Merge tag 'i2c-fixes-7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux

Pull i2c fix from Andi Shyti:

 - qcom-geni: select the correct source clock table entry

* tag 'i2c-fixes-7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux:
  i2c: qcom-geni: Fix hardcoded clock index in SE_GENI_CLK_SEL

1 files changed, 33 insertions, 5 deletions

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index e9e41a174c20..6a39e21d5ed4 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -82,6 +82,9 @@ enum geni_i2c_err_code {
 #define XFER_TIMEOUT		HZ
 #define RST_TIMEOUT		HZ
 
+#define GENI_SE_CLK_32MHZ	(32 * HZ_PER_MHZ)
+#define GENI_SE_CLK_19P2MHZ	19200000UL
+
 struct geni_i2c_desc {
 	bool no_dma_support;
 	unsigned int tx_fifo_depth;
@@ -127,6 +130,7 @@ struct geni_i2c_dev {
 	spinlock_t lock;
 	u32 clk_freq_out;
 	const struct geni_i2c_clk_fld *clk_fld;
+	u32 clk_idx;
 	void *dma_buf;
 	size_t xfer_len;
 	dma_addr_t dma_addr;
@@ -197,19 +201,44 @@ static const struct geni_i2c_clk_fld geni_i2c_clk_map_32mhz[] = {
 static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
 {
 	const struct geni_i2c_clk_fld *itr;
+	unsigned long res_freq;
 
-	if (clk_get_rate(gi2c->se.clk) == 32 * HZ_PER_MHZ)
+	/*
+	 * Frequency counter tables are calibrated for a specific source
+	 * clock frequency and are not valid for any multiple of it
+	 * (e.g. 64 MHz, 128 MHz).
+	 * Use exact=true and verify res_freq matches req_freq literally
+	 * to reject harmonics: a 64 MHz clock that divides evenly to
+	 * 32 MHz would pass exact matching but produce double the intended
+	 * I2C frequency with these counter values.
+	 */
+	if (!geni_se_clk_freq_match(&gi2c->se, GENI_SE_CLK_32MHZ,
+				    &gi2c->clk_idx, &res_freq, true) &&
+	    res_freq == GENI_SE_CLK_32MHZ) {
 		itr = geni_i2c_clk_map_32mhz;
-	else
+	} else if (!geni_se_clk_freq_match(&gi2c->se, GENI_SE_CLK_19P2MHZ,
+					   &gi2c->clk_idx, &res_freq, true) &&
+		   res_freq == GENI_SE_CLK_19P2MHZ) {
 		itr = geni_i2c_clk_map_19p2mhz;
+	} else {
+		dev_err(gi2c->se.dev,
+			"Unsupported SE source clock: must be exactly 32 MHz or 19.2 MHz\n");
+		return -EINVAL;
+	}
 
 	while (itr->clk_freq_out != 0) {
 		if (itr->clk_freq_out == gi2c->clk_freq_out) {
 			gi2c->clk_fld = itr;
+			dev_dbg(gi2c->se.dev,
+				"I2C clk selected: freq: %u Hz, clk_idx: %u\n",
+				gi2c->clk_freq_out, gi2c->clk_idx);
 			return 0;
 		}
 		itr++;
 	}
+
+	dev_err(gi2c->se.dev, "Unsupported I2C output frequency %u Hz\n", gi2c->clk_freq_out);
+
 	return -EINVAL;
 }
 
@@ -219,7 +248,7 @@ static int qcom_geni_i2c_conf(struct geni_se *se, unsigned long freq)
 	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
 	u32 val;
 
-	writel_relaxed(0, gi2c->se.base + SE_GENI_CLK_SEL);
+	writel_relaxed(gi2c->clk_idx, gi2c->se.base + SE_GENI_CLK_SEL);
 
 	val = (itr->clk_div << CLK_DIV_SHFT) | SER_CLK_EN;
 	writel_relaxed(val, gi2c->se.base + GENI_SER_M_CLK_CFG);
@@ -1111,8 +1140,7 @@ static int geni_i2c_resources_init(struct geni_se *se)
 
 	ret = geni_i2c_clk_map_idx(gi2c);
 	if (ret)
-		return dev_err_probe(gi2c->se.dev, ret, "Invalid clk frequency %d Hz\n",
-				     gi2c->clk_freq_out);
+		return ret;
 
 	return geni_icc_set_bw_ab(&gi2c->se, GENI_DEFAULT_BW, GENI_DEFAULT_BW,
 				  Bps_to_icc(gi2c->clk_freq_out));