,7 @@ 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 +345,7 @@ 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);
@@ -356,11 +381,9 @@ static int riic_init_hw(struct riic_dev *riic)
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 +400,9 @@ 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 +412,7 @@ 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)
@@ -416,7 +439,7 @@ static int riic_init_hw(struct riic_dev *riic)
return 0;
}
-static struct riic_irq_desc riic_irqs[] = {
+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" },
@@ -424,11 +447,6 @@ 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 int riic_i2c_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -445,35 +463,27 @@ 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");
-
- ret = reset_control_deassert(riic->rstc);
- if (ret)
- return ret;
-
- ret = devm_add_action_or_reset(dev, riic_reset_control_assert, riic->rstc);
- if (ret)
- return ret;
+ "failed to acquire deasserted reset\n");
for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {
- ret = platform_get_irq(pdev, riic_irqs[i].res_num);
- if (ret < 0)
- return ret;
+ int irq;
+
+ irq = platform_get_irq(pdev, riic_irqs[i].res_num);
+ if (irq < 0)
+ return irq;
- ret = devm_request_irq(dev, ret, riic_irqs[i].isr,
+ ret = devm_request_irq(dev, irq, 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;
- }
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to request irq %s\n",
+ riic_irqs[i].name);
}
riic->info = of_device_get_match_data(dev);
generated by cgit (git 2.34.1) at 2025-04-22 09:54:56 +0000