58 lines
1.9 KiB
Diff
58 lines
1.9 KiB
Diff
From 0a09088e24c013ef608b1bb79501ef890cefc767 Mon Sep 17 00:00:00 2001
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From: Phil Elwell <phil@raspberrypi.com>
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Date: Tue, 19 Dec 2023 11:16:25 +0000
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Subject: [PATCH] i2c: designware: Look for *CNT values in DT
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The i2c-designware driver supports reading precise timing values from
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ACPI, but the Device Tree support relies on a combination of standard
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rise and fall times and hard-coded minimum timings. The result of this
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is that it is difficult to get optimum timings, particularly given that
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the values are bus speed-specific and only one set can be stored in
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DT at a time.
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Add support for initialisation from DT that is similar to that for
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ACPI.
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Signed-off-by: Phil Elwell <phil@raspberrypi.com>
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---
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drivers/i2c/busses/i2c-designware-platdrv.c | 18 ++++++++++++++++++
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1 file changed, 18 insertions(+)
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--- a/drivers/i2c/busses/i2c-designware-platdrv.c
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+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
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@@ -132,9 +132,18 @@ static int mscc_twi_set_sda_hold_time(st
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return 0;
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}
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+static void dw_i2c_read_of_cnt(struct device_node *np, const char *name, u16 *pval)
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+{
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+ u32 val;
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+
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+ if (!of_property_read_u32(np, name, &val))
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+ *pval = (u16)val;
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+}
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+
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static int dw_i2c_of_configure(struct platform_device *pdev)
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{
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struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
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+ struct device_node *np = pdev->dev.of_node;
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switch (dev->flags & MODEL_MASK) {
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case MODEL_MSCC_OCELOT:
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@@ -146,6 +155,15 @@ static int dw_i2c_of_configure(struct pl
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break;
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}
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+ dw_i2c_read_of_cnt(np, "snps,ss_hcnt", &dev->ss_hcnt);
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+ dw_i2c_read_of_cnt(np, "snps,ss_lcnt", &dev->ss_lcnt);
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+ dw_i2c_read_of_cnt(np, "snps,fs_hcnt", &dev->fs_hcnt);
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+ dw_i2c_read_of_cnt(np, "snps,fs_lcnt", &dev->fs_lcnt);
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+ dw_i2c_read_of_cnt(np, "snps,fp_hcnt", &dev->fp_hcnt);
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+ dw_i2c_read_of_cnt(np, "snps,fp_lcnt", &dev->fp_lcnt);
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+ dw_i2c_read_of_cnt(np, "snps,hs_hcnt", &dev->hs_hcnt);
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+ dw_i2c_read_of_cnt(np, "snps,hs_lcnt", &dev->hs_lcnt);
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+
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return 0;
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}
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