[PATCH 5/6] i2c: qcom-geni: add desc struct to prepare support for I2C Master Hub variant

Neil Armstrong
2022-11-16T10:22:19Z

Those I2C serial engines variants have some requirements:
- a separate "core" clock
- doesn't support DMA, thus no memory interconnect path
- fixed FIFO size not discoverable in the HW_PARAM_0 register

This adds a desc struct specifying all those requirements which
will be used in a next change when adding the I2C Master Hub
serial engine compatible.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
drivers/i2c/busses/i2c-qcom-geni.c | 50 +++++++++++++++++++++++++++++++++++---
1 file changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 84a77512614d..75dd0718c5a1 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -88,6 +88,7 @@ struct geni_i2c_dev {
int cur_wr;
int cur_rd;
spinlock_t lock;
+ struct clk *core_clk;
u32 clk_freq_out;
const struct geni_i2c_clk_fld *clk_fld;
int suspended;
@@ -100,6 +101,13 @@ struct geni_i2c_dev {
bool abort_done;
};

+struct geni_i2c_desc {
+ bool has_core_clk;
+ char *icc_ddr;
+ bool no_dma_support;
+ unsigned int tx_fifo_depth;
+};
+
struct geni_i2c_err_log {
int err;
const char *msg;
@@ -764,6 +772,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
u32 proto, tx_depth, fifo_disable;
int ret;
struct device *dev = &pdev->dev;
+ const struct geni_i2c_desc *desc = NULL;

gi2c = devm_kzalloc(dev, sizeof(*gi2c), GFP_KERNEL);
if (!gi2c)
@@ -776,6 +785,14 @@ static int geni_i2c_probe(struct platform_device *pdev)
if (IS_ERR(gi2c->se.base))
return PTR_ERR(gi2c->se.base);

+ desc = device_get_match_data(&pdev->dev);
+
+ if (desc && desc->has_core_clk) {
+ gi2c->core_clk = devm_clk_get(dev, "core");
+ if (IS_ERR(gi2c->core_clk))
+ return PTR_ERR(gi2c->core_clk);
+ }
+
gi2c->se.clk = devm_clk_get(dev, "se");
if (IS_ERR(gi2c->se.clk) && !has_acpi_companion(dev))
return PTR_ERR(gi2c->se.clk);
@@ -819,7 +836,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
gi2c->adap.dev.of_node = dev->of_node;
strscpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));

- ret = geni_icc_get(&gi2c->se, "qup-memory");
+ ret = geni_icc_get(&gi2c->se, desc ? desc->icc_ddr : "qup-memory");
if (ret)
return ret;
/*
@@ -829,12 +846,17 @@ static int geni_i2c_probe(struct platform_device *pdev)
*/
gi2c->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
gi2c->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
- gi2c->se.icc_paths[GENI_TO_DDR].avg_bw = Bps_to_icc(gi2c->clk_freq_out);
+ if (!desc || desc->icc_ddr)
+ gi2c->se.icc_paths[GENI_TO_DDR].avg_bw = Bps_to_icc(gi2c->clk_freq_out);

ret = geni_icc_set_bw(&gi2c->se);
if (ret)
return ret;

+ ret = clk_prepare_enable(gi2c->core_clk);
+ if (ret)
+ return ret;
+
ret = geni_se_resources_on(&gi2c->se);
if (ret) {
dev_err(dev, "Error turning on resources %d\n", ret);
@@ -844,10 +866,15 @@ static int geni_i2c_probe(struct platform_device *pdev)
if (proto != GENI_SE_I2C) {
dev_err(dev, "Invalid proto %d\n", proto);
geni_se_resources_off(&gi2c->se);
+ clk_disable_unprepare(gi2c->core_clk);
return -ENXIO;
}

- fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
+ if (desc && desc->no_dma_support)
+ fifo_disable = false;
+ else
+ fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
+
if (fifo_disable) {
/* FIFO is disabled, so we can only use GPI DMA */
gi2c->gpi_mode = true;
@@ -859,6 +886,16 @@ static int geni_i2c_probe(struct platform_device *pdev)
} else {
gi2c->gpi_mode = false;
tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
+
+ /* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */
+ if (!tx_depth && desc)
+ tx_depth = desc->tx_fifo_depth;
+
+ if (!tx_depth) {
+ dev_err(dev, "Invalid TX FIFO depth\n");
+ return -EINVAL;
+ }
+
gi2c->tx_wm = tx_depth - 1;
geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
geni_se_config_packing(&gi2c->se, BITS_PER_BYTE,
@@ -867,6 +904,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
}

+ clk_disable_unprepare(gi2c->core_clk);
ret = geni_se_resources_off(&gi2c->se);
if (ret) {
dev_err(dev, "Error turning off resources %d\n", ret);
@@ -932,6 +970,8 @@ static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
gi2c->suspended = 1;
}

+ clk_disable_unprepare(gi2c->core_clk);
+
return geni_icc_disable(&gi2c->se);
}

@@ -944,6 +984,10 @@ static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
if (ret)
return ret;

+ ret = clk_prepare_enable(gi2c->core_clk);
+ if (ret)
+ return ret;
+
ret = geni_se_resources_on(&gi2c->se);
if (ret)
return ret;

--
b4 0.10.1