[PATCH v2] i2c: busses: i2c-mt65xx: Simplify with clk-bulk

From: AngeloGioacchino Del Regno
Date: Thu Mar 03 2022 - 04:16:03 EST


Since depending on the SoC or specific bus functionality some clocks
may be optional, we cannot get the benefit of using devm_clk_bulk_get()
but, by migrating to clk-bulk, we are able to remove the custom functions
mtk_i2c_clock_enable() and mtk_i2c_clock_disable(), increasing common
APIs usage, hence (lightly) decreasing kernel footprint.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: Qii Wang <wii.wang@xxxxxxxxxxxx>
---

v2: Rebased on top of wsa/linux.git branch i2c/for-mergewindow

drivers/i2c/busses/i2c-mt65xx.c | 124 +++++++++++++-------------------
1 file changed, 51 insertions(+), 73 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 5bf7f965800d..7dde3b64766b 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -86,6 +86,27 @@

#define I2C_DRV_NAME "i2c-mt65xx"

+/**
+ * enum i2c_mt65xx_clks - Clocks enumeration for MT65XX I2C
+ *
+ * @I2C_MT65XX_CLK_MAIN: main clock for i2c bus
+ * @I2C_MT65XX_CLK_DMA: DMA clock for i2c via DMA
+ * @I2C_MT65XX_CLK_PMIC: PMIC clock for i2c from PMIC
+ * @I2C_MT65XX_CLK_ARB: Arbitrator clock for i2c
+ * @I2C_MT65XX_CLK_MAX: Number of supported clocks
+ */
+enum i2c_mt65xx_clks {
+ I2C_MT65XX_CLK_MAIN = 0,
+ I2C_MT65XX_CLK_DMA,
+ I2C_MT65XX_CLK_PMIC,
+ I2C_MT65XX_CLK_ARB,
+ I2C_MT65XX_CLK_MAX
+};
+
+static const char * const i2c_mt65xx_clk_ids[I2C_MT65XX_CLK_MAX] = {
+ "main", "dma", "pmic", "arb"
+};
+
enum DMA_REGS_OFFSET {
OFFSET_INT_FLAG = 0x0,
OFFSET_INT_EN = 0x04,
@@ -244,10 +265,7 @@ struct mtk_i2c {
/* set in i2c probe */
void __iomem *base; /* i2c base addr */
void __iomem *pdmabase; /* dma base address*/
- struct clk *clk_main; /* main clock for i2c bus */
- struct clk *clk_dma; /* DMA clock for i2c via DMA */
- struct clk *clk_pmic; /* PMIC clock for i2c from PMIC */
- struct clk *clk_arb; /* Arbitrator clock for i2c */
+ struct clk_bulk_data clocks[I2C_MT65XX_CLK_MAX]; /* clocks for i2c */
bool have_pmic; /* can use i2c pins from PMIC */
bool use_push_pull; /* IO config push-pull mode */

@@ -449,52 +467,6 @@ static void mtk_i2c_writew(struct mtk_i2c *i2c, u16 val,
writew(val, i2c->base + i2c->dev_comp->regs[reg]);
}

-static int mtk_i2c_clock_enable(struct mtk_i2c *i2c)
-{
- int ret;
-
- ret = clk_prepare_enable(i2c->clk_dma);
- if (ret)
- return ret;
-
- ret = clk_prepare_enable(i2c->clk_main);
- if (ret)
- goto err_main;
-
- if (i2c->have_pmic) {
- ret = clk_prepare_enable(i2c->clk_pmic);
- if (ret)
- goto err_pmic;
- }
-
- if (i2c->clk_arb) {
- ret = clk_prepare_enable(i2c->clk_arb);
- if (ret)
- goto err_arb;
- }
-
- return 0;
-
-err_arb:
- clk_disable_unprepare(i2c->clk_pmic);
-err_pmic:
- clk_disable_unprepare(i2c->clk_main);
-err_main:
- clk_disable_unprepare(i2c->clk_dma);
-
- return ret;
-}
-
-static void mtk_i2c_clock_disable(struct mtk_i2c *i2c)
-{
- clk_disable_unprepare(i2c->clk_arb);
-
- clk_disable_unprepare(i2c->clk_pmic);
-
- clk_disable_unprepare(i2c->clk_main);
- clk_disable_unprepare(i2c->clk_dma);
-}
-
static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
{
u16 control_reg;
@@ -1191,7 +1163,7 @@ static int mtk_i2c_transfer(struct i2c_adapter *adap,
int left_num = num;
struct mtk_i2c *i2c = i2c_get_adapdata(adap);

- ret = mtk_i2c_clock_enable(i2c);
+ ret = clk_bulk_prepare_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
if (ret)
return ret;

