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authorGabe Black <gabeblack@google.com>2014-04-07 18:45:14 -0700
committerMarc Jones <marc.jones@se-eng.com>2014-12-16 00:02:43 +0100
commitcdb61a6f5d2268b059ac56da3b69ad0313f3fb90 (patch)
tree57dcfe80e68d872d1080cfc168abc866f0cbffe7 /src/cpu/allwinner/a10
parentbe6f8cb0f0a2873a9c16dc454cde1f29f4fab765 (diff)
downloadcoreboot-cdb61a6f5d2268b059ac56da3b69ad0313f3fb90.tar.xz
i2c: Replace the i2c API.
The new API is in use in depthcharge and is based around the "i2c_transfer" function instead of i2c_read and i2c_write. The new function takes an array of i2c_seg structures which represent each portion of the transfer after a start bit and before the stop bit. If there's more than one segment, they're seperated by repeated starts. Some wrapper functions have also been added which make certain common operations easy. These include reading or writing a byte from a register or reading or writing a blob of raw data. The i2c device drivers generally use these wrappers but can call the i2c_transfer function directly if the need something different. The tegra i2c driver was very similar to the one in depthcharge and was simple to convert. The Exynos 5250 and 5420 drivers were ported from depthcharge and replace the ones in coreboot. The Exynos 5420 driver was ported from the high speed portion of the one in coreboot and was straightforward to port back. The low speed portion and the Exynos 5250 drivers had been transplanted from U-Boot and were replaced with the depthcharge implementation. BUG=None TEST=Built and booted on nyan with and without EFS. Built and booted on, pit and daisy. BRANCH=None Original-Change-Id: I1e98c3fa2560be25444ab3d0394bb214b9d56e93 Original-Signed-off-by: Gabe Black <gabeblack@google.com> Original-Reviewed-on: https://chromium-review.googlesource.com/193561 Original-Reviewed-by: David Hendricks <dhendrix@chromium.org> Original-Reviewed-by: Jimmy Zhang <jimmzhang@nvidia.com> Original-Tested-by: Jimmy Zhang <jimmzhang@nvidia.com> Original-Reviewed-by: Hung-Te Lin <hungte@chromium.org> Original-Commit-Queue: Gabe Black <gabeblack@chromium.org> Original-Tested-by: Gabe Black <gabeblack@chromium.org> (cherry picked from commit 00c423fb2c06c69d580ee3ec0a3892ebf164a5fe) This cherry-pick required additional changes to the following: src/cpu/allwinner/a10/twi.c src/drivers/xpowers/axp209/axp209.c Signed-off-by: Marc Jones <marc.jones@se-eng.com> Change-Id: I691959c66308eeeec219b1bec463b8b365a246d7 Reviewed-on: http://review.coreboot.org/7751 Tested-by: build bot (Jenkins) Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Diffstat (limited to 'src/cpu/allwinner/a10')
-rw-r--r--src/cpu/allwinner/a10/twi.c40
1 files changed, 36 insertions, 4 deletions
diff --git a/src/cpu/allwinner/a10/twi.c b/src/cpu/allwinner/a10/twi.c
index 692a498a36..14e5ec7d9f 100644
--- a/src/cpu/allwinner/a10/twi.c
+++ b/src/cpu/allwinner/a10/twi.c
@@ -109,8 +109,8 @@ static void i2c_send_stop(struct a1x_twi *twi)
write32(reg32, &twi->ctl);
}
-int i2c_read(unsigned bus, unsigned chip, unsigned addr,
- unsigned alen, uint8_t *buf, unsigned len)
+static int i2c_read(unsigned bus, unsigned chip, unsigned addr,
+ uint8_t *buf, unsigned len)
{
unsigned count = len;
enum twi_status expected_status;
@@ -169,8 +169,8 @@ int i2c_read(unsigned bus, unsigned chip, unsigned addr,
return len;
}
-int i2c_write(unsigned bus, unsigned chip, unsigned addr,
- unsigned alen, const uint8_t *buf, unsigned len)
+static int i2c_write(unsigned bus, unsigned chip, unsigned addr,
+ const uint8_t *buf, unsigned len)
{
unsigned count = len;
struct a1x_twi *twi = (void *)TWI_BASE(bus);
@@ -204,3 +204,35 @@ int i2c_write(unsigned bus, unsigned chip, unsigned addr,
return len;
}
+
+
+/*
+ * This transfer function is not complete or correct, but it provides
+ * the basic support that the above read and write functions previously
+ * provided directly. It is extremely limited and not useful for
+ * advanced drivers like TPM.
+ *
+ * TODO: Rewite the i2c_transfer and supporting functions
+ *
+ */
+int i2c_transfer(unsigned bus, struct i2c_seg *segments, int count)
+{
+ struct i2c_seg *seg = segments;
+
+ if (seg->read) {
+ /* Read has one buf for the addr and one for the data */
+ if (count != 2)
+ return -1;
+
+ if(i2c_read(bus, seg->chip, *seg->buf, seg[1].buf, seg[1].len) < 0)
+ return -1;
+ } else {
+ /* Write buf has adder and data. */
+ if (count != 1)
+ return -1;
+
+ if(i2c_write(bus, seg->chip, *seg->buf, seg->buf+1, seg->len-1) < 0)
+ return -1;
+ }
+ return 0;
+}