@@ -1245,7 +1217,7 @@ static int mtk_i2c_transfer(struct i2c_adapter *adap,
ret = num;

err_exit:
- mtk_i2c_clock_disable(i2c);
+ clk_bulk_disable_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);
return ret;
}

@@ -1323,9 +1295,8 @@ static int mtk_i2c_probe(struct platform_device *pdev)
{
int ret = 0;
struct mtk_i2c *i2c;
- struct clk *clk;
struct resource *res;
- int irq;
+ int i, irq, speed_clk;

i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
if (!i2c)
@@ -1371,35 +1342,42 @@ static int mtk_i2c_probe(struct platform_device *pdev)
if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c)
return -EINVAL;

- i2c->clk_main = devm_clk_get(&pdev->dev, "main");
- if (IS_ERR(i2c->clk_main)) {
+ /* Fill in clk-bulk IDs */
+ for (i = 0; i < I2C_MT65XX_CLK_MAX; i++)
+ i2c->clocks[i].id = i2c_mt65xx_clk_ids[i];
+
+ /* Get clocks one by one, some may be optional */
+ i2c->clocks[I2C_MT65XX_CLK_MAIN].clk = devm_clk_get(&pdev->dev, "main");
+ if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_MAIN].clk)) {
dev_err(&pdev->dev, "cannot get main clock\n");
- return PTR_ERR(i2c->clk_main);
+ return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_MAIN].clk);
}

- i2c->clk_dma = devm_clk_get(&pdev->dev, "dma");
- if (IS_ERR(i2c->clk_dma)) {
+ i2c->clocks[I2C_MT65XX_CLK_DMA].clk = devm_clk_get(&pdev->dev, "dma");
+ if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_DMA].clk)) {
dev_err(&pdev->dev, "cannot get dma clock\n");
- return PTR_ERR(i2c->clk_dma);
+ return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_DMA].clk);
}

- i2c->clk_arb = devm_clk_get(&pdev->dev, "arb");
- if (IS_ERR(i2c->clk_arb))
- i2c->clk_arb = NULL;
+ i2c->clocks[I2C_MT65XX_CLK_ARB].clk = devm_clk_get_optional(&pdev->dev, "arb");
+ if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_ARB].clk))
+ return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_ARB].clk);

- clk = i2c->clk_main;
if (i2c->have_pmic) {
- i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic");
- if (IS_ERR(i2c->clk_pmic)) {
+ i2c->clocks[I2C_MT65XX_CLK_PMIC].clk = devm_clk_get(&pdev->dev, "pmic");
+ if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk)) {
dev_err(&pdev->dev, "cannot get pmic clock\n");
- return PTR_ERR(i2c->clk_pmic);
+ return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk);
}
- clk = i2c->clk_pmic;
+ speed_clk = I2C_MT65XX_CLK_PMIC;
+ } else {
+ i2c->clocks[I2C_MT65XX_CLK_PMIC].clk = NULL;
+ speed_clk = I2C_MT65XX_CLK_MAIN;
}

strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));

- ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk));
+ ret = mtk_i2c_set_speed(i2c, clk_get_rate(i2c->clocks[speed_clk].clk));
if (ret) {
dev_err(&pdev->dev, "Failed to set the speed.\n");
return -EINVAL;
@@ -1414,13 +1392,13 @@ static int mtk_i2c_probe(struct platform_device *pdev)
}
}

- ret = mtk_i2c_clock_enable(i2c);
+ ret = clk_bulk_prepare_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
if (ret) {
dev_err(&pdev->dev, "clock enable failed!\n");
return ret;
}
mtk_i2c_init_hw(i2c);
- mtk_i2c_clock_disable(i2c);
+ clk_bulk_disable_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);

ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
IRQF_NO_SUSPEND | IRQF_TRIGGER_NONE,
@@ -1465,7 +1443,7 @@ static int mtk_i2c_resume_noirq(struct device *dev)
int ret;
struct mtk_i2c *i2c = dev_get_drvdata(dev);

- ret = mtk_i2c_clock_enable(i2c);
+ ret = clk_bulk_prepare_enable(I2C_MT65XX_CLK_MAX, i2c->clocks);
if (ret) {
dev_err(dev, "clock enable failed!\n");
return ret;
@@ -1473,7 +1451,7 @@ static int mtk_i2c_resume_noirq(struct device *dev)

mtk_i2c_init_hw(i2c);

- mtk_i2c_clock_disable(i2c);
+ clk_bulk_disable_unprepare(I2C_MT65XX_CLK_MAX, i2c->clocks);

i2c_mark_adapter_resumed(&i2c->adap);

--
2.35.1